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Extract more bits from calc.s; use qemu for testing

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This commit is contained in:
Wesley Moore 2025-02-10 15:51:18 +10:00
parent 8f252c15c6
commit 82a0fde80d
No known key found for this signature in database
6 changed files with 133 additions and 156 deletions

6
Makefile
View file

@ -4,7 +4,7 @@ ASFLAGS=-g -mabi=ilp32e -march=rv32ec
CFLAGS=$(ASFLAGS)
LD=riscv64-unknown-elf-ld
export JQ?=jaq
export RV32EMU?=$(HOME)/Source/github.com/sysprog21/rv32emu/build/rv32emu
export QEMU?=qemu-riscv32
all: calc.elf
@ -14,12 +14,12 @@ check: tests
hello.elf: hello.o
$(LD) -m elf32lriscv $^ -o $@
calc.elf: hex.o calc.o
calc.elf: mem.o hex.o debug.o calc.o
$(LD) -m elf32lriscv -T link.ld $^ -o $@
tests: tests/btohex.elf tests/tohex.elf
tests/btohex.elf: hex.o tests/btohex.o
tests/btohex.elf: mem.o hex.o debug.o tests/btohex.o
$(LD) -m elf32lriscv -T link.ld $^ -o $@
tests/tohex.elf: hex.o tests/tohex.o

150
calc.s
View file

@ -4,59 +4,24 @@
# Provide program starting address to linker
.global _start
.extern tohex
.extern regdump
/* newlib system calls */
.set SYSEXIT, 93
.set SYSWRITE, 64
.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
# x10: ABCDEFGH\n is 14 chars
.section .data
buflen: .byte 0 # length of buf string
# .section .rodata
# .section .bss
.text
_start:
li t1, 0
li t2, 5
# dummy test for jal instruction
.L1:
jal x0, .L2
.L2:
nop
loop:
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 t1, t1, 1
j loop
end:
# do some adding
li a0, 0x80000000 # 0.5
li a1, 1 # 1
li a2, 0x80000000 # 0.5
li a3, 1 # 1
# jal add64
jal add64
#add t1, a0, 0 # copy a0 to t0 as end with overwrite it
jal regdump
@ -82,110 +47,3 @@ add64:
ret
# Print values of all registers (in hex)
# write syscall uses t0, a0, a1, a2
regdump:
# save all registers to preserve their state when entering the function
# except sp, which will be offset by -64
addi sp, sp, -64 # allocate stack space to stash all registers
sw x0, 0(sp)
sw x1, 4(sp)
sw x2, 8(sp)
sw x3, 12(sp)
sw x4, 16(sp)
sw x5, 20(sp)
sw x6, 24(sp)
sw x7, 28(sp)
sw x8, 32(sp)
sw x9, 36(sp)
sw x10, 40(sp)
sw x11, 44(sp)
sw x12, 48(sp)
sw x13, 52(sp)
sw x14, 56(sp)
sw x15, 60(sp)
li t0, SYSWRITE # "write" syscall
li a0, 1 # 1 = standard output (stdout)
la a1, str2 # load address of hello string
li a2, str2_size # length of other string
ecall # invoke syscall to print the string
li s0, 0
li s1, 16
regdump_loop:
beq s0, s1, regdump_done
la a1, regnames # load address of regnames
slli a2, s0, 1 # a2 = s0 * 2
add a1, a1, a2 # a1 = a1 + a2
# copy regname to buf
la a0, buf # load address of buf into a0 as dest
li a2, 2 # copy 2 bytes
addi sp, sp, -4 # allocate stack space
sw ra, 0(sp) # save contents of ra
jal memcpy
lw ra, 0(sp) # restore contents of ra
addi sp, sp, 4 # deallocate stack space
# append ': '
li t0, ':
sb t0, 0(a0)
li t0, 0x20
sb t0, 1(a0)
addi a0, a0, 2 # bump a0 address over ': ' text
mv a1, a0 # load address of output buffer to a1
slli a2, s0, 2 # calculate the offset of the register value relative to sp
add a2, a2, sp # a2 = sp + (s0 * 4)
lw a0, 0(a2) # load register value to format into a0
addi sp, sp, -8 # allocate stack space
sw a1, 4(sp) # save contents of a1
sw ra, 0(sp) # save contents of ra
jal tohex
lw ra, 0(sp) # restore contents of ra
lw a1, 4(sp) # restore contents of a1 (buffer)
addi sp, sp, 8 # deallocate stack space
li t0, '\n # append newline
sb t0, 8(a1)
# print the register name and value
li t0, SYSWRITE # "write" syscall
li a0, 1 # 1 = standard output (stdout)
la a1, buf
li a2, 4+8+1 # length of register name string:
# rr: 12345678\n
ecall # invoke syscall to print the string
addi s0, s0, 1
j regdump_loop
regdump_done:
# TODO: Restore s0 & s1
addi sp, sp, 64 # deallocate stack space
ret
# memcpy, copy n bytes of memory from src to dest
# arguments:
# a0: dest address
# a1: source address
# a2: number of bytes to copy
# temporaries used:
# t0, t1
# return:
# a0: address of dest + n
# a1: address of src + n
#
memcpy:
li t0, 0
memcpy_loop:
# TODO: copy in chunks of 4 bytes if n > 4
beq t0, a2, memcpy_done
lbu t1, 0(a1)
sb t1, 0(a0)
addi a0, a0, 1
addi a1, a1, 1
addi t0, t0, 1
j memcpy_loop
memcpy_done:
ret

93
debug.s Normal file
View file

@ -0,0 +1,93 @@
# Debugging routines
.extern tohex
.extern memcpy
.global regdump
/* newlib system calls */
.set SYSWRITE, 64
.section .rodata
regnames:
.ascii "x0", "ra", "sp", "gp", "tp", "t0", "t1", "t2", "s0", "s1", "a0", "a1", "a2", "a3", "a4", "a5"
.section .bss
buf: .skip 15 # room for 20 byte string
# x10: ABCDEFGH\n is 14 chars
.text
# Print values of all registers (in hex)
# write syscall uses t0, a0, a1, a2
regdump:
# save all registers to preserve their state when entering the function
# except sp, which will be offset by -64
addi sp, sp, -64 # allocate stack space to stash all registers
sw x0, 0(sp)
sw x1, 4(sp)
sw x2, 8(sp)
sw x3, 12(sp)
sw x4, 16(sp)
sw x5, 20(sp)
sw x6, 24(sp)
sw x7, 28(sp)
sw x8, 32(sp)
sw x9, 36(sp)
sw x10, 40(sp)
sw x11, 44(sp)
sw x12, 48(sp)
sw x13, 52(sp)
sw x14, 56(sp)
sw x15, 60(sp)
li s0, 0
li s1, 16
regdump_loop:
beq s0, s1, regdump_done
la a1, regnames # load address of regnames
slli a2, s0, 1 # a2 = s0 * 2
add a1, a1, a2 # a1 = a1 + a2
# copy regname to buf
la a0, buf # load address of buf into a0 as dest
li a2, 2 # copy 2 bytes
addi sp, sp, -4 # allocate stack space
sw ra, 0(sp) # save contents of ra
jal memcpy
lw ra, 0(sp) # restore contents of ra
addi sp, sp, 4 # deallocate stack space
# append ': '
li t0, ':
sb t0, 0(a0)
li t0, 0x20
sb t0, 1(a0)
addi a0, a0, 2 # bump a0 address over ': ' text
mv a1, a0 # load address of output buffer to a1
slli a2, s0, 2 # calculate the offset of the register value relative to sp
add a2, a2, sp # a2 = sp + (s0 * 4)
lw a0, 0(a2) # load register value to format into a0
addi sp, sp, -8 # allocate stack space
sw a1, 4(sp) # save contents of a1
sw ra, 0(sp) # save contents of ra
jal tohex
lw ra, 0(sp) # restore contents of ra
lw a1, 4(sp) # restore contents of a1 (buffer)
addi sp, sp, 8 # deallocate stack space
li t0, '\n # append newline
sb t0, 8(a1)
# print the register name and value
li t0, SYSWRITE # "write" syscall
li a0, 1 # 1 = standard output (stdout)
la a1, buf
li a2, 4+8+1 # length of register name string:
# rr: 12345678\n
ecall # invoke syscall to print the string
addi s0, s0, 1
j regdump_loop
regdump_done:
# TODO: Restore s0 & s1
addi sp, sp, 64 # deallocate stack space
ret

27
mem.s Normal file
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@ -0,0 +1,27 @@
.global memcpy
.text
# memcpy, copy n bytes of memory from src to dest
# arguments:
# a0: dest address
# a1: source address
# a2: number of bytes to copy
# temporaries used:
# t0, t1
# return:
# a0: address of dest + n
# a1: address of src + n
#
memcpy:
li t0, 0
memcpy_loop:
# TODO: copy in chunks of 4 bytes if n > 4
beq t0, a2, memcpy_done
lbu t1, 0(a1)
sb t1, 0(a0)
addi a0, a0, 1
addi a1, a1, 1
addi t0, t0, 1
j memcpy_loop
memcpy_done:
ret

3
tests/btohex.s
View file

@ -5,6 +5,7 @@
.global _start
.extern btohex
.extern regdump
/* newlib system calls */
.set SYSEXIT, 93
@ -13,7 +14,7 @@
_start:
li a0, 0xA5
jal btohex
mv a1, a0
jal regdump
li t0, SYSEXIT # "exit" syscall
la a0, 0 # Use 0 return code

10
tests/test_hex.sh
View file

@ -3,16 +3,14 @@
test_btohex() {
# FIXME: Remove grep when this bug is fixed:
# https://github.com/sysprog21/rv32emu/issues/561
result=$("${RV32EMU}" -d - -q tests/btohex.elf | grep -v '^[0-9]' | "${JQ}" .x11)
result=$("${QEMU}" -B 0x80000000 -s 2k tests/btohex.elf | grep '^a0:')
# 16693 is 5A in ASCII (reversed from input due to little endian)
test $? -eq 0 && test "${result}" -eq 13633
# 3541 is 5A in ASCII (reversed from input due to little endian)
test $? -eq 0 && test "${result}" = "a0: 00003541"
}
test_tohex() {
# FIXME: Remove grep when this bug is fixed:
# https://github.com/sysprog21/rv32emu/issues/561
result=$("${RV32EMU}" -q tests/tohex.elf | grep -v '^[0-9]')
result=$("${QEMU}" -B 0x80000000 -s 2k tests/tohex.elf)
test $? -eq 0 && test "${result}" = "CAFEFEED"
}