From 982510f8d565895cd6b467da092d2feb851aabe7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 30 Jul 2024 04:02:49 +0200
Subject: [PATCH] start: Initialize gp to __global_pointer$ on riscv.

---
 lib/std/start.zig | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/std/start.zig b/lib/std/start.zig
index bca0922fb3..7b68f99b9f 100644
--- a/lib/std/start.zig
+++ b/lib/std/start.zig
@@ -273,6 +273,14 @@ fn _start() callconv(.Naked) noreturn {
             \\ b %[posixCallMainAndExit]
             ,
             .riscv32, .riscv64 =>
+            // The RISC-V ELF ABI assumes that `gp` is set to the value of `__global_pointer$` at
+            // startup in order for GP relaxation to work, even in static builds.
+            \\ .weak __global_pointer$
+            \\ .hidden __global_pointer$
+            \\ .option push
+            \\ .option norelax
+            \\ lla gp, __global_pointer$
+            \\ .option pop
             \\ li s0, 0
             \\ li ra, 0
             \\ mv a0, sp