From de03507853b8fab2fb08a3f540acd5849b61684c Mon Sep 17 00:00:00 2001
From: Cody Tapscott <84105208+topolarity@users.noreply.github.com>
Date: Wed, 26 Feb 2025 19:15:21 -0500
Subject: [PATCH 1/6] Remove usages of weak symbols (#57522)

Inspired by a bug I hit on MinGW recently with weak symbol resolution.
I'm not sure why we started using these in
70000ac7c3d5d5f21e42555cdf99e699a246f8ec, since I believe we should be
able to lookup these symbols just fine in our `jl_exe_handle` as long as
it was linked / compiled with `-rdynamic`

Migrating away from weak symbols seems a good idea, given their uneven
implementation across platforms.

(cherry picked from commit 4a6ada6eb36eaeb9bde9b94c01bcf6f0e3ce7ae6)
---
 src/Makefile         |  8 +++++---
 src/julia_internal.h | 18 ------------------
 src/null_sysimage.c  | 15 +++++++++++++++
 src/processor.cpp    | 11 +++--------
 src/processor.h      | 12 ++++++++++++
 src/staticdata.c     | 27 ++++++++++++++-------------
 src/threading.c      | 15 ++-------------
 7 files changed, 51 insertions(+), 55 deletions(-)
 create mode 100644 src/null_sysimage.c

diff --git a/src/Makefile b/src/Makefile
index bf9001e5fba93..c25649d2cab7c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -46,7 +46,8 @@ SRCS := \
 	simplevector runtime_intrinsics precompile jloptions mtarraylist \
 	threading scheduler stackwalk gc gc-debug gc-pages gc-stacks gc-alloc-profiler gc-page-profiler method \
 	jlapi signal-handling safepoint timing subtype rtutils gc-heap-snapshot \
-	crc32c APInt-C processor ircode opaque_closure codegen-stubs coverage runtime_ccall
+	crc32c APInt-C processor ircode opaque_closure codegen-stubs coverage runtime_ccall \
+	null_sysimage
 
 RT_LLVMLINK :=
 CG_LLVMLINK :=
@@ -56,7 +57,8 @@ CODEGEN_SRCS := codegen jitlayers aotcompile debuginfo disasm llvm-simdloop llvm
 	llvm-final-gc-lowering llvm-pass-helpers llvm-late-gc-lowering llvm-ptls \
 	llvm-lower-handlers llvm-gc-invariant-verifier llvm-propagate-addrspaces \
 	llvm-multiversioning llvm-alloc-opt llvm-alloc-helpers cgmemmgr llvm-remove-addrspaces \
-	llvm-remove-ni llvm-julia-licm llvm-demote-float16 llvm-cpufeatures pipeline llvm_api
+	llvm-remove-ni llvm-julia-licm llvm-demote-float16 llvm-cpufeatures pipeline llvm_api \
+	null_sysimage
 FLAGS += -I$(shell $(LLVM_CONFIG_HOST) --includedir)
 CG_LLVM_LIBS := all
 ifeq ($(USE_POLLY),1)
@@ -160,7 +162,7 @@ endif
 CLANG_LDFLAGS := $(LLVM_LDFLAGS)
 ifeq ($(OS), Darwin)
 CLANG_LDFLAGS += -Wl,-undefined,dynamic_lookup
-OSLIBS += -Wl,-U,__dyld_atfork_parent -Wl,-U,__dyld_atfork_prepare -Wl,-U,__dyld_dlopen_atfork_parent -Wl,-U,__dyld_dlopen_atfork_prepare -Wl,-U,_jl_image_pointers -Wl,-U,_jl_system_image_data -Wl,-U,_jl_system_image_size
+OSLIBS += -Wl,-U,__dyld_atfork_parent -Wl,-U,__dyld_atfork_prepare -Wl,-U,__dyld_dlopen_atfork_parent -Wl,-U,__dyld_dlopen_atfork_prepare
 LIBJULIA_PATH_REL := @rpath/libjulia
 else
 LIBJULIA_PATH_REL := libjulia
diff --git a/src/julia_internal.h b/src/julia_internal.h
index 72d9dfdad5c7e..dff769e7e0f66 100644
--- a/src/julia_internal.h
+++ b/src/julia_internal.h
@@ -1710,24 +1710,6 @@ jl_sym_t *_jl_symbol(const char *str, size_t len) JL_NOTSAFEPOINT;
   #define JL_GC_ASSERT_LIVE(x) (void)(x)
 #endif
 
-#ifdef _OS_WINDOWS_
-// On Windows, weak symbols do not default to 0 due to a GCC bug
-// (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90826), use symbol
-// aliases with a known value instead.
-#define JL_WEAK_SYMBOL_OR_ALIAS_DEFAULT(sym) __attribute__((weak,alias(#sym)))
-#define JL_WEAK_SYMBOL_DEFAULT(sym) &sym
-#else
-#define JL_WEAK_SYMBOL_OR_ALIAS_DEFAULT(sym) __attribute__((weak))
-#define JL_WEAK_SYMBOL_DEFAULT(sym) NULL
-#endif
-
-//JL_DLLEXPORT float julia__gnu_h2f_ieee(half param) JL_NOTSAFEPOINT;
-//JL_DLLEXPORT half julia__gnu_f2h_ieee(float param) JL_NOTSAFEPOINT;
-//JL_DLLEXPORT half julia__truncdfhf2(double param) JL_NOTSAFEPOINT;
-//JL_DLLEXPORT float julia__truncsfbf2(float param) JL_NOTSAFEPOINT;
-//JL_DLLEXPORT float julia__truncdfbf2(double param) JL_NOTSAFEPOINT;
-//JL_DLLEXPORT double julia__extendhfdf2(half n) JL_NOTSAFEPOINT;
-
 JL_DLLEXPORT uint32_t jl_crc32c(uint32_t crc, const char *buf, size_t len);
 
 // -- exports from codegen -- //
diff --git a/src/null_sysimage.c b/src/null_sysimage.c
new file mode 100644
index 0000000000000..386842f0c4e77
--- /dev/null
+++ b/src/null_sysimage.c
@@ -0,0 +1,15 @@
+// This file is a part of Julia. License is MIT: https://julialang.org/license
+
+#include <stddef.h>
+#include "processor.h"
+
+/**
+ * These symbols support statically linking the sysimage with libjulia-internal.
+ *
+ * Here we provide dummy definitions that are used when these are not linked
+ * together (the default build configuration). The 0 value of jl_system_image_size
+ * is used as a sentinel to indicate that the sysimage should be loaded externally.
+ **/
+char jl_system_image_data = 0;
+size_t jl_system_image_size = 0;
+jl_image_pointers_t jl_image_pointers = { 0 };
diff --git a/src/processor.cpp b/src/processor.cpp
index 730e470f4153d..ed50c609895cc 100644
--- a/src/processor.cpp
+++ b/src/processor.cpp
@@ -619,11 +619,6 @@ static inline llvm::SmallVector<TargetData<n>, 0> &get_cmdline_targets(F &&featu
     return targets;
 }
 
-extern "C" {
-void *image_pointers_unavailable;
-extern void * JL_WEAK_SYMBOL_OR_ALIAS_DEFAULT(image_pointers_unavailable) jl_image_pointers;
-}
-
 // Load sysimg, use the `callback` for dispatch and perform all relocations
 // for the selected target.
 template<typename F>
@@ -633,10 +628,10 @@ static inline jl_image_t parse_sysimg(void *hdl, F &&callback)
     jl_image_t res{};
 
     const jl_image_pointers_t *pointers;
-    if (hdl == jl_exe_handle && &jl_image_pointers != JL_WEAK_SYMBOL_DEFAULT(image_pointers_unavailable))
-        pointers = (const jl_image_pointers_t *)&jl_image_pointers;
-    else
+    if (jl_system_image_size == 0)
         jl_dlsym(hdl, "jl_image_pointers", (void**)&pointers, 1);
+    else
+        pointers = &jl_image_pointers; // libjulia-internal and sysimage statically linked
 
     const void *ids = pointers->target_data;
     jl_value_t* rejection_reason = nullptr;
diff --git a/src/processor.h b/src/processor.h
index 82a1121aaf7c4..214f51845b12d 100644
--- a/src/processor.h
+++ b/src/processor.h
@@ -224,6 +224,18 @@ JL_DLLEXPORT int32_t jl_set_zero_subnormals(int8_t isZero);
 JL_DLLEXPORT int32_t jl_get_zero_subnormals(void);
 JL_DLLEXPORT int32_t jl_set_default_nans(int8_t isDefault);
 JL_DLLEXPORT int32_t jl_get_default_nans(void);
+
+/**
+ * System image contents.
+ *
+ * These symbols are typically dummy values, unless statically linking
+ * libjulia-* and the sysimage together (see null_sysimage.c), in which
+ * case they allow accessing the local copy of the sysimage.
+ **/
+extern char jl_system_image_data;
+extern size_t jl_system_image_size;
+extern jl_image_pointers_t jl_image_pointers;
+
 #ifdef __cplusplus
 }
 
diff --git a/src/staticdata.c b/src/staticdata.c
index cac3b78545cca..793a2ccd19574 100644
--- a/src/staticdata.c
+++ b/src/staticdata.c
@@ -620,24 +620,25 @@ JL_DLLEXPORT int jl_running_on_valgrind(void)
     return RUNNING_ON_VALGRIND;
 }
 
-void *system_image_data_unavailable;
-extern void * JL_WEAK_SYMBOL_OR_ALIAS_DEFAULT(system_image_data_unavailable) jl_system_image_data;
-extern void * JL_WEAK_SYMBOL_OR_ALIAS_DEFAULT(system_image_data_unavailable) jl_system_image_size;
 static void jl_load_sysimg_so(void)
 {
-    const char *sysimg_data;
     assert(sysimage.fptrs.ptrs); // jl_init_processor_sysimg should already be run
-    if (jl_sysimg_handle == jl_exe_handle &&
-            &jl_system_image_data != JL_WEAK_SYMBOL_DEFAULT(system_image_data_unavailable))
-        sysimg_data = (const char*)&jl_system_image_data;
-    else
-        jl_dlsym(jl_sysimg_handle, "jl_system_image_data", (void **)&sysimg_data, 1);
+
     size_t *plen;
-    if (jl_sysimg_handle == jl_exe_handle &&
-            &jl_system_image_size != JL_WEAK_SYMBOL_DEFAULT(system_image_data_unavailable))
-        plen = (size_t *)&jl_system_image_size;
-    else
+    const char *sysimg_data;
+
+    if (jl_system_image_size == 0) {
+        // in the usual case, the sysimage was not statically linked to libjulia-internal
+        // look up the external sysimage symbols via the dynamic linker
         jl_dlsym(jl_sysimg_handle, "jl_system_image_size", (void **)&plen, 1);
+        jl_dlsym(jl_sysimg_handle, "jl_system_image_data", (void **)&sysimg_data, 1);
+    } else {
+        // the sysimage was statically linked directly against libjulia-internal
+        // use the internal symbols
+        plen = &jl_system_image_size;
+        sysimg_data = &jl_system_image_data;
+    }
+
     jl_restore_system_image_data(sysimg_data, *plen);
 }
 
diff --git a/src/threading.c b/src/threading.c
index 62af7e60bf0f1..a17d3b371acf5 100644
--- a/src/threading.c
+++ b/src/threading.c
@@ -250,10 +250,6 @@ void jl_set_pgcstack(jl_gcframe_t **pgcstack) JL_NOTSAFEPOINT
 {
     *jl_pgcstack_key() = pgcstack;
 }
-#  if JL_USE_IFUNC
-JL_DLLEXPORT __attribute__((weak))
-void jl_register_pgcstack_getter(void);
-#  endif
 static jl_gcframe_t **jl_get_pgcstack_init(void);
 static jl_get_pgcstack_func *jl_get_pgcstack_cb = jl_get_pgcstack_init;
 static jl_gcframe_t **jl_get_pgcstack_init(void)
@@ -266,15 +262,8 @@ static jl_gcframe_t **jl_get_pgcstack_init(void)
     // This is clearly not thread-safe but should be fine since we
     // make sure the tls states callback is finalized before adding
     // multiple threads
-#  if JL_USE_IFUNC
-    if (jl_register_pgcstack_getter)
-        jl_register_pgcstack_getter();
-    else
-#  endif
-    {
-        jl_get_pgcstack_cb = jl_get_pgcstack_fallback;
-        jl_pgcstack_key = &jl_pgcstack_addr_fallback;
-    }
+    jl_get_pgcstack_cb = jl_get_pgcstack_fallback;
+    jl_pgcstack_key = &jl_pgcstack_addr_fallback;
     return jl_get_pgcstack_cb();
 }
 

From b4c714a7127d69d3e3ea8d648a94310c6e2157e7 Mon Sep 17 00:00:00 2001
From: Cody Tapscott <84105208+topolarity@users.noreply.github.com>
Date: Thu, 27 Feb 2025 22:20:02 -0500
Subject: [PATCH 2/6] staticdata: Refactor sysimage loading (#57542)

Introduce `jl_image_buf_t` to represent the in-memory details of an
unparsed system image and clean-up several global variables and split
loading logic in staticdata.c so that we get (almost) everything we need
from the sysimage handle at once.

This allows sysimage loading to be separated into three phases:
  1. Lookup the raw sysimage buffer as a `jl_image_buf_t`
2. For .so sysimages, parse the sysimage and initialize JIT targets,
etc.
  3. Finally load the sysimage into a `jl_image_t`

Care was taken to preserve the existing behavior of calling
`jl_set_sysimg_so` to configure the sysimage before initializing Julia,
although this is likely to be next on the chopping block in a follow-up.

Dependent on #57523.
---
 src/aotcompile.cpp           |   2 +-
 src/init.c                   |  28 +++--
 src/jitlayers.cpp            |   2 +-
 src/jl_exported_funcs.inc    |   3 +-
 src/julia.h                  |  26 ++++-
 src/llvm-multiversioning.cpp |   2 +-
 src/processor.cpp            |  33 ++----
 src/processor.h              |  13 ++-
 src/processor_arm.cpp        |  33 +++---
 src/processor_fallback.cpp   |  33 +++---
 src/processor_x86.cpp        |  34 +++---
 src/staticdata.c             | 208 ++++++++++++++++++++---------------
 test/cmdlineargs.jl          |   2 +-
 13 files changed, 235 insertions(+), 184 deletions(-)

diff --git a/src/aotcompile.cpp b/src/aotcompile.cpp
index 97734852f9479..05853828d36ce 100644
--- a/src/aotcompile.cpp
+++ b/src/aotcompile.cpp
@@ -1833,7 +1833,7 @@ void jl_dump_native_impl(void *native_code,
             builder.CreateRet(ConstantInt::get(T_int32, 1));
         }
         if (imaging_mode) {
-            auto specs = jl_get_llvm_clone_targets();
+            auto specs = jl_get_llvm_clone_targets(jl_options.cpu_target);
             const uint32_t base_flags = has_veccall ? JL_TARGET_VEC_CALL : 0;
             SmallVector<uint8_t, 0> data;
             auto push_i32 = [&] (uint32_t v) {
diff --git a/src/init.c b/src/init.c
index a5c9a6b19f94d..3517aa9d8fa5a 100644
--- a/src/init.c
+++ b/src/init.c
@@ -847,19 +847,30 @@ static NOINLINE void _finish_julia_init(JL_IMAGE_SEARCH rel, jl_ptls_t ptls, jl_
 {
     JL_TIMING(JULIA_INIT, JULIA_INIT);
     jl_resolve_sysimg_location(rel);
+
     // loads sysimg if available, and conditionally sets jl_options.cpu_target
-    if (rel == JL_IMAGE_IN_MEMORY)
-        jl_set_sysimg_so(jl_exe_handle);
+    jl_image_buf_t sysimage = { JL_IMAGE_KIND_NONE };
+    if (rel == JL_IMAGE_IN_MEMORY) {
+        sysimage = jl_set_sysimg_so(jl_exe_handle);
+        jl_options.image_file = jl_options.julia_bin;
+    }
     else if (jl_options.image_file)
-        jl_preload_sysimg_so(jl_options.image_file);
+        sysimage = jl_preload_sysimg(jl_options.image_file);
+
     if (jl_options.cpu_target == NULL)
         jl_options.cpu_target = "native";
-    jl_init_codegen();
 
+    // Parse image, perform relocations, and init JIT targets, etc.
+    jl_image_t parsed_image = jl_init_processor_sysimg(sysimage, jl_options.cpu_target);
+
+    jl_init_codegen();
     jl_init_common_symbols();
-    if (jl_options.image_file) {
-        jl_restore_system_image(jl_options.image_file);
+
+    if (sysimage.kind != JL_IMAGE_KIND_NONE) {
+        // Load the .ji or .so sysimage
+        jl_restore_system_image(&parsed_image, sysimage);
     } else {
+        // No sysimage provided, init a minimal environment
         jl_init_types();
         jl_global_roots_list = (jl_genericmemory_t*)jl_an_empty_memory_any;
         jl_global_roots_keyset = (jl_genericmemory_t*)jl_an_empty_memory_any;
@@ -868,7 +879,7 @@ static NOINLINE void _finish_julia_init(JL_IMAGE_SEARCH rel, jl_ptls_t ptls, jl_
     jl_init_flisp();
     jl_init_serializer();
 
-    if (!jl_options.image_file) {
+    if (sysimage.kind == JL_IMAGE_KIND_NONE) {
         jl_top_module = jl_core_module;
         jl_init_intrinsic_functions();
         jl_init_primitives();
@@ -892,7 +903,8 @@ static NOINLINE void _finish_julia_init(JL_IMAGE_SEARCH rel, jl_ptls_t ptls, jl_
 
     jl_gc_enable(1);
 
-    if (jl_options.image_file && (!jl_generating_output() || jl_options.incremental) && jl_module_init_order) {
+    if ((sysimage.kind != JL_IMAGE_KIND_NONE) &&
+            (!jl_generating_output() || jl_options.incremental) && jl_module_init_order) {
         jl_array_t *init_order = jl_module_init_order;
         JL_GC_PUSH1(&init_order);
         jl_module_init_order = NULL;
diff --git a/src/jitlayers.cpp b/src/jitlayers.cpp
index b3ed1e069de16..e418ce06a74a7 100644
--- a/src/jitlayers.cpp
+++ b/src/jitlayers.cpp
@@ -1139,7 +1139,7 @@ namespace {
         options.ExplicitEmulatedTLS = true;
 #endif
         uint32_t target_flags = 0;
-        auto target = jl_get_llvm_target(imaging_default(), target_flags);
+        auto target = jl_get_llvm_target(jl_options.cpu_target, jl_generating_output(), target_flags);
         auto &TheCPU = target.first;
         SmallVector<std::string, 10> targetFeatures(target.second.begin(), target.second.end());
         std::string errorstr;
diff --git a/src/jl_exported_funcs.inc b/src/jl_exported_funcs.inc
index 05057cfd80861..66db481187b47 100644
--- a/src/jl_exported_funcs.inc
+++ b/src/jl_exported_funcs.inc
@@ -370,7 +370,7 @@
     XX(jl_pointerset) \
     XX(jl_pop_handler) \
     XX(jl_pop_handler_noexcept) \
-    XX(jl_preload_sysimg_so) \
+    XX(jl_preload_sysimg) \
     XX(jl_prepend_cwd) \
     XX(jl_printf) \
     XX(jl_print_backtrace) \
@@ -400,7 +400,6 @@
     XX(jl_restore_incremental) \
     XX(jl_restore_package_image_from_file) \
     XX(jl_restore_system_image) \
-    XX(jl_restore_system_image_data) \
     XX(jl_rethrow) \
     XX(jl_rethrow_other) \
     XX(jl_running_on_valgrind) \
diff --git a/src/julia.h b/src/julia.h
index 2bb8bc5d0b59f..b8783ff821d00 100644
--- a/src/julia.h
+++ b/src/julia.h
@@ -2030,6 +2030,25 @@ typedef enum {
     JL_IMAGE_IN_MEMORY = 2
 } JL_IMAGE_SEARCH;
 
+typedef enum {
+    JL_IMAGE_KIND_NONE = 0,
+    JL_IMAGE_KIND_JI,
+    JL_IMAGE_KIND_SO,
+} jl_image_kind_t;
+
+// A loaded, but unparsed .ji or .so image file
+typedef struct {
+    jl_image_kind_t kind;
+    void *handle;
+    const void *pointers; // jl_image_pointers_t *
+    const char *data;
+    size_t size;
+    uint64_t base;
+} jl_image_buf_t;
+
+struct _jl_image_t;
+typedef struct _jl_image_t jl_image_t;
+
 JL_DLLIMPORT const char *jl_get_libdir(void);
 JL_DLLEXPORT void julia_init(JL_IMAGE_SEARCH rel);
 JL_DLLEXPORT void jl_init(void);
@@ -2046,11 +2065,10 @@ JL_DLLEXPORT const char *jl_pathname_for_handle(void *handle);
 JL_DLLEXPORT jl_gcframe_t **jl_adopt_thread(void);
 
 JL_DLLEXPORT int jl_deserialize_verify_header(ios_t *s);
-JL_DLLEXPORT void jl_preload_sysimg_so(const char *fname);
-JL_DLLEXPORT void jl_set_sysimg_so(void *handle);
+JL_DLLEXPORT jl_image_buf_t jl_preload_sysimg(const char *fname);
+JL_DLLEXPORT jl_image_buf_t jl_set_sysimg_so(void *handle);
 JL_DLLEXPORT void jl_create_system_image(void **, jl_array_t *worklist, bool_t emit_split, ios_t **s, ios_t **z, jl_array_t **udeps, int64_t *srctextpos);
-JL_DLLEXPORT void jl_restore_system_image(const char *fname);
-JL_DLLEXPORT void jl_restore_system_image_data(const char *buf, size_t len);
+JL_DLLEXPORT void jl_restore_system_image(jl_image_t *image, jl_image_buf_t buf);
 JL_DLLEXPORT jl_value_t *jl_restore_incremental(const char *fname, jl_array_t *depmods, int complete, const char *pkgimage);
 
 JL_DLLEXPORT void jl_set_newly_inferred(jl_value_t *newly_inferred);
diff --git a/src/llvm-multiversioning.cpp b/src/llvm-multiversioning.cpp
index 1901a721e5e08..299213090f064 100644
--- a/src/llvm-multiversioning.cpp
+++ b/src/llvm-multiversioning.cpp
@@ -215,7 +215,7 @@ static void annotate_module_clones(Module &M) {
     if (auto maybe_specs = get_target_specs(M)) {
         specs = std::move(*maybe_specs);
     } else {
-        auto full_specs = jl_get_llvm_clone_targets();
+        auto full_specs = jl_get_llvm_clone_targets(jl_options.cpu_target);
         specs.reserve(full_specs.size());
         for (auto &spec: full_specs) {
             specs.push_back(TargetSpec::fromSpec(spec));
diff --git a/src/processor.cpp b/src/processor.cpp
index ed50c609895cc..28f5d80d77cd2 100644
--- a/src/processor.cpp
+++ b/src/processor.cpp
@@ -504,7 +504,8 @@ static inline llvm::SmallVector<TargetData<n>, 0>
 parse_cmdline(const char *option, F &&feature_cb)
 {
     if (!option)
-        option = "native";
+        abort();
+
     llvm::SmallVector<TargetData<n>, 0> res;
     TargetData<n> arg{};
     auto reset_arg = [&] {
@@ -612,31 +613,29 @@ parse_cmdline(const char *option, F &&feature_cb)
 
 // Cached version of command line parsing
 template<size_t n, typename F>
-static inline llvm::SmallVector<TargetData<n>, 0> &get_cmdline_targets(F &&feature_cb)
+static inline llvm::SmallVector<TargetData<n>, 0> &get_cmdline_targets(const char *cpu_target, F &&feature_cb)
 {
     static llvm::SmallVector<TargetData<n>, 0> targets =
-        parse_cmdline<n>(jl_options.cpu_target, std::forward<F>(feature_cb));
+        parse_cmdline<n>(cpu_target, std::forward<F>(feature_cb));
     return targets;
 }
 
 // Load sysimg, use the `callback` for dispatch and perform all relocations
 // for the selected target.
 template<typename F>
-static inline jl_image_t parse_sysimg(void *hdl, F &&callback)
+static inline jl_image_t parse_sysimg(jl_image_buf_t image, F &&callback, void *ctx)
 {
     JL_TIMING(LOAD_IMAGE, LOAD_Processor);
     jl_image_t res{};
 
-    const jl_image_pointers_t *pointers;
-    if (jl_system_image_size == 0)
-        jl_dlsym(hdl, "jl_image_pointers", (void**)&pointers, 1);
-    else
-        pointers = &jl_image_pointers; // libjulia-internal and sysimage statically linked
+    if (image.kind != JL_IMAGE_KIND_SO)
+        return res;
 
+    const jl_image_pointers_t *pointers = (const jl_image_pointers_t *)image.pointers;
     const void *ids = pointers->target_data;
     jl_value_t* rejection_reason = nullptr;
     JL_GC_PUSH1(&rejection_reason);
-    uint32_t target_idx = callback(ids, &rejection_reason);
+    uint32_t target_idx = callback(ctx, ids, &rejection_reason);
     if (target_idx == UINT32_MAX) {
         jl_error(jl_string_ptr(rejection_reason));
     }
@@ -794,17 +793,7 @@ static inline jl_image_t parse_sysimg(void *hdl, F &&callback)
         res.fptrs.nclones = clones.size();
     }
 
-#ifdef _OS_WINDOWS_
-    res.base = (intptr_t)hdl;
-#else
-    Dl_info dlinfo;
-    if (dladdr((void*)pointers, &dlinfo) != 0) {
-        res.base = (intptr_t)dlinfo.dli_fbase;
-    }
-    else {
-        res.base = 0;
-    }
-#endif
+    res.base = image.base;
 
     {
         void *pgcstack_func_slot = pointers->ptls->pgcstack_func_slot;
@@ -1020,7 +1009,7 @@ JL_DLLEXPORT jl_value_t *jl_get_cpu_features(void)
 }
 
 extern "C" JL_DLLEXPORT jl_value_t* jl_reflect_clone_targets() {
-    auto specs = jl_get_llvm_clone_targets();
+    auto specs = jl_get_llvm_clone_targets(jl_options.cpu_target);
     const uint32_t base_flags = 0;
     llvm::SmallVector<uint8_t, 0> data;
     auto push_i32 = [&] (uint32_t v) {
diff --git a/src/processor.h b/src/processor.h
index 214f51845b12d..65b634fd0ba26 100644
--- a/src/processor.h
+++ b/src/processor.h
@@ -64,6 +64,7 @@ JL_DLLEXPORT int jl_test_cpu_feature(jl_cpu_feature_t feature);
 static const uint32_t jl_sysimg_tag_mask = 0x80000000u;
 static const uint32_t jl_sysimg_val_mask = ~((uint32_t)0x80000000u);
 
+// A parsed image file
 typedef struct _jl_image_fptrs_t {
     // number of functions
     uint32_t nptrs;
@@ -82,14 +83,14 @@ typedef struct _jl_image_fptrs_t {
     const uint32_t *clone_idxs;
 } jl_image_fptrs_t;
 
-typedef struct {
+struct _jl_image_t {
     uint64_t base;
     const char *gvars_base;
     const int32_t *gvars_offsets;
     uint32_t ngvars;
     jl_image_fptrs_t fptrs;
     void **jl_small_typeof;
-} jl_image_t;
+};
 
 // The header for each image
 // Details important counts about the image
@@ -206,8 +207,8 @@ typedef struct {
  *
  * Return the data about the function pointers selected.
  */
-jl_image_t jl_init_processor_sysimg(void *hdl);
-jl_image_t jl_init_processor_pkgimg(void *hdl);
+jl_image_t jl_init_processor_sysimg(jl_image_buf_t image, const char *cpu_target);
+jl_image_t jl_init_processor_pkgimg(jl_image_buf_t image);
 
 // Return the name of the host CPU as a julia string.
 JL_DLLEXPORT jl_value_t *jl_get_cpu_name(void);
@@ -251,7 +252,7 @@ extern JL_DLLEXPORT bool jl_processor_print_help;
  * If the detected/specified CPU name is not available on the LLVM version specified,
  * a fallback CPU name will be used. Unsupported features will be ignored.
  */
-extern "C" JL_DLLEXPORT std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(bool imaging, uint32_t &flags) JL_NOTSAFEPOINT;
+extern "C" JL_DLLEXPORT std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(const char *cpu_target, bool imaging, uint32_t &flags) JL_NOTSAFEPOINT;
 
 /**
  * Returns the CPU name and feature string to be used by LLVM disassembler.
@@ -275,7 +276,7 @@ struct jl_target_spec_t {
 /**
  * Return the list of targets to clone
  */
-extern "C" JL_DLLEXPORT llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(void) JL_NOTSAFEPOINT;
+extern "C" JL_DLLEXPORT llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(const char *cpu_target) JL_NOTSAFEPOINT;
 // NOLINTEND(clang-diagnostic-return-type-c-linkage)
 struct FeatureName {
     const char *name;
diff --git a/src/processor_arm.cpp b/src/processor_arm.cpp
index 0d9009afabec7..7df2b74773af4 100644
--- a/src/processor_arm.cpp
+++ b/src/processor_arm.cpp
@@ -1510,7 +1510,7 @@ static inline void disable_depends(FeatureList<n> &features)
     ::disable_depends(features, Feature::deps, sizeof(Feature::deps) / sizeof(FeatureDep));
 }
 
-static const llvm::SmallVector<TargetData<feature_sz>, 0> &get_cmdline_targets(void)
+static const llvm::SmallVector<TargetData<feature_sz>, 0> &get_cmdline_targets(const char *cpu_target)
 {
     auto feature_cb = [] (const char *str, size_t len, FeatureList<feature_sz> &list) {
 #ifdef _CPU_AARCH64_
@@ -1527,7 +1527,7 @@ static const llvm::SmallVector<TargetData<feature_sz>, 0> &get_cmdline_targets(v
         set_bit(list, fbit, true);
         return true;
     };
-    auto &targets = ::get_cmdline_targets<feature_sz>(feature_cb);
+    auto &targets = ::get_cmdline_targets<feature_sz>(cpu_target, feature_cb);
     for (auto &t: targets) {
         if (auto nname = normalize_cpu_name(t.name)) {
             t.name = nname;
@@ -1590,10 +1590,11 @@ static int max_vector_size(const FeatureList<feature_sz> &features)
 #endif
 }
 
-static uint32_t sysimg_init_cb(const void *id, jl_value_t **rejection_reason)
+static uint32_t sysimg_init_cb(void *ctx, const void *id, jl_value_t **rejection_reason)
 {
     // First see what target is requested for the JIT.
-    auto &cmdline = get_cmdline_targets();
+    const char *cpu_target = (const char *)ctx;
+    auto &cmdline = get_cmdline_targets(cpu_target);
     TargetData<feature_sz> target = arg_target_data(cmdline[0], true);
     // Then find the best match in the sysimg
     auto sysimg = deserialize_target_data<feature_sz>((const uint8_t*)id);
@@ -1617,7 +1618,7 @@ static uint32_t sysimg_init_cb(const void *id, jl_value_t **rejection_reason)
     return match.best_idx;
 }
 
-static uint32_t pkgimg_init_cb(const void *id, jl_value_t **rejection_reason JL_REQUIRE_ROOTED_SLOT)
+static uint32_t pkgimg_init_cb(void *ctx, const void *id, jl_value_t **rejection_reason JL_REQUIRE_ROOTED_SLOT)
 {
     TargetData<feature_sz> target = jit_targets.front();
     auto pkgimg = deserialize_target_data<feature_sz>((const uint8_t*)id);
@@ -1630,9 +1631,9 @@ static uint32_t pkgimg_init_cb(const void *id, jl_value_t **rejection_reason JL_
     return match.best_idx;
 }
 
-static void ensure_jit_target(bool imaging)
+static void ensure_jit_target(const char *cpu_target, bool imaging)
 {
-    auto &cmdline = get_cmdline_targets();
+    auto &cmdline = get_cmdline_targets(cpu_target);
     check_cmdline(cmdline, imaging);
     if (!jit_targets.empty())
         return;
@@ -1843,36 +1844,36 @@ JL_DLLEXPORT jl_value_t *jl_cpu_has_fma(int bits)
 #endif
 }
 
-jl_image_t jl_init_processor_sysimg(void *hdl)
+jl_image_t jl_init_processor_sysimg(jl_image_buf_t image, const char *cpu_target)
 {
     if (!jit_targets.empty())
         jl_error("JIT targets already initialized");
-    return parse_sysimg(hdl, sysimg_init_cb);
+    return parse_sysimg(image, sysimg_init_cb, (void *)cpu_target);
 }
 
-jl_image_t jl_init_processor_pkgimg(void *hdl)
+jl_image_t jl_init_processor_pkgimg(jl_image_buf_t image)
 {
     if (jit_targets.empty())
         jl_error("JIT targets not initialized");
     if (jit_targets.size() > 1)
         jl_error("Expected only one JIT target");
-    return parse_sysimg(hdl, pkgimg_init_cb);
+    return parse_sysimg(image, pkgimg_init_cb, NULL);
 }
 
 JL_DLLEXPORT jl_value_t* jl_check_pkgimage_clones(char *data)
 {
     jl_value_t *rejection_reason = NULL;
     JL_GC_PUSH1(&rejection_reason);
-    uint32_t match_idx = pkgimg_init_cb(data, &rejection_reason);
+    uint32_t match_idx = pkgimg_init_cb(NULL, data, &rejection_reason);
     JL_GC_POP();
     if (match_idx == UINT32_MAX)
         return rejection_reason;
     return jl_nothing;
 }
 
-std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(bool imaging, uint32_t &flags)
+std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(const char *cpu_target, bool imaging, uint32_t &flags)
 {
-    ensure_jit_target(imaging);
+    ensure_jit_target(cpu_target, imaging);
     flags = jit_targets[0].en.flags;
     return get_llvm_target_vec(jit_targets[0]);
 }
@@ -1891,10 +1892,10 @@ const std::pair<std::string,std::string> &jl_get_llvm_disasm_target(void)
 }
 
 #ifndef __clang_gcanalyzer__
-llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(void)
+llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(const char *cpu_target)
 {
 
-    auto &cmdline = get_cmdline_targets();
+    auto &cmdline = get_cmdline_targets(cpu_target);
     check_cmdline(cmdline, true);
     llvm::SmallVector<TargetData<feature_sz>, 0> image_targets;
     for (auto &arg: cmdline) {
diff --git a/src/processor_fallback.cpp b/src/processor_fallback.cpp
index f8d9eb9fd9e73..c8c8feb072345 100644
--- a/src/processor_fallback.cpp
+++ b/src/processor_fallback.cpp
@@ -13,12 +13,12 @@ static inline const std::string &host_cpu_name()
     return name;
 }
 
-static const llvm::SmallVector<TargetData<1>, 0> &get_cmdline_targets(void)
+static const llvm::SmallVector<TargetData<1>, 0> &get_cmdline_targets(const char *cpu_target)
 {
     auto feature_cb = [] (const char*, size_t, FeatureList<1>&) {
         return false;
     };
-    return ::get_cmdline_targets<1>(feature_cb);
+    return ::get_cmdline_targets<1>(cpu_target, feature_cb);
 }
 
 static llvm::SmallVector<TargetData<1>, 0> jit_targets;
@@ -36,10 +36,11 @@ static TargetData<1> arg_target_data(const TargetData<1> &arg, bool require_host
     return res;
 }
 
-static uint32_t sysimg_init_cb(const void *id, jl_value_t **rejection_reason)
+static uint32_t sysimg_init_cb(void *ctx, const void *id, jl_value_t **rejection_reason)
 {
     // First see what target is requested for the JIT.
-    auto &cmdline = get_cmdline_targets();
+    const char *cpu_target = (const char *)ctx;
+    auto &cmdline = get_cmdline_targets(cpu_target);
     TargetData<1> target = arg_target_data(cmdline[0], true);
     // Find the last name match or use the default one.
     uint32_t best_idx = 0;
@@ -54,7 +55,7 @@ static uint32_t sysimg_init_cb(const void *id, jl_value_t **rejection_reason)
     return best_idx;
 }
 
-static uint32_t pkgimg_init_cb(const void *id, jl_value_t **rejection_reason)
+static uint32_t pkgimg_init_cb(void *ctx, const void *id, jl_value_t **rejection_reason)
 {
     TargetData<1> target = jit_targets.front();
     // Find the last name match or use the default one.
@@ -70,9 +71,9 @@ static uint32_t pkgimg_init_cb(const void *id, jl_value_t **rejection_reason)
     return best_idx;
 }
 
-static void ensure_jit_target(bool imaging)
+static void ensure_jit_target(const char *cpu_target, bool imaging)
 {
-    auto &cmdline = get_cmdline_targets();
+    auto &cmdline = get_cmdline_targets(cpu_target);
     check_cmdline(cmdline, imaging);
     if (!jit_targets.empty())
         return;
@@ -115,25 +116,25 @@ get_llvm_target_str(const TargetData<1> &data)
 
 using namespace Fallback;
 
-jl_image_t jl_init_processor_sysimg(void *hdl)
+jl_image_t jl_init_processor_sysimg(jl_image_buf_t image, const char *cpu_target)
 {
     if (!jit_targets.empty())
         jl_error("JIT targets already initialized");
-    return parse_sysimg(hdl, sysimg_init_cb);
+    return parse_sysimg(image, sysimg_init_cb, (void *)cpu_target);
 }
 
-jl_image_t jl_init_processor_pkgimg(void *hdl)
+jl_image_t jl_init_processor_pkgimg(jl_image_buf_t image)
 {
     if (jit_targets.empty())
         jl_error("JIT targets not initialized");
     if (jit_targets.size() > 1)
         jl_error("Expected only one JIT target");
-    return parse_sysimg(hdl, pkgimg_init_cb);
+    return parse_sysimg(image, pkgimg_init_cb, NULL);
 }
 
-std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(bool imaging, uint32_t &flags)
+std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(const char *cpu_target, bool imaging, uint32_t &flags)
 {
-    ensure_jit_target(imaging);
+    ensure_jit_target(cpu_target, imaging);
     flags = jit_targets[0].en.flags;
     return get_llvm_target_vec(jit_targets[0]);
 }
@@ -145,10 +146,10 @@ const std::pair<std::string,std::string> &jl_get_llvm_disasm_target(void)
     return res;
 }
 #ifndef __clang_gcanalyzer__
-llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(void)
+llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(const char *cpu_target)
 {
 
-    auto &cmdline = get_cmdline_targets();
+    auto &cmdline = get_cmdline_targets(cpu_target);
     check_cmdline(cmdline, true);
     llvm::SmallVector<TargetData<1>, 0> image_targets;
     for (auto &arg: cmdline) {
@@ -192,7 +193,7 @@ JL_DLLEXPORT jl_value_t* jl_check_pkgimage_clones(char *data)
 {
     jl_value_t *rejection_reason = NULL;
     JL_GC_PUSH1(&rejection_reason);
-    uint32_t match_idx = pkgimg_init_cb(data, &rejection_reason);
+    uint32_t match_idx = pkgimg_init_cb(NULL, data, &rejection_reason);
     JL_GC_POP();
     if (match_idx == UINT32_MAX)
         return rejection_reason;
diff --git a/src/processor_x86.cpp b/src/processor_x86.cpp
index db954680289ea..dbd3de8bffa0c 100644
--- a/src/processor_x86.cpp
+++ b/src/processor_x86.cpp
@@ -782,7 +782,7 @@ static inline void disable_depends(FeatureList<n> &features)
     ::disable_depends(features, Feature::deps, sizeof(Feature::deps) / sizeof(FeatureDep));
 }
 
-static const llvm::SmallVector<TargetData<feature_sz>, 0> &get_cmdline_targets(void)
+static const llvm::SmallVector<TargetData<feature_sz>, 0> &get_cmdline_targets(const char *cpu_target)
 {
     auto feature_cb = [] (const char *str, size_t len, FeatureList<feature_sz> &list) {
         auto fbit = find_feature_bit(feature_names, nfeature_names, str, len);
@@ -791,7 +791,7 @@ static const llvm::SmallVector<TargetData<feature_sz>, 0> &get_cmdline_targets(v
         set_bit(list, fbit, true);
         return true;
     };
-    auto &targets = ::get_cmdline_targets<feature_sz>(feature_cb);
+    auto &targets = ::get_cmdline_targets<feature_sz>(cpu_target, feature_cb);
     for (auto &t: targets) {
         if (auto nname = normalize_cpu_name(t.name)) {
             t.name = nname;
@@ -851,10 +851,11 @@ static int max_vector_size(const FeatureList<feature_sz> &features)
     return 16;
 }
 
-static uint32_t sysimg_init_cb(const void *id, jl_value_t** rejection_reason)
+static uint32_t sysimg_init_cb(void *ctx, const void *id, jl_value_t** rejection_reason)
 {
     // First see what target is requested for the JIT.
-    auto &cmdline = get_cmdline_targets();
+    const char *cpu_target = (const char *)ctx;
+    auto &cmdline = get_cmdline_targets(cpu_target);
     TargetData<feature_sz> target = arg_target_data(cmdline[0], true);
     // Then find the best match in the sysimg
     auto sysimg = deserialize_target_data<feature_sz>((const uint8_t*)id);
@@ -897,7 +898,7 @@ static uint32_t sysimg_init_cb(const void *id, jl_value_t** rejection_reason)
     return match.best_idx;
 }
 
-static uint32_t pkgimg_init_cb(const void *id, jl_value_t **rejection_reason)
+static uint32_t pkgimg_init_cb(void *ctx, const void *id, jl_value_t **rejection_reason)
 {
     TargetData<feature_sz> target = jit_targets.front();
     auto pkgimg = deserialize_target_data<feature_sz>((const uint8_t*)id);
@@ -912,9 +913,9 @@ static uint32_t pkgimg_init_cb(const void *id, jl_value_t **rejection_reason)
 
 //This function serves as a fallback during bootstrapping, at that point we don't have a sysimage with native code
 // so we won't call sysimg_init_cb, else this function shouldn't do anything.
-static void ensure_jit_target(bool imaging)
+static void ensure_jit_target(const char *cpu_target, bool imaging)
 {
-    auto &cmdline = get_cmdline_targets();
+    auto &cmdline = get_cmdline_targets(cpu_target);
     check_cmdline(cmdline, imaging);
     if (!jit_targets.empty())
         return;
@@ -1058,7 +1059,7 @@ JL_DLLEXPORT jl_value_t* jl_check_pkgimage_clones(char *data)
 {
     jl_value_t *rejection_reason = NULL;
     JL_GC_PUSH1(&rejection_reason);
-    uint32_t match_idx = pkgimg_init_cb(data, &rejection_reason);
+    uint32_t match_idx = pkgimg_init_cb(NULL, data, &rejection_reason);
     JL_GC_POP();
     if (match_idx == UINT32_MAX)
         return rejection_reason;
@@ -1075,25 +1076,25 @@ JL_DLLEXPORT jl_value_t *jl_cpu_has_fma(int bits)
         return jl_false;
 }
 
-jl_image_t jl_init_processor_sysimg(void *hdl)
+jl_image_t jl_init_processor_sysimg(jl_image_buf_t image, const char *cpu_target)
 {
     if (!jit_targets.empty())
         jl_error("JIT targets already initialized");
-    return parse_sysimg(hdl, sysimg_init_cb);
+    return parse_sysimg(image, sysimg_init_cb, (void *)cpu_target);
 }
 
-jl_image_t jl_init_processor_pkgimg(void *hdl)
+jl_image_t jl_init_processor_pkgimg(jl_image_buf_t image)
 {
     if (jit_targets.empty())
         jl_error("JIT targets not initialized");
     if (jit_targets.size() > 1)
         jl_error("Expected only one JIT target");
-    return parse_sysimg(hdl, pkgimg_init_cb);
+    return parse_sysimg(image, pkgimg_init_cb, NULL);
 }
 
-std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(bool imaging, uint32_t &flags)
+std::pair<std::string,llvm::SmallVector<std::string, 0>> jl_get_llvm_target(const char *cpu_target, bool imaging, uint32_t &flags)
 {
-    ensure_jit_target(imaging);
+    ensure_jit_target(cpu_target, imaging);
     flags = jit_targets[0].en.flags;
     return get_llvm_target_vec(jit_targets[0]);
 }
@@ -1106,9 +1107,10 @@ const std::pair<std::string,std::string> &jl_get_llvm_disasm_target(void)
 }
 //This function parses the -C command line to figure out which targets to multiversion to.
 #ifndef __clang_gcanalyzer__
-llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(void)
+llvm::SmallVector<jl_target_spec_t, 0> jl_get_llvm_clone_targets(const char *cpu_target)
 {
-    auto &cmdline = get_cmdline_targets();
+
+    auto &cmdline = get_cmdline_targets(cpu_target);
     check_cmdline(cmdline, true);
     llvm::SmallVector<TargetData<feature_sz>, 0> image_targets;
     for (auto &arg: cmdline) {
diff --git a/src/staticdata.c b/src/staticdata.c
index 793a2ccd19574..3376933eed038 100644
--- a/src/staticdata.c
+++ b/src/staticdata.c
@@ -607,8 +607,7 @@ typedef struct {
 } pkgcachesizes;
 
 // --- Static Compile ---
-static void *jl_sysimg_handle = NULL;
-static jl_image_t sysimage;
+static jl_image_buf_t jl_sysimage_buf = { JL_IMAGE_KIND_NONE };
 
 static inline uintptr_t *sysimg_gvars(const char *base, const int32_t *offsets, size_t idx)
 {
@@ -620,29 +619,6 @@ JL_DLLEXPORT int jl_running_on_valgrind(void)
     return RUNNING_ON_VALGRIND;
 }
 
-static void jl_load_sysimg_so(void)
-{
-    assert(sysimage.fptrs.ptrs); // jl_init_processor_sysimg should already be run
-
-    size_t *plen;
-    const char *sysimg_data;
-
-    if (jl_system_image_size == 0) {
-        // in the usual case, the sysimage was not statically linked to libjulia-internal
-        // look up the external sysimage symbols via the dynamic linker
-        jl_dlsym(jl_sysimg_handle, "jl_system_image_size", (void **)&plen, 1);
-        jl_dlsym(jl_sysimg_handle, "jl_system_image_data", (void **)&sysimg_data, 1);
-    } else {
-        // the sysimage was statically linked directly against libjulia-internal
-        // use the internal symbols
-        plen = &jl_system_image_size;
-        sysimg_data = &jl_system_image_data;
-    }
-
-    jl_restore_system_image_data(sysimg_data, *plen);
-}
-
-
 // --- serializer ---
 
 #define NBOX_C 1024
@@ -3058,33 +3034,111 @@ JL_DLLEXPORT void jl_create_system_image(void **_native_data, jl_array_t *workli
 
 JL_DLLEXPORT size_t ios_write_direct(ios_t *dest, ios_t *src);
 
-// Takes in a path of the form "usr/lib/julia/sys.so" (jl_restore_system_image should be passed the same string)
-JL_DLLEXPORT void jl_preload_sysimg_so(const char *fname)
+// Takes in a path of the form "usr/lib/julia/sys.so"
+JL_DLLEXPORT jl_image_buf_t jl_preload_sysimg(const char *fname)
 {
-    if (jl_sysimg_handle)
-        return; // embedded target already called jl_set_sysimg_so
+    if (jl_sysimage_buf.kind != JL_IMAGE_KIND_NONE)
+        return jl_sysimage_buf;
 
     char *dot = (char*) strrchr(fname, '.');
     int is_ji = (dot && !strcmp(dot, ".ji"));
 
-    // Get handle to sys.so
-    if (!is_ji) // .ji extension => load .ji file only
-        jl_set_sysimg_so(jl_load_dynamic_library(fname, JL_RTLD_LOCAL | JL_RTLD_NOW, 1));
+    if (is_ji) {
+        // .ji extension => load .ji file only
+        ios_t f;
+
+        if (ios_file(&f, fname, 1, 0, 0, 0) == NULL)
+            jl_errorf("System image file \"%s\" not found.", fname);
+        ios_bufmode(&f, bm_none);
+
+        JL_SIGATOMIC_BEGIN();
+
+        ios_seek_end(&f);
+        size_t len = ios_pos(&f);
+        char *sysimg = (char*)jl_gc_perm_alloc(len, 0, 64, 0);
+        ios_seek(&f, 0);
+
+        if (ios_readall(&f, sysimg, len) != len)
+            jl_errorf("Error reading system image file.");
+
+        ios_close(&f);
+
+        JL_SIGATOMIC_END();
+
+        jl_sysimage_buf = (jl_image_buf_t) {
+            .kind = JL_IMAGE_KIND_JI,
+            .handle = NULL,
+            .pointers = NULL,
+            .data = sysimg,
+            .size = len,
+            .base = 0,
+        };
+        return jl_sysimage_buf;
+    } else {
+        // Get handle to sys.so
+        return jl_set_sysimg_so(jl_load_dynamic_library(fname, JL_RTLD_LOCAL | JL_RTLD_NOW, 1));
+    }
 }
 
-// Allow passing in a module handle directly, rather than a path
-JL_DLLEXPORT void jl_set_sysimg_so(void *handle)
+// From a shared library handle, verify consistency and return a jl_image_buf_t
+static jl_image_buf_t get_image_buf(void *handle, int is_pkgimage)
 {
+    size_t *plen;
+    const char *data;
+    const void *pointers;
+    uint64_t base;
+
+    // verify that the linker resolved the symbols in this image against ourselves (libjulia-internal)
     void** (*get_jl_RTLD_DEFAULT_handle_addr)(void) = NULL;
     if (handle != jl_RTLD_DEFAULT_handle) {
         int symbol_found = jl_dlsym(handle, "get_jl_RTLD_DEFAULT_handle_addr", (void **)&get_jl_RTLD_DEFAULT_handle_addr, 0);
         if (!symbol_found || (void*)&jl_RTLD_DEFAULT_handle != (get_jl_RTLD_DEFAULT_handle_addr()))
-            jl_error("System image file failed consistency check: maybe opened the wrong version?");
+            jl_error("Image file failed consistency check: maybe opened the wrong version?");
     }
-    if (jl_options.cpu_target == NULL)
-        jl_options.cpu_target = "native";
-    jl_sysimg_handle = handle;
-    sysimage = jl_init_processor_sysimg(handle);
+
+    // verification passed, lookup the buffer pointers
+    if (jl_system_image_size == 0 || is_pkgimage) {
+        // in the usual case, the sysimage was not statically linked to libjulia-internal
+        // look up the external sysimage symbols via the dynamic linker
+        jl_dlsym(handle, "jl_system_image_size", (void **)&plen, 1);
+        jl_dlsym(handle, "jl_system_image_data", (void **)&data, 1);
+        jl_dlsym(handle, "jl_image_pointers", (void**)&pointers, 1);
+    } else {
+        // the sysimage was statically linked directly against libjulia-internal
+        // use the internal symbols
+        plen = &jl_system_image_size;
+        pointers = &jl_image_pointers;
+        data = &jl_system_image_data;
+    }
+
+#ifdef _OS_WINDOWS_
+    base = (intptr_t)handle;
+#else
+    Dl_info dlinfo;
+    if (dladdr((void*)pointers, &dlinfo) != 0)
+        base = (intptr_t)dlinfo.dli_fbase;
+    else
+        base = 0;
+#endif
+
+    return (jl_image_buf_t) {
+        .kind = JL_IMAGE_KIND_SO,
+        .handle = handle,
+        .pointers = pointers,
+        .data = data,
+        .size = *plen,
+        .base = base,
+    };
+}
+
+// Allow passing in a module handle directly, rather than a path
+JL_DLLEXPORT jl_image_buf_t jl_set_sysimg_so(void *handle)
+{
+    if (jl_sysimage_buf.kind != JL_IMAGE_KIND_NONE)
+        return jl_sysimage_buf;
+
+    jl_sysimage_buf = get_image_buf(handle, /* is_pkgimage */ 0);
+    return jl_sysimage_buf;
 }
 
 #ifndef JL_NDEBUG
@@ -3104,7 +3158,8 @@ extern void export_jl_small_typeof(void);
 // into the native code of the image. See https://github.com/JuliaLang/julia/pull/52123#issuecomment-1959965395.
 int IMAGE_NATIVE_CODE_TAINTED = 0;
 
-static void jl_restore_system_image_from_stream_(ios_t *f, jl_image_t *image, jl_array_t *depmods, uint64_t checksum,
+static void jl_restore_system_image_from_stream_(ios_t *f, jl_image_t *image, void *image_handle,
+                                                 jl_array_t *depmods, uint64_t checksum,
                                 /* outputs */    jl_array_t **restored,         jl_array_t **init_order,
                                                  jl_array_t **extext_methods, jl_array_t **internal_methods,
                                                  jl_array_t **new_ext_cis, jl_array_t **method_roots_list,
@@ -3569,8 +3624,7 @@ static void jl_restore_system_image_from_stream_(ios_t *f, jl_image_t *image, jl
     s.s = &sysimg;
     jl_update_all_fptrs(&s, image); // fptr relocs and registration
     if (!ccallable_list) {
-        // TODO: jl_sysimg_handle or img_handle?
-        jl_reinit_ccallable(&s.ccallable_list, image_base, jl_sysimg_handle);
+        jl_reinit_ccallable(&s.ccallable_list, image_base, image_handle);
         arraylist_free(&s.ccallable_list);
     }
     s.s = NULL;
@@ -3668,7 +3722,7 @@ static jl_value_t *jl_restore_package_image_from_stream(void* pkgimage_handle, i
                 ios_close(f);
             ios_static_buffer(f, sysimg, len);
             pkgcachesizes cachesizes;
-            jl_restore_system_image_from_stream_(f, image, depmods, checksum, (jl_array_t**)&restored, &init_order, &extext_methods, &internal_methods, &new_ext_cis, &method_roots_list,
+            jl_restore_system_image_from_stream_(f, image, pkgimage_handle, depmods, checksum, (jl_array_t**)&restored, &init_order, &extext_methods, &internal_methods, &new_ext_cis, &method_roots_list,
                                                  &ext_targets, &edges, &base, &ccallable_list, &cachesizes);
             JL_SIGATOMIC_END();
 
@@ -3717,16 +3771,16 @@ static jl_value_t *jl_restore_package_image_from_stream(void* pkgimage_handle, i
     return restored;
 }
 
-static void jl_restore_system_image_from_stream(ios_t *f, jl_image_t *image, uint32_t checksum)
+static void jl_restore_system_image_from_stream(ios_t *f, jl_image_t *image, void *image_handle, uint32_t checksum)
 {
     JL_TIMING(LOAD_IMAGE, LOAD_Sysimg);
-    jl_restore_system_image_from_stream_(f, image, NULL, checksum | ((uint64_t)0xfdfcfbfa << 32), NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
+    jl_restore_system_image_from_stream_(f, image, image_handle, NULL, checksum | ((uint64_t)0xfdfcfbfa << 32), NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
 }
 
-JL_DLLEXPORT jl_value_t *jl_restore_incremental_from_buf(void* pkgimage_handle, const char *buf, jl_image_t *image, size_t sz, jl_array_t *depmods, int completeinfo, const char *pkgname, int needs_permalloc)
+JL_DLLEXPORT jl_value_t *jl_restore_incremental_from_buf(void* pkgimage_handle, jl_image_buf_t buf, jl_image_t *image, jl_array_t *depmods, int completeinfo, const char *pkgname, int needs_permalloc)
 {
     ios_t f;
-    ios_static_buffer(&f, (char*)buf, sz);
+    ios_static_buffer(&f, (char*)buf.data, buf.size);
     jl_value_t *ret = jl_restore_package_image_from_stream(pkgimage_handle, &f, image, depmods, completeinfo, pkgname, needs_permalloc);
     ios_close(&f);
     return ret;
@@ -3745,47 +3799,22 @@ JL_DLLEXPORT jl_value_t *jl_restore_incremental(const char *fname, jl_array_t *d
     return ret;
 }
 
-// TODO: need to enforce that the alignment of the buffer is suitable for vectors
-JL_DLLEXPORT void jl_restore_system_image(const char *fname)
+JL_DLLEXPORT void jl_restore_system_image(jl_image_t *image, jl_image_buf_t buf)
 {
-#ifndef JL_NDEBUG
-    char *dot = fname ? (char*)strrchr(fname, '.') : NULL;
-    int is_ji = (dot && !strcmp(dot, ".ji"));
-    assert((is_ji || jl_sysimg_handle) && "System image file not preloaded");
-#endif
+    ios_t f;
 
-    if (jl_sysimg_handle) {
-        // load the pre-compiled sysimage from jl_sysimg_handle
-        jl_load_sysimg_so();
-    }
-    else {
-        ios_t f;
-        if (ios_file(&f, fname, 1, 0, 0, 0) == NULL)
-            jl_errorf("System image file \"%s\" not found.", fname);
-        ios_bufmode(&f, bm_none);
-        JL_SIGATOMIC_BEGIN();
-        ios_seek_end(&f);
-        size_t len = ios_pos(&f);
-        char *sysimg = (char*)jl_gc_perm_alloc(len, 0, 64, 0);
-        ios_seek(&f, 0);
-        if (ios_readall(&f, sysimg, len) != len)
-            jl_errorf("Error reading system image file.");
-        ios_close(&f);
-        uint32_t checksum = jl_crc32c(0, sysimg, len);
-        ios_static_buffer(&f, sysimg, len);
-        jl_restore_system_image_from_stream(&f, &sysimage, checksum);
-        ios_close(&f);
-        JL_SIGATOMIC_END();
-    }
-}
+    if (buf.kind == JL_IMAGE_KIND_NONE)
+        return;
+
+    if (buf.kind == JL_IMAGE_KIND_SO)
+        assert(image->fptrs.ptrs); // jl_init_processor_sysimg should already be run
 
-JL_DLLEXPORT void jl_restore_system_image_data(const char *buf, size_t len)
-{
-    ios_t f;
     JL_SIGATOMIC_BEGIN();
-    ios_static_buffer(&f, (char*)buf, len);
-    uint32_t checksum = jl_crc32c(0, buf, len);
-    jl_restore_system_image_from_stream(&f, &sysimage, checksum);
+    ios_static_buffer(&f, (char *)buf.data, buf.size);
+
+    uint32_t checksum = jl_crc32c(0, buf.data, buf.size);
+    jl_restore_system_image_from_stream(&f, image, buf.handle, checksum);
+
     ios_close(&f);
     JL_SIGATOMIC_END();
 }
@@ -3804,12 +3833,11 @@ JL_DLLEXPORT jl_value_t *jl_restore_package_image_from_file(const char *fname, j
 #endif
         jl_errorf("Error opening package file %s: %s\n", fname, reason);
     }
-    const char *pkgimg_data;
-    jl_dlsym(pkgimg_handle, "jl_system_image_data", (void **)&pkgimg_data, 1);
-    size_t *plen;
-    jl_dlsym(pkgimg_handle, "jl_system_image_size", (void **)&plen, 1);
 
-    jl_image_t pkgimage = jl_init_processor_pkgimg(pkgimg_handle);
+    jl_image_buf_t buf = get_image_buf(pkgimg_handle, /* is_pkgimage */ 1);
+
+    // Despite the name, this function actually parses the pkgimage
+    jl_image_t pkgimage = jl_init_processor_pkgimg(buf);
 
     if (ignore_native) {
         // Must disable using native code in possible downstream users of this code:
@@ -3818,7 +3846,7 @@ JL_DLLEXPORT jl_value_t *jl_restore_package_image_from_file(const char *fname, j
         IMAGE_NATIVE_CODE_TAINTED = 1;
     }
 
-    jl_value_t* mod = jl_restore_incremental_from_buf(pkgimg_handle, pkgimg_data, &pkgimage, *plen, depmods, completeinfo, pkgname, 0);
+    jl_value_t* mod = jl_restore_incremental_from_buf(pkgimg_handle, buf, &pkgimage, depmods, completeinfo, pkgname, 0);
 
     return mod;
 }
diff --git a/test/cmdlineargs.jl b/test/cmdlineargs.jl
index 43cdf5e2696a6..1c70c5d3f2cab 100644
--- a/test/cmdlineargs.jl
+++ b/test/cmdlineargs.jl
@@ -979,7 +979,7 @@ let exename = `$(Base.julia_cmd().exec[1]) -t 1`
         p = run(pipeline(`$exename --sysimage=$libjulia`, stderr=err), wait=false)
         close(err.in)
         let s = read(err, String)
-            @test s == "ERROR: System image file failed consistency check: maybe opened the wrong version?\n"
+            @test s == "ERROR: Image file failed consistency check: maybe opened the wrong version?\n"
         end
         @test errors_not_signals(p)
         @test p.exitcode == 1

From 84f1db5746b82ccfafebf805d3a725e65f572e90 Mon Sep 17 00:00:00 2001
From: Jameson Nash <vtjnash@gmail.com>
Date: Tue, 20 May 2025 16:54:18 -0400
Subject: [PATCH 3/6] [deps] enable zstd support (backport, no LLVM) (#58344)

---
 Make.inc                         | 11 ++++-
 Makefile                         |  1 +
 THIRDPARTY.md                    |  1 +
 contrib/refresh_checksums.mk     |  2 +-
 deps/Makefile                    |  9 +++-
 deps/checksums/zstd              | 38 +++++++++++++++++
 deps/zstd.mk                     | 60 ++++++++++++++++++++++++++
 deps/zstd.version                |  8 ++++
 julia.spdx.json                  | 17 ++++++++
 src/Makefile                     |  5 ++-
 stdlib/Makefile                  |  2 +-
 stdlib/Manifest.toml             |  5 +++
 stdlib/Zstd_jll/Project.toml     | 15 +++++++
 stdlib/Zstd_jll/src/Zstd_jll.jl  | 73 ++++++++++++++++++++++++++++++++
 stdlib/Zstd_jll/test/runtests.jl |  7 +++
 stdlib/stdlib.mk                 |  2 +-
 16 files changed, 249 insertions(+), 7 deletions(-)
 create mode 100644 deps/checksums/zstd
 create mode 100644 deps/zstd.mk
 create mode 100644 deps/zstd.version
 create mode 100644 stdlib/Zstd_jll/Project.toml
 create mode 100644 stdlib/Zstd_jll/src/Zstd_jll.jl
 create mode 100644 stdlib/Zstd_jll/test/runtests.jl

diff --git a/Make.inc b/Make.inc
index e0bc8ba224a6d..b45886c2af963 100644
--- a/Make.inc
+++ b/Make.inc
@@ -65,6 +65,7 @@ USE_SYSTEM_LIBGIT2:=0
 USE_SYSTEM_PATCHELF:=0
 USE_SYSTEM_LIBWHICH:=0
 USE_SYSTEM_ZLIB:=0
+USE_SYSTEM_ZSTD:=0
 USE_SYSTEM_P7ZIP:=0
 USE_SYSTEM_LLD:=0
 
@@ -1201,6 +1202,14 @@ else
   UTF8PROC_INC := $(build_includedir)
 endif
 
+ifeq ($(USE_SYSTEM_ZSTD), 1)
+  LIBZSTD := -lzstd
+  ZSTD_INC := $(LOCALBASE)/include
+else
+  LIBZSTD := -L$(build_shlibdir) -lzstd
+  ZSTD_INC := $(build_includedir)
+endif
+
 # We need python for things like BB triplet recognition.  We don't really care
 # about version, generally, so just find something that works:
 PYTHON := $(shell which python 2>/dev/null || which python3 2>/dev/null || which python2 2>/dev/null || echo not found)
@@ -1268,7 +1277,7 @@ CSL_NEXT_GLIBCXX_VERSION=GLIBCXX_3\.4\.33|GLIBCXX_3\.5\.|GLIBCXX_4\.
 # Note: we explicitly _do not_ define `CSL` here, since it requires some more
 # advanced techniques to decide whether it should be installed from a BB source
 # or not.  See `deps/csl.mk` for more detail.
-BB_PROJECTS := BLASTRAMPOLINE OPENBLAS LLVM LIBSUITESPARSE OPENLIBM GMP MBEDTLS LIBSSH2 NGHTTP2 MPFR CURL LIBGIT2 PCRE LIBUV LIBUNWIND DSFMT OBJCONV ZLIB P7ZIP LLD LIBTRACYCLIENT
+BB_PROJECTS := BLASTRAMPOLINE OPENBLAS LLVM LIBSUITESPARSE OPENLIBM GMP MBEDTLS LIBSSH2 NGHTTP2 MPFR CURL LIBGIT2 PCRE LIBUV LIBUNWIND DSFMT OBJCONV ZLIB ZSTD P7ZIP LLD LIBTRACYCLIENT
 define SET_BB_DEFAULT
 # First, check to see if BB is disabled on a global setting
 ifeq ($$(USE_BINARYBUILDER),0)
diff --git a/Makefile b/Makefile
index 05683fda0a004..bdc05d75f9a2c 100644
--- a/Makefile
+++ b/Makefile
@@ -225,6 +225,7 @@ JL_PRIVATE_LIBS-$(USE_SYSTEM_ZLIB) += zlib
 else
 JL_PRIVATE_LIBS-$(USE_SYSTEM_ZLIB) += libz
 endif
+JL_PRIVATE_LIBS-$(USE_SYSTEM_ZSTD) += libzstd
 ifeq ($(USE_LLVM_SHLIB),1)
 JL_PRIVATE_LIBS-$(USE_SYSTEM_LLVM) += libLLVM $(LLVM_SHARED_LIB_NAME)
 endif
diff --git a/THIRDPARTY.md b/THIRDPARTY.md
index 412b84b688758..0b2982043d431 100644
--- a/THIRDPARTY.md
+++ b/THIRDPARTY.md
@@ -55,6 +55,7 @@ Julia bundles the following external programs and libraries:
 
 - [7-Zip](https://www.7-zip.org/license.txt)
 - [ZLIB](https://zlib.net/zlib_license.html)
+- [ZSTD](https://github.com/facebook/zstd/blob/v1.5.7/LICENSE)
 
 On some platforms, distributions of Julia contain SSL certificate authority certificates,
 released under the [Mozilla Public License](https://en.wikipedia.org/wiki/Mozilla_Public_License).
diff --git a/contrib/refresh_checksums.mk b/contrib/refresh_checksums.mk
index f67088141ccd4..506f524062538 100644
--- a/contrib/refresh_checksums.mk
+++ b/contrib/refresh_checksums.mk
@@ -24,7 +24,7 @@ CLANG_TRIPLETS=$(filter %-darwin %-freebsd,$(TRIPLETS))
 NON_CLANG_TRIPLETS=$(filter-out %-darwin %-freebsd,$(TRIPLETS))
 
 # These are the projects currently using BinaryBuilder; both GCC-expanded and non-GCC-expanded:
-BB_PROJECTS=mbedtls libssh2 nghttp2 mpfr curl libgit2 pcre libuv unwind llvmunwind dsfmt objconv p7zip zlib libsuitesparse openlibm blastrampoline libtracyclient
+BB_PROJECTS=mbedtls libssh2 nghttp2 mpfr curl libgit2 pcre libuv unwind llvmunwind dsfmt objconv p7zip zlib zstd libsuitesparse openlibm blastrampoline libtracyclient
 BB_GCC_EXPANDED_PROJECTS=openblas csl
 BB_CXX_EXPANDED_PROJECTS=gmp llvm clang llvm-tools lld
 # These are non-BB source-only deps
diff --git a/deps/Makefile b/deps/Makefile
index 6a1b03eec919e..e942262cf6f0e 100644
--- a/deps/Makefile
+++ b/deps/Makefile
@@ -70,10 +70,12 @@ endif
 endif
 endif
 
+PATCHELF_MANIFEST :=
 ifneq (,$(findstring $(OS),Linux FreeBSD))
 ifeq ($(USE_SYSTEM_PATCHELF), 0)
 DEP_LIBS += patchelf
 PATCHELF:=$(build_depsbindir)/patchelf
+PATCHELF_MANIFEST:=$(build_prefix)/manifest/patchelf
 else
 PATCHELF:=patchelf
 endif
@@ -155,6 +157,10 @@ ifeq ($(USE_SYSTEM_ZLIB), 0)
 DEP_LIBS += zlib
 endif
 
+ifeq ($(USE_SYSTEM_ZSTD), 0)
+DEP_LIBS += zstd
+endif
+
 ifeq ($(USE_SYSTEM_P7ZIP), 0)
 DEP_LIBS += p7zip
 endif
@@ -195,7 +201,7 @@ DEP_LIBS_STAGED := $(DEP_LIBS)
 # list all targets
 DEP_LIBS_STAGED_ALL := llvm llvm-tools clang llvmunwind unwind libuv pcre \
 	openlibm dsfmt blastrampoline openblas lapack gmp mpfr patchelf utf8proc \
-	objconv mbedtls libssh2 nghttp2 curl libgit2 libwhich zlib p7zip csl \
+	objconv mbedtls libssh2 nghttp2 curl libgit2 libwhich zlib zstd p7zip csl \
 	sanitizers libsuitesparse lld libtracyclient ittapi JuliaSyntax terminfo
 DEP_LIBS_ALL := $(DEP_LIBS_STAGED_ALL)
 
@@ -244,6 +250,7 @@ include $(SRCDIR)/openblas.mk
 include $(SRCDIR)/utf8proc.mk
 include $(SRCDIR)/libsuitesparse.mk
 include $(SRCDIR)/zlib.mk
+include $(SRCDIR)/zstd.mk
 include $(SRCDIR)/unwind.mk
 include $(SRCDIR)/gmp.mk
 include $(SRCDIR)/mpfr.mk
diff --git a/deps/checksums/zstd b/deps/checksums/zstd
new file mode 100644
index 0000000000000..aea151b266966
--- /dev/null
+++ b/deps/checksums/zstd
@@ -0,0 +1,38 @@
+Zstd.v1.5.7+1.aarch64-apple-darwin.tar.gz/md5/d6b2fb32d705078dbc369986ac8b056b
+Zstd.v1.5.7+1.aarch64-apple-darwin.tar.gz/sha512/5dfcf36087ce8540b1f6a04181adee962e2164a763e758ac5cc256c332756774b381ca58e26641a15ce555d59641690a6da72a67bf935d8611734f2006bde504
+Zstd.v1.5.7+1.aarch64-linux-gnu.tar.gz/md5/0c627ec83e426383c25eb4bc297f3548
+Zstd.v1.5.7+1.aarch64-linux-gnu.tar.gz/sha512/1fdcf77e877f0676fc26a05e0cc20a1d6e1df731d81e0bba9a5657131116bbea75da4d38953969d8d07dce0bf2d7654075dbb285ebe5f4588c446e88774336c8
+Zstd.v1.5.7+1.aarch64-linux-musl.tar.gz/md5/cc9ada74a19db50d7dd6edd05866c902
+Zstd.v1.5.7+1.aarch64-linux-musl.tar.gz/sha512/0b33c0df144bb1e95290685f01695b26da834a70a365c0362314cb001ba611962a0876bc5baac31f19c80bcb110e030fb9840a56761b4d29a7893ca65f95b111
+Zstd.v1.5.7+1.aarch64-unknown-freebsd.tar.gz/md5/5daa5b2bf2b856c448feaa8329d0de1b
+Zstd.v1.5.7+1.aarch64-unknown-freebsd.tar.gz/sha512/b39d025463b4bf21295fd5bbff91ba501506b3480363cdcfe6dd2f11d2e0afaf130f6c74d962e503fccb7a55bfcad0504ebb19f18b6b5c8b8103e7b9919df536
+Zstd.v1.5.7+1.armv6l-linux-gnueabihf.tar.gz/md5/f4218e8b4f8d415df49aeba9d43f0ba0
+Zstd.v1.5.7+1.armv6l-linux-gnueabihf.tar.gz/sha512/878d4f90160c6b0c341c61ecafbf5f5cb89c73db3175f272adc666bc25c88b127145d78946bc0fcb992489b54fbb48089bfcacf768397fc5d54d7cae4aeae9f9
+Zstd.v1.5.7+1.armv6l-linux-musleabihf.tar.gz/md5/3c2e132ca47e6d1d23c149fdde9d8bd5
+Zstd.v1.5.7+1.armv6l-linux-musleabihf.tar.gz/sha512/3745d99c9ca0ce9f98ff9393e405e8b382d05573a972067d57e800e282a9544fff7bc3d49b91eccc98d7736acdc3faa4c637911d79fab10f5a691d33ae775574
+Zstd.v1.5.7+1.armv7l-linux-gnueabihf.tar.gz/md5/926d765281bef388ecc25d04cbb66102
+Zstd.v1.5.7+1.armv7l-linux-gnueabihf.tar.gz/sha512/2d2c14587e2e7b2b147cb6423720cc30ed6aa57ed07372a1aa54e7f2e6badb5aa640b116e83371561d6f8f3a1b3f7fff7f6df137f8c7be788ee889bb30273eae
+Zstd.v1.5.7+1.armv7l-linux-musleabihf.tar.gz/md5/c25420561ce254e57d74e30c88fc53dd
+Zstd.v1.5.7+1.armv7l-linux-musleabihf.tar.gz/sha512/2f924e2089589057e8713d04db9a1cb2f2d571ad9e7eeda3b7f898c9a75f8fecf0647f2185d3c01fc3b399d3662ff3b1acb13429c8a953f0394a3ed9ca30b877
+Zstd.v1.5.7+1.i686-linux-gnu.tar.gz/md5/3314bf1b52f2295555fb4ae44b1d9331
+Zstd.v1.5.7+1.i686-linux-gnu.tar.gz/sha512/91502910a0c9b786d91499477fee2445b8f6de6bcb71af7d79c738ea2430c67cb1957866383ee3921ed1a23c53a80be19aea6abcf0e76056ffee69583728c3ed
+Zstd.v1.5.7+1.i686-linux-musl.tar.gz/md5/845eddc06527a4c4b196666f7ac64ba3
+Zstd.v1.5.7+1.i686-linux-musl.tar.gz/sha512/bb15b4327cef32be38c2fd68afedb3245c7db881ad66d3ece2198ff3034be9c12efa3d62bcba2b8e6056e7d8cb5f1b3e33726f7d1e1bead235c38f8fa985b557
+Zstd.v1.5.7+1.i686-w64-mingw32.tar.gz/md5/9bc0b3c951f5e66393fd5433bf60a2c8
+Zstd.v1.5.7+1.i686-w64-mingw32.tar.gz/sha512/550b0189097e569f98404aa836b76a5cbdc36428292214c4af8916dea2713440cf3ba94125b3e5fa0c65b2bcb916733094fdef906ad19f923d90dabfc961c75a
+Zstd.v1.5.7+1.powerpc64le-linux-gnu.tar.gz/md5/468d930de7a27af961996e7c6ed35298
+Zstd.v1.5.7+1.powerpc64le-linux-gnu.tar.gz/sha512/d680715b1ac9ff07d5662c499fbab67757509599335f861158b9dba32fe9b22da6e52d0db6b402dd4542799621ad3dccf254dfd9d3c8748bbd22f7446681539a
+Zstd.v1.5.7+1.riscv64-linux-gnu.tar.gz/md5/b93fef8db2b0b4417f7836d73c5fbe86
+Zstd.v1.5.7+1.riscv64-linux-gnu.tar.gz/sha512/9f3ee42c7952aba2d2c26252f058bb7ab96828fafc978c9273b500ef15ccd271c51399d4b93eebd4c832b087ab5ed8a4847104ce9c83c9483aaa13c22df681bb
+Zstd.v1.5.7+1.x86_64-apple-darwin.tar.gz/md5/29a260789fae6f6b6df0e5cebdafd615
+Zstd.v1.5.7+1.x86_64-apple-darwin.tar.gz/sha512/015045a1b7a477504057cb4c87428d42386218e48af38f83739dbe6b93961ca2c8dd4d794377a2d54b8cc284f5a467e3358d4f534cf8bcbcad886ef8cea038e9
+Zstd.v1.5.7+1.x86_64-linux-gnu.tar.gz/md5/06656befb6ef9a8cc7f56e7152c2acc5
+Zstd.v1.5.7+1.x86_64-linux-gnu.tar.gz/sha512/16aea0d95432a87d21d9a6f55d84e45df85caf1fda77c75b7e9a8bba519605168585f21a812773ddf1075d9bad68412e63b8cad1a143420e25ae4405bb41842e
+Zstd.v1.5.7+1.x86_64-linux-musl.tar.gz/md5/da13dd1cc0d20ba9a06e9e79a588cda4
+Zstd.v1.5.7+1.x86_64-linux-musl.tar.gz/sha512/cd4218fa92dcf8772390788d5654ca12132af7829fb0ada016f3c663e2045e29e7d7587f2f5a4f057020cacca17c188c8537f284b1456100d57e84bb47c40e77
+Zstd.v1.5.7+1.x86_64-unknown-freebsd.tar.gz/md5/bce5f37e53e330bfe4df4a28cf5c223b
+Zstd.v1.5.7+1.x86_64-unknown-freebsd.tar.gz/sha512/8f6bd7664efea537ac7815db0604ca1a07bcfb71b5152c22dc7f0a11b57643f059c341fa71d315407e2333e4c97e43e214471c73eed8b977680785302c7c2b3e
+Zstd.v1.5.7+1.x86_64-w64-mingw32.tar.gz/md5/7cf3a740fa174004b94125e8754f4a19
+Zstd.v1.5.7+1.x86_64-w64-mingw32.tar.gz/sha512/faac37ad4dacb0f083364c593cd3bd1c0b592947341a631bd2fbc4081361d97ef89482f4459c46ad37ae030aa900c62305a8525e64a2ad8e91204d76dda89db1
+zstd-f8745da6ff1ad1e7bab384bd1f9d742439278e99.tar.gz/md5/a679d9aa86549b5851100ac5d4044c68
+zstd-f8745da6ff1ad1e7bab384bd1f9d742439278e99.tar.gz/sha512/27c6fff165abea694d91311a6657a939433ba1d707147ed9072b5e4ecce259b929970306788e0c3e95db38ce85e894e5025936b1faa81cf67741b8464e24fc4e
diff --git a/deps/zstd.mk b/deps/zstd.mk
new file mode 100644
index 0000000000000..5ead77641858a
--- /dev/null
+++ b/deps/zstd.mk
@@ -0,0 +1,60 @@
+## Zstd ##
+ifneq ($(USE_BINARYBUILDER_ZSTD), 1)
+ZSTD_GIT_URL := https://github.com/facebook/zstd.git
+ZSTD_TAR_URL = https://api.github.com/repos/facebook/zstd/tarball/$1
+$(eval $(call git-external,zstd,ZSTD,,,$(BUILDDIR)))
+
+ZSTD_BUILD_OPTS := MOREFLAGS="-DZSTD_MULTITHREAD $(fPIC)" bindir=$(build_private_libexecdir)
+
+$(BUILDDIR)/$(ZSTD_SRC_DIR)/build-configured: $(BUILDDIR)/$(ZSTD_SRC_DIR)/source-extracted
+	echo 1 > $@
+
+$(BUILDDIR)/$(ZSTD_SRC_DIR)/build-compiled: $(BUILDDIR)/$(ZSTD_SRC_DIR)/build-configured
+	$(MAKE) -C $(dir $<) $(MAKE_COMMON) $(ZSTD_BUILD_OPTS)
+	echo 1 > $@
+
+$(eval $(call staged-install, \
+	zstd,$(ZSTD_SRC_DIR), \
+	MAKE_INSTALL,$(ZSTD_BUILD_OPTS) MT=1,, \
+	$(INSTALL_NAME_CMD)libzstd.$(SHLIB_EXT) $(build_private_libexecdir)/libzstd.$(SHLIB_EXT)))
+
+clean-zstd:
+	-rm -f $(BUILDDIR)/$(ZSTD_SRC_DIR)/build-configured $(BUILDDIR)/$(ZSTD_SRC_DIR)/build-compiled
+	-$(MAKE) -C $(BUILDDIR)/$(ZSTD_SRC_DIR) $(MAKE_COMMON) $(ZSTD_BUILD_OPTS) clean
+
+get-zstd: $(ZSTD_SRC_FILE)
+extract-zstd: $(BUILDDIR)/$(ZSTD_SRC_DIR)/source-extracted
+configure-zstd: $(BUILDDIR)/$(ZSTD_SRC_DIR)/build-configured
+compile-zstd: $(BUILDDIR)/$(ZSTD_SRC_DIR)/build-compiled
+fastcheck-zstd: check-zstd
+check-zstd: compile-zstd
+
+else # USE_BINARYBUILDER_ZSTD
+
+$(eval $(call bb-install,zstd,ZSTD,false))
+# move from bindir to shlibdir, where we expect to install it
+install-zstd: post-install-zstd
+uninstall-zstd: pre-uninstall-zstd
+post-install-zstd: $(build_prefix)/manifest/zstd $(PATCHELF_MANIFEST)
+	mkdir -p $(build_private_libexecdir)/
+	[ ! -e $(build_bindir)/zstdmt$(EXE) ] || mv $(build_bindir)/zstdmt$(EXE) $(build_private_libexecdir)/zstdmt$(EXE)
+	[ ! -e $(build_bindir)/zstd$(EXE) ] || mv $(build_bindir)/zstd$(EXE) $(build_private_libexecdir)/zstd$(EXE)
+	[ -e $(build_private_libexecdir)/zstd$(EXE) ]
+	[ -e $(build_private_libexecdir)/zstdmt$(EXE) ]
+ifeq ($(OS), Darwin)
+	for j in zstd zstdmt ; do \
+		[ -L $(build_private_libexecdir)/$$j ] && continue; \
+		install_name_tool -rpath @executable_path/$(reverse_build_private_libexecdir_rel) @loader_path/$(build_libdir_rel) $(build_private_libexecdir)/$$j 2>/dev/null || true; \
+		install_name_tool -rpath @loader_path/$(build_libdir_rel) @executable_path/$(reverse_build_private_libexecdir_rel) $(build_private_libexecdir)/$$j || exit 1; \
+	done
+else ifneq (,$(findstring $(OS),Linux FreeBSD))
+	for j in zstd zstdmt ; do \
+		[ -L $(build_private_libexecdir)/$$j ] && continue; \
+		$(PATCHELF) $(PATCHELF_SET_RPATH_ARG) '$$ORIGIN/$(reverse_build_private_libexecdir_rel)' $(build_private_libexecdir)/$$j || exit 1; \
+	done
+endif
+
+pre-uninstall-zstd:
+	-rm -f $(build_private_libexecdir)/zstd$(EXE) $(build_private_libexecdir)/zstdmt$(EXE)
+
+endif # USE_BINARYBUILDER_ZSTD
diff --git a/deps/zstd.version b/deps/zstd.version
new file mode 100644
index 0000000000000..d4d960aa6f04b
--- /dev/null
+++ b/deps/zstd.version
@@ -0,0 +1,8 @@
+# -*- makefile -*-
+## jll artifact
+ZSTD_JLL_NAME := Zstd
+
+## source build
+ZSTD_VER := 1.5.7
+ZSTD_BRANCH=v1.5.7
+ZSTD_SHA1=f8745da6ff1ad1e7bab384bd1f9d742439278e99
diff --git a/julia.spdx.json b/julia.spdx.json
index 63683dd302a39..21d07c68560a0 100644
--- a/julia.spdx.json
+++ b/julia.spdx.json
@@ -420,6 +420,18 @@
             "copyrightText": "Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler",
             "summary": "A massively spiffy yet delicately unobtrusive compression library."
         },
+        {
+            "name": "zstd",
+            "SPDXID": "SPDXRef-zstd",
+            "downloadLocation": "git+https://github.com/facebook/zstd.git",
+            "filesAnalyzed": false,
+            "homepage": "https://www.zstd.net",
+            "sourceInfo": "The git hash of the version in use can be found in the file deps/zstd.version",
+            "licenseConcluded": "BSD-3-Clause",
+            "licenseDeclared": "GPL-2.0+ OR BSD-3-Clause",
+            "copyrightText": "Copyright (c) Meta Platforms, Inc. and affiliates. All rights reserved.",
+            "summary": "Zstandard, or zstd as short version, is a fast lossless compression algorithm."
+        },
         {
             "name": "patchelf",
             "SPDXID": "SPDXRef-patchelf",
@@ -627,6 +639,11 @@
             "relationshipType": "BUILD_DEPENDENCY_OF",
             "relatedSpdxElement": "SPDXRef-JuliaMain"
         },
+        {
+            "spdxElementId": "SPDXRef-zstd",
+            "relationshipType": "BUILD_DEPENDENCY_OF",
+            "relatedSpdxElement": "SPDXRef-JuliaMain"
+        },
         {
             "spdxElementId": "SPDXRef-patchelf",
             "relationshipType": "BUILD_TOOL_OF",
diff --git a/src/Makefile b/src/Makefile
index c25649d2cab7c..c2ff0b0f6b296 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -17,7 +17,8 @@ FLAGS := \
 	-D_GNU_SOURCE -I$(BUILDDIR) -I$(SRCDIR) \
 	-I$(SRCDIR)/flisp -I$(SRCDIR)/support \
 	-I$(LIBUV_INC) -I$(build_includedir) \
-	-I$(JULIAHOME)/deps/valgrind
+	-I$(JULIAHOME)/deps/valgrind \
+	-I$(ZSTD_INC)
 FLAGS += -Wall -Wno-strict-aliasing -fno-omit-frame-pointer -fvisibility=hidden -fno-common \
 		 -Wno-comment -Wpointer-arith -Wundef
 ifeq ($(USEGCC),1) # GCC bug #25509 (void)__attribute__((warn_unused_result))
@@ -169,7 +170,7 @@ LIBJULIA_PATH_REL := libjulia
 endif
 
 COMMON_LIBPATHS := -L$(build_libdir) -L$(build_shlibdir)
-RT_LIBS := $(WHOLE_ARCHIVE) $(LIBUV) $(WHOLE_ARCHIVE) $(LIBUTF8PROC) $(NO_WHOLE_ARCHIVE) $(LIBUNWIND) $(RT_LLVMLINK) $(OSLIBS) $(LIBTRACYCLIENT) $(LIBITTAPI)
+RT_LIBS := $(WHOLE_ARCHIVE) $(LIBUV) $(WHOLE_ARCHIVE) $(LIBUTF8PROC) $(NO_WHOLE_ARCHIVE) $(LIBUNWIND) $(RT_LLVMLINK) $(OSLIBS) $(LIBTRACYCLIENT) $(LIBITTAPI) $(LIBZSTD)
 CG_LIBS := $(LIBUNWIND) $(CG_LLVMLINK) $(OSLIBS) $(LIBTRACYCLIENT) $(LIBITTAPI)
 RT_DEBUG_LIBS := $(COMMON_LIBPATHS) $(WHOLE_ARCHIVE) $(BUILDDIR)/flisp/libflisp-debug.a $(WHOLE_ARCHIVE) $(BUILDDIR)/support/libsupport-debug.a -ljulia-debug $(RT_LIBS)
 CG_DEBUG_LIBS := $(COMMON_LIBPATHS) $(CG_LIBS) -ljulia-debug -ljulia-internal-debug
diff --git a/stdlib/Makefile b/stdlib/Makefile
index d478d2ad4c188..eb08979987f75 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -19,7 +19,7 @@ $(foreach dir,$(DIRS),$(eval $(call dir_target,$(dir))))
 
 JLLS = DSFMT GMP CURL LIBGIT2 LLVM LIBSSH2 LIBUV MBEDTLS MPFR NGHTTP2 \
        BLASTRAMPOLINE OPENBLAS OPENLIBM P7ZIP PCRE LIBSUITESPARSE ZLIB \
-       LLVMUNWIND CSL UNWIND LLD
+       ZSTD LLVMUNWIND CSL UNWIND LLD
 
 # Initialize this with JLLs that aren't in "deps/$(LibName).version"
 JLL_NAMES := MozillaCACerts_jll
diff --git a/stdlib/Manifest.toml b/stdlib/Manifest.toml
index 5ad675ac21510..489baa7b9732d 100644
--- a/stdlib/Manifest.toml
+++ b/stdlib/Manifest.toml
@@ -268,6 +268,11 @@ deps = ["Libdl"]
 uuid = "83775a58-1f1d-513f-b197-d71354ab007a"
 version = "1.2.13+1"
 
+[[deps.Zstd_jll]]
+deps = ["Libdl"]
+uuid = "3161d3a3-bdf6-5164-811a-617609db77b4"
+version = "1.5.7+1"
+
 [[deps.dSFMT_jll]]
 deps = ["Artifacts", "Libdl"]
 uuid = "05ff407c-b0c1-5878-9df8-858cc2e60c36"
diff --git a/stdlib/Zstd_jll/Project.toml b/stdlib/Zstd_jll/Project.toml
new file mode 100644
index 0000000000000..467516843390a
--- /dev/null
+++ b/stdlib/Zstd_jll/Project.toml
@@ -0,0 +1,15 @@
+name = "Zstd_jll"
+uuid = "3161d3a3-bdf6-5164-811a-617609db77b4"
+version = "1.5.7+1"
+
+[deps]
+Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+
+[compat]
+julia = "1.6"
+
+[extras]
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Test"]
diff --git a/stdlib/Zstd_jll/src/Zstd_jll.jl b/stdlib/Zstd_jll/src/Zstd_jll.jl
new file mode 100644
index 0000000000000..c16413f963d0b
--- /dev/null
+++ b/stdlib/Zstd_jll/src/Zstd_jll.jl
@@ -0,0 +1,73 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+## dummy stub for https://github.com/JuliaBinaryWrappers/Zstd_jll.j:
+#
+baremodule Zstd_jll
+using Base, Libdl
+
+export libzstd, zstd, zstdmt
+
+# These get calculated in __init__()
+libzstd_handle::Ptr{Cvoid} = C_NULL
+
+if Sys.iswindows()
+    const libzstd = "libzstd-1.dll"
+elseif Sys.isapple()
+    const libzstd = "@rpath/libzstd.1.dylib"
+else
+    const libzstd = "libzstd.so.1"
+end
+
+if Sys.iswindows()
+    const zstd_exe = "zstd.exe"
+    const zstdmt_exe = "zstdmt.exe"
+else
+    const zstd_exe = "zstd"
+    const zstdmt_exe = "zstdmt"
+end
+
+if Sys.iswindows()
+    const pathsep = ';'
+elseif Sys.isapple()
+    const pathsep = ':'
+else
+    const pathsep = ':'
+end
+
+if Sys.iswindows()
+function adjust_ENV(cmd::Cmd)
+    dllPATH = Sys.BINDIR
+    oldPATH = get(ENV, "PATH", "")
+    newPATH = isempty(oldPATH) ? dllPATH : "$dllPATH$pathsep$oldPATH"
+    return addenv(cmd, "PATH"=>newPATH)
+end
+else
+adjust_ENV(cmd::Cmd) = cmd
+end
+
+function adjust_ENV()
+    addPATH = joinpath(Sys.BINDIR, Base.PRIVATE_LIBEXECDIR)
+    oldPATH = get(ENV, "PATH", "")
+    newPATH = isempty(oldPATH) ? addPATH : "$addPATH$pathsep$oldPATH"
+    return ("PATH"=>newPATH,)
+end
+
+function zstd(f::Function; adjust_PATH::Bool = true, adjust_LIBPATH::Bool = true) # deprecated, for compat only
+    withenv((adjust_PATH ? adjust_ENV() : ())...) do
+        f(zstd())
+    end
+end
+function zstdmt(f::Function; adjust_PATH::Bool = true, adjust_LIBPATH::Bool = true) # deprecated, for compat only
+    withenv((adjust_PATH ? adjust_ENV() : ())...) do
+        f(zstdmt())
+    end
+end
+zstd() = adjust_ENV(`$(joinpath(Sys.BINDIR, Base.PRIVATE_LIBEXECDIR, zstd_exe))`)
+zstdmt() = adjust_ENV(`$(joinpath(Sys.BINDIR, Base.PRIVATE_LIBEXECDIR, zstdmt_exe))`)
+
+function __init__()
+    global libzstd_handle = dlopen(libzstd)
+    nothing
+end
+
+end  # module Zstd_jll
diff --git a/stdlib/Zstd_jll/test/runtests.jl b/stdlib/Zstd_jll/test/runtests.jl
new file mode 100644
index 0000000000000..5cfa2a1375c73
--- /dev/null
+++ b/stdlib/Zstd_jll/test/runtests.jl
@@ -0,0 +1,7 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+using Test, Zstd_jll
+
+@testset "Zstd_jll" begin
+    @test ccall((:ZSTD_versionNumber, libzstd), Cuint, ()) == 1_05_07
+end
diff --git a/stdlib/stdlib.mk b/stdlib/stdlib.mk
index 021639ec0bad0..9670fe49bc0fe 100644
--- a/stdlib/stdlib.mk
+++ b/stdlib/stdlib.mk
@@ -9,7 +9,7 @@ INDEPENDENT_STDLIBS := \
 	SparseArrays Statistics StyledStrings SuiteSparse_jll Tar Test TOML Unicode UUIDs \
 	dSFMT_jll GMP_jll libLLVM_jll LLD_jll LLVMLibUnwind_jll LibUnwind_jll LibUV_jll \
 	LibCURL_jll LibSSH2_jll LibGit2_jll nghttp2_jll  MozillaCACerts_jll MbedTLS_jll \
-	MPFR_jll OpenLibm_jll PCRE2_jll p7zip_jll Zlib_jll
+	MPFR_jll OpenLibm_jll PCRE2_jll p7zip_jll Zlib_jll Zstd_jll
 
 STDLIBS := $(STDLIBS_WITHIN_SYSIMG) $(INDEPENDENT_STDLIBS)
 VERSDIR := v$(shell cut -d. -f1-2 < $(JULIAHOME)/VERSION)

From 5c227a2484ab96c0ab310fd45529872928b08da1 Mon Sep 17 00:00:00 2001
From: Sam Schweigel <sam.schweigel@juliahub.com>
Date: Wed, 6 Aug 2025 16:35:34 -0700
Subject: [PATCH 4/6] System image compression with zstd

Co-authored-by: Gabriel Baraldi <baraldigabriel@gmail.com>

madvise with MADV_WILLNEED before accessing sysimage pages

MADV_WILLNEED sysimage pages before checksumming or decompressing

Even without compression, this gives about an 8% improvement in load times.

Fix using jl_page_size before it is initialized

Add zstd to ANALYSIS_DEPS now that it is used in staticdata.c

Fix jl_page_size being uninitialized in jl_prefetch_system_image

Add --compress-sysimage flag; use zstd-15 when enabled
---
 Make.inc           |   2 +-
 base/options.jl    |   1 +
 base/util.jl       |   3 ++
 src/Makefile       |   4 +-
 src/aotcompile.cpp |  45 +++++++++++++----
 src/jloptions.c    |  22 +++++++--
 src/jloptions.h    |   1 +
 src/staticdata.c   | 117 +++++++++++++++++++++++++++++++++++----------
 8 files changed, 154 insertions(+), 41 deletions(-)

diff --git a/Make.inc b/Make.inc
index b45886c2af963..1685142e691a8 100644
--- a/Make.inc
+++ b/Make.inc
@@ -1406,7 +1406,7 @@ JLDFLAGS += -Wl,--stack,8388608 --disable-auto-import --disable-runtime-pseudo-r
 ifeq ($(ARCH),i686)
 JLDFLAGS += -Wl,--large-address-aware
 endif
-JCPPFLAGS += -D_WIN32_WINNT=0x0502
+JCPPFLAGS += -D_WIN32_WINNT=_WIN32_WINNT_WIN8
 UNTRUSTED_SYSTEM_LIBM := 1
 # Use hard links for files on windows, rather than soft links
 #   https://stackoverflow.com/questions/3648819/how-to-make-a-symbolic-link-with-cygwin-in-windows-7
diff --git a/base/options.jl b/base/options.jl
index 18fa2ad92654d..0465947801223 100644
--- a/base/options.jl
+++ b/base/options.jl
@@ -58,6 +58,7 @@ struct JLOptions
     strip_ir::Int8
     permalloc_pkgimg::Int8
     heap_size_hint::UInt64
+    compress_sysimage::Int8
 end
 
 # This runs early in the sysimage != is not defined yet
diff --git a/base/util.jl b/base/util.jl
index 3a621211162ec..f233e6f1d234d 100644
--- a/base/util.jl
+++ b/base/util.jl
@@ -245,6 +245,9 @@ function julia_cmd(julia=joinpath(Sys.BINDIR, julia_exename()); cpu_target::Unio
     if opts.use_sysimage_native_code == 0
         push!(addflags, "--sysimage-native-code=no")
     end
+    if opts.compress_sysimage == 1
+        push!(addflags, "--compress-sysimage=yes")
+    end
     return `$julia -C $cpu_target -J$image_file $addflags`
 end
 
diff --git a/src/Makefile b/src/Makefile
index c2ff0b0f6b296..d1cfe867431fc 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -171,7 +171,7 @@ endif
 
 COMMON_LIBPATHS := -L$(build_libdir) -L$(build_shlibdir)
 RT_LIBS := $(WHOLE_ARCHIVE) $(LIBUV) $(WHOLE_ARCHIVE) $(LIBUTF8PROC) $(NO_WHOLE_ARCHIVE) $(LIBUNWIND) $(RT_LLVMLINK) $(OSLIBS) $(LIBTRACYCLIENT) $(LIBITTAPI) $(LIBZSTD)
-CG_LIBS := $(LIBUNWIND) $(CG_LLVMLINK) $(OSLIBS) $(LIBTRACYCLIENT) $(LIBITTAPI)
+CG_LIBS := $(LIBUNWIND) $(CG_LLVMLINK) $(OSLIBS) $(LIBTRACYCLIENT) $(LIBITTAPI) $(LIBZSTD)
 RT_DEBUG_LIBS := $(COMMON_LIBPATHS) $(WHOLE_ARCHIVE) $(BUILDDIR)/flisp/libflisp-debug.a $(WHOLE_ARCHIVE) $(BUILDDIR)/support/libsupport-debug.a -ljulia-debug $(RT_LIBS)
 CG_DEBUG_LIBS := $(COMMON_LIBPATHS) $(CG_LIBS) -ljulia-debug -ljulia-internal-debug
 RT_RELEASE_LIBS := $(COMMON_LIBPATHS) $(WHOLE_ARCHIVE) $(BUILDDIR)/flisp/libflisp.a $(WHOLE_ARCHIVE) $(BUILDDIR)/support/libsupport.a -ljulia $(RT_LIBS)
@@ -474,7 +474,7 @@ $(build_shlibdir)/lib%Plugin.$(SHLIB_EXT): $(SRCDIR)/clangsa/%.cpp $(LLVM_CONFIG
 # before attempting this static analysis, so that all necessary headers
 # and dependencies are properly installed:
 #   make -C src install-analysis-deps
-ANALYSIS_DEPS := llvm clang llvm-tools libuv utf8proc
+ANALYSIS_DEPS := llvm clang llvm-tools libuv utf8proc zstd
 ifeq ($(OS),Darwin)
 ANALYSIS_DEPS += llvmunwind
 else ifneq ($(OS),WINNT)
diff --git a/src/aotcompile.cpp b/src/aotcompile.cpp
index 05853828d36ce..8132628b5d370 100644
--- a/src/aotcompile.cpp
+++ b/src/aotcompile.cpp
@@ -57,9 +57,10 @@
 #include <llvm/Support/FormatAdapters.h>
 #include <llvm/Linker/Linker.h>
 
-
 using namespace llvm;
 
+#include <zstd.h>
+
 #include "jitlayers.h"
 #include "serialize.h"
 #include "julia_assert.h"
@@ -1659,12 +1660,25 @@ void jl_dump_native_impl(void *native_code,
         sysimgM.setDataLayout(DL);
         sysimgM.setStackProtectorGuard(StackProtectorGuard);
         sysimgM.setOverrideStackAlignment(OverrideStackAlignment);
-        Constant *data = ConstantDataArray::get(Context,
-            ArrayRef<uint8_t>((const unsigned char*)z->buf, z->size));
+
+        int compression = jl_options.compress_sysimage ? 15 : 0;
+        ArrayRef<char> sysimg_data{z->buf, (size_t)z->size};
+        SmallVector<char, 0> compressed_data;
+        if (compression) {
+            compressed_data.resize(ZSTD_compressBound(z->size));
+            size_t comp_size = ZSTD_compress(compressed_data.data(), compressed_data.size(),
+                                             z->buf, z->size, compression);
+            compressed_data.resize(comp_size);
+            sysimg_data = compressed_data;
+            ios_close(z);
+            free(z);
+        }
+
+        Constant *data = ConstantDataArray::get(Context, sysimg_data);
         auto sysdata = new GlobalVariable(sysimgM, data->getType(), false,
                                      GlobalVariable::ExternalLinkage,
                                      data, "jl_system_image_data");
-        sysdata->setAlignment(Align(64));
+        sysdata->setAlignment(Align(jl_page_size));
 #if JL_LLVM_VERSION >= 180000
         sysdata->setCodeModel(CodeModel::Large);
 #else
@@ -1672,14 +1686,27 @@ void jl_dump_native_impl(void *native_code,
             sysdata->setSection(".ldata");
 #endif
         addComdat(sysdata, TheTriple);
-        Constant *len = ConstantInt::get(sysimgM.getDataLayout().getIntPtrType(Context), z->size);
+        Constant *len = ConstantInt::get(sysimgM.getDataLayout().getIntPtrType(Context), sysimg_data.size());
         addComdat(new GlobalVariable(sysimgM, len->getType(), true,
                                      GlobalVariable::ExternalLinkage,
                                      len, "jl_system_image_size"), TheTriple);
-        // Free z here, since we've copied out everything into data
-        // Results in serious memory savings
-        ios_close(z);
-        free(z);
+
+        const char *unpack_func = compression ? "jl_image_unpack_zstd" : "jl_image_unpack_uncomp";
+        auto unpack = new GlobalVariable(sysimgM, DL.getIntPtrType(Context), true,
+                                         GlobalVariable::ExternalLinkage, nullptr,
+                                         unpack_func);
+        addComdat(new GlobalVariable(sysimgM, PointerType::getUnqual(Context), true,
+                                     GlobalVariable::ExternalLinkage, unpack,
+                                     "jl_image_unpack"),
+                  TheTriple);
+
+        if (!compression) {
+            // Free z here, since we've copied out everything into data
+            // Results in serious memory savings
+            ios_close(z);
+            free(z);
+        }
+        compressed_data.clear();
         // Note that we don't set z to null, this allows the check in WRITE_ARCHIVE
         // to function as expected
         // no need to free the module/context, destructor handles that
diff --git a/src/jloptions.c b/src/jloptions.c
index ad13151703531..2b1c0d40005e6 100644
--- a/src/jloptions.c
+++ b/src/jloptions.c
@@ -101,6 +101,7 @@ JL_DLLEXPORT void jl_init_options(void)
                         0, // strip-ir
                         0, // permalloc_pkgimg
                         0, // heap-size-hint
+                        0, // compress_sysimage
     };
     jl_options_initialized = 1;
 }
@@ -222,10 +223,13 @@ static const char opts_hidden[]  =
     "                          Enable or disable JIT compiler, or request exhaustive or minimal compilation\n\n"
 
     // compiler output options
-    " --output-o <name>        Generate an object file (including system image data)\n"
-    " --output-ji <name>       Generate a system image data file (.ji)\n"
-    " --strip-metadata         Remove docstrings and source location info from system image\n"
-    " --strip-ir               Remove IR (intermediate representation) of compiled functions\n\n"
+    " --output-o <name>              Generate an object file (including system image data)\n"
+    " --output-ji <name>             Generate a system image data file (.ji)\n"
+    " --strip-metadata               Remove docstrings and source location info from system image\n"
+    " --strip-ir                     Remove IR (intermediate representation) of compiled functions\n"
+    " --compress-sysimage={yes|no*}  Compress the sys/pkgimage heap at the expense of\n"
+    "                                slightly increased load time.\n"
+    "\n"
 
     // compiler debugging (see the devdocs for tips on using these options)
     " --output-unopt-bc <name> Generate unoptimized LLVM bitcode (.bc)\n"
@@ -282,7 +286,8 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
            opt_strip_ir,
            opt_heap_size_hint,
            opt_gc_threads,
-           opt_permalloc_pkgimg
+           opt_permalloc_pkgimg,
+           opt_compress_sysimage,
     };
     static const char* const shortopts = "+vhqH:e:E:L:J:C:it:p:O:g:";
     static const struct option longopts[] = {
@@ -344,6 +349,7 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
         { "strip-ir",        no_argument,       0, opt_strip_ir },
         { "permalloc-pkgimg",required_argument, 0, opt_permalloc_pkgimg },
         { "heap-size-hint",  required_argument, 0, opt_heap_size_hint },
+        { "compress-sysimage", required_argument, 0, opt_compress_sysimage },
         { 0, 0, 0, 0 }
     };
 
@@ -895,6 +901,12 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
             else
                 jl_errorf("julia: invalid argument to --permalloc-pkgimg={yes|no} (%s)", optarg);
             break;
+        case opt_compress_sysimage:
+            if (!strcmp(optarg,"yes"))
+                jl_options.compress_sysimage = 1;
+            else if (!strcmp(optarg,"no"))
+                jl_options.compress_sysimage = 0;
+            break;
         default:
             jl_errorf("julia: unhandled option -- %c\n"
                       "This is a bug, please report it.", c);
diff --git a/src/jloptions.h b/src/jloptions.h
index f72e72b462066..ca938aa3fb503 100644
--- a/src/jloptions.h
+++ b/src/jloptions.h
@@ -62,6 +62,7 @@ typedef struct {
     int8_t strip_ir;
     int8_t permalloc_pkgimg;
     uint64_t heap_size_hint;
+    int8_t compress_sysimage;
 } jl_options_t;
 
 #endif
diff --git a/src/staticdata.c b/src/staticdata.c
index 3376933eed038..10790422f0539 100644
--- a/src/staticdata.c
+++ b/src/staticdata.c
@@ -74,6 +74,8 @@ External links:
 #include <stdio.h> // printf
 #include <inttypes.h> // PRIxPTR
 
+#include <zstd.h>
+
 #include "julia.h"
 #include "julia_internal.h"
 #include "julia_gcext.h"
@@ -81,8 +83,11 @@ External links:
 #include "processor.h"
 #include "serialize.h"
 
-#ifndef _OS_WINDOWS_
+#ifdef _OS_WINDOWS_
+#include <memoryapi.h>
+#else
 #include <dlfcn.h>
+#include <sys/mman.h>
 #endif
 
 #include "valgrind.h"
@@ -3080,14 +3085,75 @@ JL_DLLEXPORT jl_image_buf_t jl_preload_sysimg(const char *fname)
     }
 }
 
-// From a shared library handle, verify consistency and return a jl_image_buf_t
-static jl_image_buf_t get_image_buf(void *handle, int is_pkgimage)
+typedef void jl_image_unpack_func_t(void *handle, jl_image_buf_t *image);
+
+static void jl_prefetch_system_image(const char *data, size_t size)
+{
+    size_t page_size = jl_getpagesize(); /* jl_page_size is not set yet when loading sysimg */
+    void *start = (void *)((uintptr_t)data & ~(page_size - 1));
+    size_t size_aligned = LLT_ALIGN(size, page_size);
+#ifdef _OS_WINDOWS_
+    WIN32_MEMORY_RANGE_ENTRY entry = {start, size_aligned};
+    PrefetchVirtualMemory(GetCurrentProcess(), 1, &entry, 0);
+#else
+    madvise(start, size_aligned, MADV_WILLNEED);
+#endif
+}
+
+JL_DLLEXPORT void jl_image_unpack_uncomp(void *handle, jl_image_buf_t *image)
+{
+    size_t *plen;
+    jl_dlsym(handle, "jl_system_image_size", (void **)&plen, 1);
+    jl_dlsym(handle, "jl_system_image_data", (void **)&image->data, 1);
+    jl_dlsym(handle, "jl_image_pointers", (void**)&image->pointers, 1);
+    image->size = *plen;
+    jl_prefetch_system_image(image->data, image->size);
+}
+
+JL_DLLEXPORT void jl_image_unpack_zstd(void *handle, jl_image_buf_t *image)
 {
     size_t *plen;
     const char *data;
-    const void *pointers;
-    uint64_t base;
+    jl_dlsym(handle, "jl_system_image_size", (void **)&plen, 1);
+    jl_dlsym(handle, "jl_system_image_data", (void **)&data, 1);
+    jl_dlsym(handle, "jl_image_pointers", (void **)&image->pointers, 1);
+    jl_prefetch_system_image(data, *plen);
+    image->size = ZSTD_getFrameContentSize(data, *plen);
+    size_t page_size = jl_getpagesize(); /* jl_page_size is not set yet when loading sysimg */
+    size_t aligned_size = LLT_ALIGN(image->size, page_size);
+#if defined(_OS_WINDOWS_)
+    size_t large_page_size = GetLargePageMinimum();
+    if (image->size > 4 * large_page_size) {
+        size_t aligned_size = LLT_ALIGN(image->size, large_page_size);
+        image->data = (char *)VirtualAlloc(
+            NULL, aligned_size, MEM_COMMIT | MEM_RESERVE | MEM_LARGE_PAGES, PAGE_READWRITE);
+    }
+    else {
+        image->data = (char *)VirtualAlloc(NULL, aligned_size, MEM_COMMIT | MEM_RESERVE,
+                                           PAGE_READWRITE);
+    }
+#else
+    image->data =
+        (char *)mmap(NULL, aligned_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#endif
+    if (!image->data || image->data == (void *)-1) {
+        jl_printf(JL_STDERR, "ERROR: failed to allocate space for system image\n");
+        jl_exit(1);
+    }
+
+    ZSTD_decompress((void *)image->data, image->size, data, *plen);
+    size_t len = (*plen) & ~(page_size - 1);
+#ifdef _OS_WINDOWS_
+    if (len)
+        VirtualFree((void *)data, len, MEM_RELEASE);
+#else
+    munmap((void *)data, len);
+#endif
+}
 
+// From a shared library handle, verify consistency and return a jl_image_buf_t
+static jl_image_buf_t get_image_buf(void *handle, int is_pkgimage)
+{
     // verify that the linker resolved the symbols in this image against ourselves (libjulia-internal)
     void** (*get_jl_RTLD_DEFAULT_handle_addr)(void) = NULL;
     if (handle != jl_RTLD_DEFAULT_handle) {
@@ -3096,39 +3162,42 @@ static jl_image_buf_t get_image_buf(void *handle, int is_pkgimage)
             jl_error("Image file failed consistency check: maybe opened the wrong version?");
     }
 
+    jl_image_unpack_func_t **unpack;
+    jl_image_buf_t image = {
+        .kind = JL_IMAGE_KIND_SO,
+        .handle = handle,
+        .pointers = NULL,
+        .data = NULL,
+        .size = 0,
+        .base = 0,
+    };
+
     // verification passed, lookup the buffer pointers
     if (jl_system_image_size == 0 || is_pkgimage) {
         // in the usual case, the sysimage was not statically linked to libjulia-internal
         // look up the external sysimage symbols via the dynamic linker
-        jl_dlsym(handle, "jl_system_image_size", (void **)&plen, 1);
-        jl_dlsym(handle, "jl_system_image_data", (void **)&data, 1);
-        jl_dlsym(handle, "jl_image_pointers", (void**)&pointers, 1);
-    } else {
+        jl_dlsym(handle, "jl_image_unpack", (void **)&unpack, 1);
+        (*unpack)(handle, &image);
+    }
+    else {
         // the sysimage was statically linked directly against libjulia-internal
         // use the internal symbols
-        plen = &jl_system_image_size;
-        pointers = &jl_image_pointers;
-        data = &jl_system_image_data;
+        image.size = jl_system_image_size;
+        image.pointers = &jl_image_pointers;
+        image.data = &jl_system_image_data;
     }
 
 #ifdef _OS_WINDOWS_
-    base = (intptr_t)handle;
+    image.base = (intptr_t)handle;
 #else
     Dl_info dlinfo;
-    if (dladdr((void*)pointers, &dlinfo) != 0)
-        base = (intptr_t)dlinfo.dli_fbase;
+    if (dladdr((void*)image.pointers, &dlinfo) != 0)
+        image.base = (intptr_t)dlinfo.dli_fbase;
     else
-        base = 0;
+        image.base = 0;
 #endif
 
-    return (jl_image_buf_t) {
-        .kind = JL_IMAGE_KIND_SO,
-        .handle = handle,
-        .pointers = pointers,
-        .data = data,
-        .size = *plen,
-        .base = base,
-    };
+    return image;
 }
 
 // Allow passing in a module handle directly, rather than a path

From b01a5eaef1357cc572c04452e7af7ff060a5d150 Mon Sep 17 00:00:00 2001
From: Sam Schweigel <sam.schweigel@juliahub.com>
Date: Fri, 5 Sep 2025 17:28:26 -0700
Subject: [PATCH 5/6] Allow linking a system image with jl_image_unpack with
 libjulia

---
 src/null_sysimage.c | 6 ++----
 src/processor.h     | 5 ++---
 src/staticdata.c    | 9 +++------
 3 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/src/null_sysimage.c b/src/null_sysimage.c
index 386842f0c4e77..da50640d11b18 100644
--- a/src/null_sysimage.c
+++ b/src/null_sysimage.c
@@ -7,9 +7,7 @@
  * These symbols support statically linking the sysimage with libjulia-internal.
  *
  * Here we provide dummy definitions that are used when these are not linked
- * together (the default build configuration). The 0 value of jl_system_image_size
+ * together (the default build configuration). The 0 value of jl_image_unpack
  * is used as a sentinel to indicate that the sysimage should be loaded externally.
  **/
-char jl_system_image_data = 0;
-size_t jl_system_image_size = 0;
-jl_image_pointers_t jl_image_pointers = { 0 };
+jl_image_unpack_func_t *jl_image_unpack = NULL;
diff --git a/src/processor.h b/src/processor.h
index 65b634fd0ba26..965e020429598 100644
--- a/src/processor.h
+++ b/src/processor.h
@@ -233,9 +233,8 @@ JL_DLLEXPORT int32_t jl_get_default_nans(void);
  * libjulia-* and the sysimage together (see null_sysimage.c), in which
  * case they allow accessing the local copy of the sysimage.
  **/
-extern char jl_system_image_data;
-extern size_t jl_system_image_size;
-extern jl_image_pointers_t jl_image_pointers;
+typedef void jl_image_unpack_func_t(void *handle, jl_image_buf_t *image);
+extern jl_image_unpack_func_t *jl_image_unpack;
 
 #ifdef __cplusplus
 }
diff --git a/src/staticdata.c b/src/staticdata.c
index 10790422f0539..339e79f91f76e 100644
--- a/src/staticdata.c
+++ b/src/staticdata.c
@@ -3085,7 +3085,6 @@ JL_DLLEXPORT jl_image_buf_t jl_preload_sysimg(const char *fname)
     }
 }
 
-typedef void jl_image_unpack_func_t(void *handle, jl_image_buf_t *image);
 
 static void jl_prefetch_system_image(const char *data, size_t size)
 {
@@ -3173,19 +3172,17 @@ static jl_image_buf_t get_image_buf(void *handle, int is_pkgimage)
     };
 
     // verification passed, lookup the buffer pointers
-    if (jl_system_image_size == 0 || is_pkgimage) {
+    if (jl_image_unpack == NULL || is_pkgimage) {
         // in the usual case, the sysimage was not statically linked to libjulia-internal
         // look up the external sysimage symbols via the dynamic linker
         jl_dlsym(handle, "jl_image_unpack", (void **)&unpack, 1);
-        (*unpack)(handle, &image);
     }
     else {
         // the sysimage was statically linked directly against libjulia-internal
         // use the internal symbols
-        image.size = jl_system_image_size;
-        image.pointers = &jl_image_pointers;
-        image.data = &jl_system_image_data;
+        unpack = &jl_image_unpack;
     }
+    (*unpack)(handle, &image);
 
 #ifdef _OS_WINDOWS_
     image.base = (intptr_t)handle;

From bf49048ab8a4888867d3077cfc7c0dee388f4306 Mon Sep 17 00:00:00 2001
From: Sam Schweigel <sam.schweigel@juliahub.com>
Date: Tue, 7 Oct 2025 11:26:11 -0700
Subject: [PATCH 6/6] Handle errors in jl_image_unpack_zstd better, especially
 on Windows

---
 src/staticdata.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/staticdata.c b/src/staticdata.c
index 339e79f91f76e..ca99f0210a98d 100644
--- a/src/staticdata.c
+++ b/src/staticdata.c
@@ -3120,23 +3120,37 @@ JL_DLLEXPORT void jl_image_unpack_zstd(void *handle, jl_image_buf_t *image)
     image->size = ZSTD_getFrameContentSize(data, *plen);
     size_t page_size = jl_getpagesize(); /* jl_page_size is not set yet when loading sysimg */
     size_t aligned_size = LLT_ALIGN(image->size, page_size);
+    int fail = 0;
 #if defined(_OS_WINDOWS_)
     size_t large_page_size = GetLargePageMinimum();
-    if (image->size > 4 * large_page_size) {
+    image->data = NULL;
+    if (large_page_size > 0 && image->size > 4 * large_page_size) {
         size_t aligned_size = LLT_ALIGN(image->size, large_page_size);
         image->data = (char *)VirtualAlloc(
             NULL, aligned_size, MEM_COMMIT | MEM_RESERVE | MEM_LARGE_PAGES, PAGE_READWRITE);
     }
-    else {
+    if (!image->data) {
+        /* Try small pages if large pages failed. */
         image->data = (char *)VirtualAlloc(NULL, aligned_size, MEM_COMMIT | MEM_RESERVE,
                                            PAGE_READWRITE);
     }
+    fail = !image->data;
+#else
+    image->data = (char *)mmap(NULL, aligned_size, PROT_READ | PROT_WRITE,
+                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    fail = image->data == (void *)-1;
+#endif
+    if (fail) {
+        const char *err;
+#if defined(_OS_WINDOWS_)
+        char err_buf[256];
+        win32_formatmessage(GetLastError(), err_buf, sizeof(err_buf));
+        err = err_buf;
 #else
-    image->data =
-        (char *)mmap(NULL, aligned_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+        err = strerror(errno);
 #endif
-    if (!image->data || image->data == (void *)-1) {
-        jl_printf(JL_STDERR, "ERROR: failed to allocate space for system image\n");
+        jl_printf(JL_STDERR, "ERROR: failed to allocate memory for system image: %s\n",
+                  err);
         jl_exit(1);
     }