From 6fac71ec74a54792334381b739310685f4b38ba3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Sun, 21 Jul 2024 16:56:52 +0200
Subject: [PATCH] std.os.linux.start_pie: Add m68k support.

---
 lib/std/os/linux/start_pie.zig | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/std/os/linux/start_pie.zig b/lib/std/os/linux/start_pie.zig
index b16a4e6004..0d752e43c7 100644
--- a/lib/std/os/linux/start_pie.zig
+++ b/lib/std/os/linux/start_pie.zig
@@ -8,6 +8,7 @@ const R_386_RELATIVE = 8;
 const R_ARM_RELATIVE = 23;
 const R_AARCH64_RELATIVE = 1027;
 const R_LARCH_RELATIVE = 3;
+const R_68K_RELATIVE = 22;
 const R_RISCV_RELATIVE = 3;
 const R_SPARC_RELATIVE = 22;
 
@@ -17,6 +18,7 @@ const R_RELATIVE = switch (builtin.cpu.arch) {
     .arm => R_ARM_RELATIVE,
     .aarch64 => R_AARCH64_RELATIVE,
     .loongarch32, .loongarch64 => R_LARCH_RELATIVE,
+    .m68k => R_68K_RELATIVE,
     .riscv64 => R_RISCV_RELATIVE,
     else => @compileError("Missing R_RELATIVE definition for this target"),
 };
@@ -65,6 +67,15 @@ fn getDynamicSymbol() [*]elf.Dyn {
             \\ la.local %[ret], _DYNAMIC
             : [ret] "=r" (-> [*]elf.Dyn),
         ),
+        // Note that the - 8 is needed because pc in the second lea instruction points into the
+        // middle of that instruction. (The first lea is 6 bytes, the second is 4 bytes.)
+        .m68k => asm volatile (
+            \\ .weak _DYNAMIC
+            \\ .hidden _DYNAMIC
+            \\ lea _DYNAMIC - . - 8, %[ret]
+            \\ lea (%[ret], %%pc), %[ret]
+            : [ret] "=r" (-> [*]elf.Dyn),
+        ),
         .riscv64 => asm volatile (
             \\ .weak _DYNAMIC
             \\ .hidden _DYNAMIC