From 6fa59d204fbdf780c02bce41edc1144f436e49e1 Mon Sep 17 00:00:00 2001
From: wborgeaud <williamborgeaud@gmail.com>
Date: Mon, 3 Apr 2023 16:39:18 +0200
Subject: [PATCH] Fix MSTORE8 (#955)

* Fix MSTORE8

* Small optimization
---
 evm/src/cpu/kernel/asm/memory/syscalls.asm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/evm/src/cpu/kernel/asm/memory/syscalls.asm b/evm/src/cpu/kernel/asm/memory/syscalls.asm
index 082b44fa..3a233856 100644
--- a/evm/src/cpu/kernel/asm/memory/syscalls.asm
+++ b/evm/src/cpu/kernel/asm/memory/syscalls.asm
@@ -100,7 +100,8 @@ global sys_mstore8:
     // stack: expanded_num_bytes, kexit_info, offset, value
     %update_mem_bytes
     // stack: kexit_info, offset, value
-    %stack (kexit_info, offset, value) -> (offset, value, kexit_info)
+    %stack (kexit_info, offset, value) -> (value, 0x100, offset, kexit_info)
+    MOD SWAP1
     %mstore_current(@SEGMENT_MAIN_MEMORY)
     // stack: kexit_info
     EXIT_KERNEL