mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-24 12:09:58 +00:00
ccbaa553a1
Add runtime supporting the nios2-semi.c interface. Execute the hello and memory multiarch tests. Cc: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-64-richard.henderson@linaro.org>
219 lines
3.4 KiB
ArmAsm
219 lines
3.4 KiB
ArmAsm
/*
|
|
* Minimal Nios2 system boot code.
|
|
*
|
|
* Copyright Linaro Ltd 2022
|
|
* SPDX-License-Identifier: GPL-2.0-or-later
|
|
*/
|
|
|
|
#include "semicall.h"
|
|
|
|
.text
|
|
.set noat
|
|
|
|
_start:
|
|
/* Linker script defines stack at end of ram. */
|
|
movia sp, __stack
|
|
|
|
/* Install trampoline to _fast_tlb_miss at hardcoded vector. */
|
|
movia r4, 0xc0000100
|
|
movia r5, _ftm_tramp
|
|
movi r6, .L__ftm_end - _ftm_tramp
|
|
call memcpy
|
|
|
|
/* Zero the bss to satisfy C. */
|
|
movia r4, __bss_start
|
|
movia r6, __bss_end
|
|
sub r6, r6, r4
|
|
movi r5, 0
|
|
call memset
|
|
|
|
/* Test! */
|
|
call main
|
|
|
|
/* Exit with main's return value. */
|
|
movi r4, HOSTED_EXIT
|
|
mov r5, r2
|
|
semihosting_call
|
|
|
|
.globl _start
|
|
.type _start, @function
|
|
.size _start, . - _start
|
|
|
|
_ftm_tramp:
|
|
movia et, _fast_tlb_miss
|
|
jmp et
|
|
.L__ftm_end:
|
|
|
|
.type _ftm_tramp, @function
|
|
.size _ftm_tramp, . - _ftm_tramp
|
|
|
|
#define dst r4
|
|
#define src r5
|
|
#define len r6
|
|
|
|
memcpy:
|
|
/* Store return value right away, per API */
|
|
mov r2, dst
|
|
|
|
/* Check for both dst and src aligned. */
|
|
or at, dst, src
|
|
andi at, at, 3
|
|
bne at, zero, .L_mc_test1
|
|
|
|
/* Copy blocks of 8. */
|
|
|
|
movi at, 8
|
|
bltu len, at, .L_mc_test4
|
|
|
|
.L_mc_loop8:
|
|
ldw r8, 0(src)
|
|
ldw r9, 4(src)
|
|
addi src, src, 8
|
|
addi dst, dst, 8
|
|
subi len, len, 8
|
|
stw r8, -8(dst)
|
|
stw r9, -4(dst)
|
|
bgeu len, at, .L_mc_loop8
|
|
|
|
/* Copy final aligned block of 4. */
|
|
|
|
.L_mc_test4:
|
|
movi at, 4
|
|
bltu len, at, .L_mc_test1
|
|
|
|
ldw r8, 0(src)
|
|
addi src, src, 4
|
|
addi dst, dst, 4
|
|
subi len, len, 4
|
|
stw r8, -4(dst)
|
|
|
|
/* Copy single bytes to finish. */
|
|
|
|
.L_mc_test1:
|
|
beq len, zero, .L_mc_done
|
|
|
|
.L_mc_loop1:
|
|
ldb r8, 0(src)
|
|
addi src, src, 1
|
|
addi dst, dst, 1
|
|
subi len, len, 1
|
|
stb r8, -1(dst)
|
|
bne len, zero, .L_mc_loop1
|
|
|
|
.L_mc_done:
|
|
ret
|
|
|
|
#undef dst
|
|
#undef src
|
|
#undef len
|
|
|
|
.global memcpy
|
|
.type memcpy, @function
|
|
.size memcpy, . - memcpy
|
|
|
|
#define dst r4
|
|
#define val r5
|
|
#define len r6
|
|
|
|
memset:
|
|
/* Store return value right away, per API */
|
|
mov r2, dst
|
|
|
|
/* Check for small blocks; fall back to bytewise. */
|
|
movi r3, 8
|
|
bltu len, r3, .L_ms_test1
|
|
|
|
/* Replicate the byte across the word. */
|
|
andi val, val, 0xff
|
|
slli at, val, 8
|
|
or val, val, at
|
|
slli at, val, 16
|
|
or val, val, at
|
|
|
|
/* Check for destination alignment; realign if needed. */
|
|
andi at, dst, 3
|
|
bne at, zero, .L_ms_align
|
|
|
|
/* Set blocks of 8. */
|
|
|
|
.L_ms_loop8:
|
|
stw val, 0(dst)
|
|
stw val, 4(dst)
|
|
addi dst, dst, 8
|
|
subi len, len, 8
|
|
bgeu len, r3, .L_ms_loop8
|
|
|
|
/* Set final aligned block of 4. */
|
|
|
|
.L_ms_test4:
|
|
movi at, 4
|
|
bltu len, at, .L_ms_test1
|
|
|
|
stw r8, 0(dst)
|
|
addi dst, dst, 4
|
|
subi len, len, 4
|
|
stw r8, -4(dst)
|
|
|
|
/* Set single bytes to finish. */
|
|
|
|
.L_ms_test1:
|
|
beq len, zero, .L_ms_done
|
|
|
|
.L_ms_loop1:
|
|
stb r8, 0(dst)
|
|
addi dst, dst, 1
|
|
subi len, len, 1
|
|
bne len, zero, .L_ms_loop1
|
|
|
|
.L_ms_done:
|
|
ret
|
|
|
|
/* Realign for a large block, len >= 8. */
|
|
.L_ms_align:
|
|
andi at, dst, 1
|
|
beq at, zero, 2f
|
|
|
|
stb val, 0(dst)
|
|
addi dst, dst, 1
|
|
subi len, len, 1
|
|
|
|
2: andi at, dst, 2
|
|
beq at, zero, 4f
|
|
|
|
sth val, 0(dst)
|
|
addi dst, dst, 2
|
|
subi len, len, 2
|
|
|
|
4: bgeu len, r3, .L_ms_loop8
|
|
br .L_ms_test4
|
|
|
|
#undef dst
|
|
#undef val
|
|
#undef len
|
|
|
|
.global memset
|
|
.type memset, @function
|
|
.size memset, . - memset
|
|
|
|
/*
|
|
* void __sys_outc(char c);
|
|
*/
|
|
__sys_outc:
|
|
subi sp, sp, 16
|
|
stb r4, 0(sp) /* buffer[0] = c */
|
|
movi at, 1
|
|
stw at, 4(sp) /* STDOUT_FILENO */
|
|
stw sp, 8(sp) /* buffer */
|
|
stw at, 12(sp) /* len */
|
|
|
|
movi r4, HOSTED_WRITE
|
|
addi r5, sp, 4
|
|
semihosting_call
|
|
|
|
addi sp, sp, 16
|
|
ret
|
|
|
|
.global __sys_outc
|
|
.type __sys_outc, @function
|
|
.size __sys_outc, . - __sys_outc
|