From f10b226c7703f08b39f21d8739768818c4d57d0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 27 Aug 2024 08:03:35 +0200
Subject: [PATCH 1/4] Compilation: Pass -fPIC for assembly files too, not just
 C files.

There are targets (e.g. MIPS) where PIC actually affects assembler behavior.
---
 src/Compilation.zig | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Compilation.zig b/src/Compilation.zig
index 3d40957a72f84a1244b4fe307415ee20256fc29d..4d4f1527a23e9a11ad6b8ab803ff523e5116ad53 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -5636,10 +5636,6 @@ pub fn addCCArgs(
                 try argv.append("-Werror=date-time");
             }
 
-            if (target_util.supports_fpic(target) and mod.pic) {
-                try argv.append("-fPIC");
-            }
-
             if (mod.unwind_tables) {
                 try argv.append("-funwind-tables");
             } else {
@@ -5730,6 +5726,10 @@ pub fn addCCArgs(
         },
     }
 
+    if (target_util.supports_fpic(target) and mod.pic) {
+        try argv.append("-fPIC");
+    }
+
     try argv.ensureUnusedCapacity(2);
     switch (comp.config.debug_format) {
         .strip => {},
-- 
2.54.0


From 2de7296262b88f3d19ad9cb75f824bf69350c717 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 27 Aug 2024 08:09:47 +0200
Subject: [PATCH 2/4] Compilation: Pass -mthumb for assembly files too, not
 just C files.

---
 src/Compilation.zig | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Compilation.zig b/src/Compilation.zig
index 4d4f1527a23e9a11ad6b8ab803ff523e5116ad53..54fa1208569fcd9abe4bc1c6d9f50fb0a4ffdf58 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -5536,10 +5536,6 @@ pub fn addCCArgs(
                 else => {},
             }
 
-            if (target.cpu.arch.isThumb()) {
-                try argv.append("-mthumb");
-            }
-
             {
                 var san_arg: std.ArrayListUnmanaged(u8) = .{};
                 const prefix = "-fsanitize=";
@@ -5726,6 +5722,10 @@ pub fn addCCArgs(
         },
     }
 
+    if (target.cpu.arch.isThumb()) {
+        try argv.append("-mthumb");
+    }
+
     if (target_util.supports_fpic(target) and mod.pic) {
         try argv.append("-fPIC");
     }
-- 
2.54.0


From f021ad548fd8ad6c7d8d8ea7e7c409c695dce1e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Wed, 28 Aug 2024 10:27:29 +0200
Subject: [PATCH 3/4] musl: Build with -fno-builtin and -mimplicit-it=always
 (for thumb) like upstream.

---
 src/musl.zig | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/musl.zig b/src/musl.zig
index 1c20c209687bc1079f55cc1085fb46777261f1cf..acf59020334909a17a97f116405c2ca18efd8228 100644
--- a/src/musl.zig
+++ b/src/musl.zig
@@ -384,6 +384,7 @@ fn addCcArgs(
     try args.appendSlice(&[_][]const u8{
         "-std=c99",
         "-ffreestanding",
+        "-fno-builtin",
         "-fexcess-precision=standard",
         "-frounding-math",
         "-fno-strict-aliasing",
@@ -422,6 +423,10 @@ fn addCcArgs(
         "-Qunused-arguments",
         "-w", // disable all warnings
     });
+
+    if (target.cpu.arch.isThumb()) {
+        try args.append("-mimplicit-it=always");
+    }
 }
 
 fn start_asm_path(comp: *Compilation, arena: Allocator, basename: []const u8) ![]const u8 {
-- 
2.54.0


From 0ecc6332b4eb1ced547ffa38f57471134aaa4d13 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Thu, 29 Aug 2024 16:07:46 +0200
Subject: [PATCH 4/4] start: Fix arm stack alignment code to work for thumb
 too.

---
 lib/std/start.zig | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/std/start.zig b/lib/std/start.zig
index ea6f347bd6658ff9b99885e12baaa1f2d292664f..5c94a4b591b885109c14f9dbb5406f1169cfd1ad 100644
--- a/lib/std/start.zig
+++ b/lib/std/start.zig
@@ -283,7 +283,9 @@ fn _start() callconv(.Naked) noreturn {
             \\ mov fp, #0
             \\ mov lr, #0
             \\ mov a1, sp
-            \\ and sp, #-16
+            \\ mov ip, sp
+            \\ and ip, ip, #-16
+            \\ mov sp, ip
             \\ b %[posixCallMainAndExit]
             ,
             .csky =>
-- 
2.54.0