From ba9abb1cc09c37ae86e3b1aaa8bec81353b2baf7 Mon Sep 17 00:00:00 2001
From: Wesley Moore <wes@wezm.net>
Date: Sun, 9 Feb 2025 11:32:46 +1000
Subject: [PATCH] Fix hello.s so that it only prints 5 times and exits
---
README.md | 2 ++
hello.s | 8 ++++----
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/README.md b/README.md
index 2269796..f604ebf 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,8 @@ Resources
### Syscalls on RV32E
+[Syscalls supported by rv32emu](https://github.com/sysprog21/rv32emu/blob/master/docs/syscall.md).
+
Consensus seems to be pass the syscall number in `t0`:
* https://github.com/riscvarchive/riscv-qemu/pull/61
diff --git a/hello.s b/hello.s
index 207b616..531c32f 100644
--- a/hello.s
+++ b/hello.s
@@ -14,8 +14,8 @@ str: .ascii "Hello World!\n"
.text
_start:
- li t0, 0
- li t1, 5
+ li t1, 0
+ li t2, 5
# dummy test for jal instruction
.L1:
@@ -24,14 +24,14 @@ _start:
nop
loop:
- beq t0, t1, end
+ beq t1, t2, end
li t0, SYSWRITE # "write" syscall
li a0, 1 # 1 = standard output (stdout)
la a1, str # load address of hello string
li a2, str_size # length of hello string
ecall # invoke syscall to print the string
- addi t0, t0, 1
+ addi t1, t1, 1
j loop
end: