From 32b37bb37401b7724e54d2661a2cd174281f30e2 Mon Sep 17 00:00:00 2001
From: Wesley Moore <wes@wezm.net>
Date: Sun, 9 Feb 2025 15:45:37 +1000
Subject: [PATCH] Print register names
---
calc.s | 37 +++++++++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 8 deletions(-)
diff --git a/calc.s b/calc.s
index 2b783d9..58d09cf 100644
--- a/calc.s
+++ b/calc.s
@@ -11,9 +11,12 @@
.section .rodata
str: .ascii "Hello World!\n"
.set str_size, .-str
+
str2: .ascii "regdump\n"
.set str2_size, .-str2
+regnames:
+ .ascii "x0", "ra", "sp", "gp", "tp", "t0", "t1", "t2", "s0", "s1", "a0", "a1", "a2", "a3", "a4", "a5"
.section .bss
buf: .skip 20 # room for 20 byte string
@@ -92,19 +95,37 @@ regdump:
li a2, str2_size # length of other string
ecall # invoke syscall to print the string
- # as a test load something into buf and print it
- la a1, buf # load address of buf into a1
- li a0, 'h
- sb a0, 0(a1)
- li a0, '\n
- sb a0, 1(a1)
- li a2, 2 # length of buf
+ li t1, 0
+ li t2, 16
+regdump_loop:
+ beq t1, t2, regdump_done
+ # a1 = regnames + (2 * t1)
+ # a1 = t1 << 1 + regnames
+ la a1, regnames # load address of regnames
+ slli a2, t1, 1
+ add a1, a1, a2
+
+ # print the register name
li t0, SYSWRITE # "write" syscall
li a0, 1 # 1 = standard output (stdout)
- # li a2, buflen # length of hello string
+ # a1 is the address of the string, calculated above
+ li a2, 2 # length of register name string
ecall # invoke syscall to print the string
+ # add newline
+ la a1, buf # load address of buf into a1
+ li a0, '\n
+ sb a0, 0(a1)
+ li a2, 1 # length of buf
+ li t0, SYSWRITE # "write" syscall
+ li a0, 1 # 1 = standard output (stdout)
+ ecall # invoke syscall to print the string
+
+ addi t1, t1, 1
+ j regdump_loop
+
+regdump_done:
addi sp, sp, 16 # deallocate stack space
ret