From 4193ea8239264c7ee6891e9ef5ee756e13833fb2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Thu, 23 Oct 2025 06:18:22 +0200
Subject: [PATCH] std.start: add sh support

---
 lib/std/start.zig | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/lib/std/start.zig b/lib/std/start.zig
index 7e45bc42ea..4cf2a0956b 100644
--- a/lib/std/start.zig
+++ b/lib/std/start.zig
@@ -212,6 +212,7 @@ fn _start() callconv(.naked) noreturn {
             else
                 ".cfi_undefined ra",
             .s390x => ".cfi_undefined %%r14",
+            .sh, .sheb => ".cfi_undefined pr",
             .sparc, .sparc64 => ".cfi_undefined %%i7",
             .x86 => ".cfi_undefined %%eip",
             .x86_64 => ".cfi_undefined %%rip",
@@ -455,6 +456,21 @@ fn _start() callconv(.naked) noreturn {
             \\ stg  %%r0, 0(%%r15)
             \\ jg %[posixCallMainAndExit]
             ,
+            .sh, .sheb =>
+            // r14 = FP, r15 = SP, pr = LR
+            \\ mov #0, r0
+            \\ lds r0, pr
+            \\ mov r0, r14
+            \\ mov r15, r4
+            \\ mov #-4, r0
+            \\ and r0, r15
+            \\ mov.l 2f, r1
+            \\1:
+            \\ bsrf r1
+            \\2:
+            \\ .balign 4
+            \\ .long %[posixCallMainAndExit]@PCREL - (1b + 4 - .)
+            ,
             .sparc =>
             // argc is stored after a register window (16 registers * 4 bytes).
             // i7 = LR