73f0f7c79b
Patch from Nicolas Pitre ARM processors that have pld instructions are not using those copy_user implementation anymore. Let's remove the useless PLD lines which were half wrong anyway. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
559 lines
13 KiB
ArmAsm
559 lines
13 KiB
ArmAsm
/*
|
|
* linux/arch/arm/lib/uaccess.S
|
|
*
|
|
* Copyright (C) 1995, 1996,1997,1998 Russell King
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Routines to block copy data to/from user memory
|
|
* These are highly optimised both for the 4k page size
|
|
* and for various alignments.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/errno.h>
|
|
|
|
.text
|
|
|
|
#define PAGE_SHIFT 12
|
|
|
|
/* Prototype: int __arch_copy_to_user(void *to, const char *from, size_t n)
|
|
* Purpose : copy a block to user memory from kernel memory
|
|
* Params : to - user memory
|
|
* : from - kernel memory
|
|
* : n - number of bytes to copy
|
|
* Returns : Number of bytes NOT copied.
|
|
*/
|
|
|
|
.c2u_dest_not_aligned:
|
|
rsb ip, ip, #4
|
|
cmp ip, #2
|
|
ldrb r3, [r1], #1
|
|
USER( strbt r3, [r0], #1) @ May fault
|
|
ldrgeb r3, [r1], #1
|
|
USER( strgebt r3, [r0], #1) @ May fault
|
|
ldrgtb r3, [r1], #1
|
|
USER( strgtbt r3, [r0], #1) @ May fault
|
|
sub r2, r2, ip
|
|
b .c2u_dest_aligned
|
|
|
|
ENTRY(__arch_copy_to_user)
|
|
stmfd sp!, {r2, r4 - r7, lr}
|
|
cmp r2, #4
|
|
blt .c2u_not_enough
|
|
ands ip, r0, #3
|
|
bne .c2u_dest_not_aligned
|
|
.c2u_dest_aligned:
|
|
|
|
ands ip, r1, #3
|
|
bne .c2u_src_not_aligned
|
|
/*
|
|
* Seeing as there has to be at least 8 bytes to copy, we can
|
|
* copy one word, and force a user-mode page fault...
|
|
*/
|
|
|
|
.c2u_0fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .c2u_0nowords
|
|
ldr r3, [r1], #4
|
|
USER( strt r3, [r0], #4) @ May fault
|
|
mov ip, r0, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .c2u_0fupi
|
|
/*
|
|
* ip = max no. of bytes to copy before needing another "strt" insn
|
|
*/
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #32
|
|
blt .c2u_0rem8lp
|
|
|
|
.c2u_0cpy8lp: ldmia r1!, {r3 - r6}
|
|
stmia r0!, {r3 - r6} @ Shouldnt fault
|
|
ldmia r1!, {r3 - r6}
|
|
subs ip, ip, #32
|
|
stmia r0!, {r3 - r6} @ Shouldnt fault
|
|
bpl .c2u_0cpy8lp
|
|
|
|
.c2u_0rem8lp: cmn ip, #16
|
|
ldmgeia r1!, {r3 - r6}
|
|
stmgeia r0!, {r3 - r6} @ Shouldnt fault
|
|
tst ip, #8
|
|
ldmneia r1!, {r3 - r4}
|
|
stmneia r0!, {r3 - r4} @ Shouldnt fault
|
|
tst ip, #4
|
|
ldrne r3, [r1], #4
|
|
strnet r3, [r0], #4 @ Shouldnt fault
|
|
ands ip, ip, #3
|
|
beq .c2u_0fupi
|
|
.c2u_0nowords: teq ip, #0
|
|
beq .c2u_finished
|
|
.c2u_nowords: cmp ip, #2
|
|
ldrb r3, [r1], #1
|
|
USER( strbt r3, [r0], #1) @ May fault
|
|
ldrgeb r3, [r1], #1
|
|
USER( strgebt r3, [r0], #1) @ May fault
|
|
ldrgtb r3, [r1], #1
|
|
USER( strgtbt r3, [r0], #1) @ May fault
|
|
b .c2u_finished
|
|
|
|
.c2u_not_enough:
|
|
movs ip, r2
|
|
bne .c2u_nowords
|
|
.c2u_finished: mov r0, #0
|
|
LOADREGS(fd,sp!,{r2, r4 - r7, pc})
|
|
|
|
.c2u_src_not_aligned:
|
|
bic r1, r1, #3
|
|
ldr r7, [r1], #4
|
|
cmp ip, #2
|
|
bgt .c2u_3fupi
|
|
beq .c2u_2fupi
|
|
.c2u_1fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .c2u_1nowords
|
|
mov r3, r7, pull #8
|
|
ldr r7, [r1], #4
|
|
orr r3, r3, r7, push #24
|
|
USER( strt r3, [r0], #4) @ May fault
|
|
mov ip, r0, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .c2u_1fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .c2u_1rem8lp
|
|
|
|
.c2u_1cpy8lp: mov r3, r7, pull #8
|
|
ldmia r1!, {r4 - r7}
|
|
subs ip, ip, #16
|
|
orr r3, r3, r4, push #24
|
|
mov r4, r4, pull #8
|
|
orr r4, r4, r5, push #24
|
|
mov r5, r5, pull #8
|
|
orr r5, r5, r6, push #24
|
|
mov r6, r6, pull #8
|
|
orr r6, r6, r7, push #24
|
|
stmia r0!, {r3 - r6} @ Shouldnt fault
|
|
bpl .c2u_1cpy8lp
|
|
|
|
.c2u_1rem8lp: tst ip, #8
|
|
movne r3, r7, pull #8
|
|
ldmneia r1!, {r4, r7}
|
|
orrne r3, r3, r4, push #24
|
|
movne r4, r4, pull #8
|
|
orrne r4, r4, r7, push #24
|
|
stmneia r0!, {r3 - r4} @ Shouldnt fault
|
|
tst ip, #4
|
|
movne r3, r7, pull #8
|
|
ldrne r7, [r1], #4
|
|
orrne r3, r3, r7, push #24
|
|
strnet r3, [r0], #4 @ Shouldnt fault
|
|
ands ip, ip, #3
|
|
beq .c2u_1fupi
|
|
.c2u_1nowords: mov r3, r7, get_byte_1
|
|
teq ip, #0
|
|
beq .c2u_finished
|
|
cmp ip, #2
|
|
USER( strbt r3, [r0], #1) @ May fault
|
|
movge r3, r7, get_byte_2
|
|
USER( strgebt r3, [r0], #1) @ May fault
|
|
movgt r3, r7, get_byte_3
|
|
USER( strgtbt r3, [r0], #1) @ May fault
|
|
b .c2u_finished
|
|
|
|
.c2u_2fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .c2u_2nowords
|
|
mov r3, r7, pull #16
|
|
ldr r7, [r1], #4
|
|
orr r3, r3, r7, push #16
|
|
USER( strt r3, [r0], #4) @ May fault
|
|
mov ip, r0, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .c2u_2fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .c2u_2rem8lp
|
|
|
|
.c2u_2cpy8lp: mov r3, r7, pull #16
|
|
ldmia r1!, {r4 - r7}
|
|
subs ip, ip, #16
|
|
orr r3, r3, r4, push #16
|
|
mov r4, r4, pull #16
|
|
orr r4, r4, r5, push #16
|
|
mov r5, r5, pull #16
|
|
orr r5, r5, r6, push #16
|
|
mov r6, r6, pull #16
|
|
orr r6, r6, r7, push #16
|
|
stmia r0!, {r3 - r6} @ Shouldnt fault
|
|
bpl .c2u_2cpy8lp
|
|
|
|
.c2u_2rem8lp: tst ip, #8
|
|
movne r3, r7, pull #16
|
|
ldmneia r1!, {r4, r7}
|
|
orrne r3, r3, r4, push #16
|
|
movne r4, r4, pull #16
|
|
orrne r4, r4, r7, push #16
|
|
stmneia r0!, {r3 - r4} @ Shouldnt fault
|
|
tst ip, #4
|
|
movne r3, r7, pull #16
|
|
ldrne r7, [r1], #4
|
|
orrne r3, r3, r7, push #16
|
|
strnet r3, [r0], #4 @ Shouldnt fault
|
|
ands ip, ip, #3
|
|
beq .c2u_2fupi
|
|
.c2u_2nowords: mov r3, r7, get_byte_2
|
|
teq ip, #0
|
|
beq .c2u_finished
|
|
cmp ip, #2
|
|
USER( strbt r3, [r0], #1) @ May fault
|
|
movge r3, r7, get_byte_3
|
|
USER( strgebt r3, [r0], #1) @ May fault
|
|
ldrgtb r3, [r1], #0
|
|
USER( strgtbt r3, [r0], #1) @ May fault
|
|
b .c2u_finished
|
|
|
|
.c2u_3fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .c2u_3nowords
|
|
mov r3, r7, pull #24
|
|
ldr r7, [r1], #4
|
|
orr r3, r3, r7, push #8
|
|
USER( strt r3, [r0], #4) @ May fault
|
|
mov ip, r0, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .c2u_3fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .c2u_3rem8lp
|
|
|
|
.c2u_3cpy8lp: mov r3, r7, pull #24
|
|
ldmia r1!, {r4 - r7}
|
|
subs ip, ip, #16
|
|
orr r3, r3, r4, push #8
|
|
mov r4, r4, pull #24
|
|
orr r4, r4, r5, push #8
|
|
mov r5, r5, pull #24
|
|
orr r5, r5, r6, push #8
|
|
mov r6, r6, pull #24
|
|
orr r6, r6, r7, push #8
|
|
stmia r0!, {r3 - r6} @ Shouldnt fault
|
|
bpl .c2u_3cpy8lp
|
|
|
|
.c2u_3rem8lp: tst ip, #8
|
|
movne r3, r7, pull #24
|
|
ldmneia r1!, {r4, r7}
|
|
orrne r3, r3, r4, push #8
|
|
movne r4, r4, pull #24
|
|
orrne r4, r4, r7, push #8
|
|
stmneia r0!, {r3 - r4} @ Shouldnt fault
|
|
tst ip, #4
|
|
movne r3, r7, pull #24
|
|
ldrne r7, [r1], #4
|
|
orrne r3, r3, r7, push #8
|
|
strnet r3, [r0], #4 @ Shouldnt fault
|
|
ands ip, ip, #3
|
|
beq .c2u_3fupi
|
|
.c2u_3nowords: mov r3, r7, get_byte_3
|
|
teq ip, #0
|
|
beq .c2u_finished
|
|
cmp ip, #2
|
|
USER( strbt r3, [r0], #1) @ May fault
|
|
ldrgeb r3, [r1], #1
|
|
USER( strgebt r3, [r0], #1) @ May fault
|
|
ldrgtb r3, [r1], #0
|
|
USER( strgtbt r3, [r0], #1) @ May fault
|
|
b .c2u_finished
|
|
|
|
.section .fixup,"ax"
|
|
.align 0
|
|
9001: LOADREGS(fd,sp!, {r0, r4 - r7, pc})
|
|
.previous
|
|
|
|
/* Prototype: unsigned long __arch_copy_from_user(void *to,const void *from,unsigned long n);
|
|
* Purpose : copy a block from user memory to kernel memory
|
|
* Params : to - kernel memory
|
|
* : from - user memory
|
|
* : n - number of bytes to copy
|
|
* Returns : Number of bytes NOT copied.
|
|
*/
|
|
.cfu_dest_not_aligned:
|
|
rsb ip, ip, #4
|
|
cmp ip, #2
|
|
USER( ldrbt r3, [r1], #1) @ May fault
|
|
strb r3, [r0], #1
|
|
USER( ldrgebt r3, [r1], #1) @ May fault
|
|
strgeb r3, [r0], #1
|
|
USER( ldrgtbt r3, [r1], #1) @ May fault
|
|
strgtb r3, [r0], #1
|
|
sub r2, r2, ip
|
|
b .cfu_dest_aligned
|
|
|
|
ENTRY(__arch_copy_from_user)
|
|
stmfd sp!, {r0, r2, r4 - r7, lr}
|
|
cmp r2, #4
|
|
blt .cfu_not_enough
|
|
ands ip, r0, #3
|
|
bne .cfu_dest_not_aligned
|
|
.cfu_dest_aligned:
|
|
ands ip, r1, #3
|
|
bne .cfu_src_not_aligned
|
|
/*
|
|
* Seeing as there has to be at least 8 bytes to copy, we can
|
|
* copy one word, and force a user-mode page fault...
|
|
*/
|
|
|
|
.cfu_0fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .cfu_0nowords
|
|
USER( ldrt r3, [r1], #4)
|
|
str r3, [r0], #4
|
|
mov ip, r1, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .cfu_0fupi
|
|
/*
|
|
* ip = max no. of bytes to copy before needing another "strt" insn
|
|
*/
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #32
|
|
blt .cfu_0rem8lp
|
|
|
|
.cfu_0cpy8lp: ldmia r1!, {r3 - r6} @ Shouldnt fault
|
|
stmia r0!, {r3 - r6}
|
|
ldmia r1!, {r3 - r6} @ Shouldnt fault
|
|
subs ip, ip, #32
|
|
stmia r0!, {r3 - r6}
|
|
bpl .cfu_0cpy8lp
|
|
|
|
.cfu_0rem8lp: cmn ip, #16
|
|
ldmgeia r1!, {r3 - r6} @ Shouldnt fault
|
|
stmgeia r0!, {r3 - r6}
|
|
tst ip, #8
|
|
ldmneia r1!, {r3 - r4} @ Shouldnt fault
|
|
stmneia r0!, {r3 - r4}
|
|
tst ip, #4
|
|
ldrnet r3, [r1], #4 @ Shouldnt fault
|
|
strne r3, [r0], #4
|
|
ands ip, ip, #3
|
|
beq .cfu_0fupi
|
|
.cfu_0nowords: teq ip, #0
|
|
beq .cfu_finished
|
|
.cfu_nowords: cmp ip, #2
|
|
USER( ldrbt r3, [r1], #1) @ May fault
|
|
strb r3, [r0], #1
|
|
USER( ldrgebt r3, [r1], #1) @ May fault
|
|
strgeb r3, [r0], #1
|
|
USER( ldrgtbt r3, [r1], #1) @ May fault
|
|
strgtb r3, [r0], #1
|
|
b .cfu_finished
|
|
|
|
.cfu_not_enough:
|
|
movs ip, r2
|
|
bne .cfu_nowords
|
|
.cfu_finished: mov r0, #0
|
|
add sp, sp, #8
|
|
LOADREGS(fd,sp!,{r4 - r7, pc})
|
|
|
|
.cfu_src_not_aligned:
|
|
bic r1, r1, #3
|
|
USER( ldrt r7, [r1], #4) @ May fault
|
|
cmp ip, #2
|
|
bgt .cfu_3fupi
|
|
beq .cfu_2fupi
|
|
.cfu_1fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .cfu_1nowords
|
|
mov r3, r7, pull #8
|
|
USER( ldrt r7, [r1], #4) @ May fault
|
|
orr r3, r3, r7, push #24
|
|
str r3, [r0], #4
|
|
mov ip, r1, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .cfu_1fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .cfu_1rem8lp
|
|
|
|
.cfu_1cpy8lp: mov r3, r7, pull #8
|
|
ldmia r1!, {r4 - r7} @ Shouldnt fault
|
|
subs ip, ip, #16
|
|
orr r3, r3, r4, push #24
|
|
mov r4, r4, pull #8
|
|
orr r4, r4, r5, push #24
|
|
mov r5, r5, pull #8
|
|
orr r5, r5, r6, push #24
|
|
mov r6, r6, pull #8
|
|
orr r6, r6, r7, push #24
|
|
stmia r0!, {r3 - r6}
|
|
bpl .cfu_1cpy8lp
|
|
|
|
.cfu_1rem8lp: tst ip, #8
|
|
movne r3, r7, pull #8
|
|
ldmneia r1!, {r4, r7} @ Shouldnt fault
|
|
orrne r3, r3, r4, push #24
|
|
movne r4, r4, pull #8
|
|
orrne r4, r4, r7, push #24
|
|
stmneia r0!, {r3 - r4}
|
|
tst ip, #4
|
|
movne r3, r7, pull #8
|
|
USER( ldrnet r7, [r1], #4) @ May fault
|
|
orrne r3, r3, r7, push #24
|
|
strne r3, [r0], #4
|
|
ands ip, ip, #3
|
|
beq .cfu_1fupi
|
|
.cfu_1nowords: mov r3, r7, get_byte_1
|
|
teq ip, #0
|
|
beq .cfu_finished
|
|
cmp ip, #2
|
|
strb r3, [r0], #1
|
|
movge r3, r7, get_byte_2
|
|
strgeb r3, [r0], #1
|
|
movgt r3, r7, get_byte_3
|
|
strgtb r3, [r0], #1
|
|
b .cfu_finished
|
|
|
|
.cfu_2fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .cfu_2nowords
|
|
mov r3, r7, pull #16
|
|
USER( ldrt r7, [r1], #4) @ May fault
|
|
orr r3, r3, r7, push #16
|
|
str r3, [r0], #4
|
|
mov ip, r1, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .cfu_2fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .cfu_2rem8lp
|
|
|
|
.cfu_2cpy8lp: mov r3, r7, pull #16
|
|
ldmia r1!, {r4 - r7} @ Shouldnt fault
|
|
subs ip, ip, #16
|
|
orr r3, r3, r4, push #16
|
|
mov r4, r4, pull #16
|
|
orr r4, r4, r5, push #16
|
|
mov r5, r5, pull #16
|
|
orr r5, r5, r6, push #16
|
|
mov r6, r6, pull #16
|
|
orr r6, r6, r7, push #16
|
|
stmia r0!, {r3 - r6}
|
|
bpl .cfu_2cpy8lp
|
|
|
|
.cfu_2rem8lp: tst ip, #8
|
|
movne r3, r7, pull #16
|
|
ldmneia r1!, {r4, r7} @ Shouldnt fault
|
|
orrne r3, r3, r4, push #16
|
|
movne r4, r4, pull #16
|
|
orrne r4, r4, r7, push #16
|
|
stmneia r0!, {r3 - r4}
|
|
tst ip, #4
|
|
movne r3, r7, pull #16
|
|
USER( ldrnet r7, [r1], #4) @ May fault
|
|
orrne r3, r3, r7, push #16
|
|
strne r3, [r0], #4
|
|
ands ip, ip, #3
|
|
beq .cfu_2fupi
|
|
.cfu_2nowords: mov r3, r7, get_byte_2
|
|
teq ip, #0
|
|
beq .cfu_finished
|
|
cmp ip, #2
|
|
strb r3, [r0], #1
|
|
movge r3, r7, get_byte_3
|
|
strgeb r3, [r0], #1
|
|
USER( ldrgtbt r3, [r1], #0) @ May fault
|
|
strgtb r3, [r0], #1
|
|
b .cfu_finished
|
|
|
|
.cfu_3fupi: subs r2, r2, #4
|
|
addmi ip, r2, #4
|
|
bmi .cfu_3nowords
|
|
mov r3, r7, pull #24
|
|
USER( ldrt r7, [r1], #4) @ May fault
|
|
orr r3, r3, r7, push #8
|
|
str r3, [r0], #4
|
|
mov ip, r1, lsl #32 - PAGE_SHIFT
|
|
rsb ip, ip, #0
|
|
movs ip, ip, lsr #32 - PAGE_SHIFT
|
|
beq .cfu_3fupi
|
|
cmp r2, ip
|
|
movlt ip, r2
|
|
sub r2, r2, ip
|
|
subs ip, ip, #16
|
|
blt .cfu_3rem8lp
|
|
|
|
.cfu_3cpy8lp: mov r3, r7, pull #24
|
|
ldmia r1!, {r4 - r7} @ Shouldnt fault
|
|
orr r3, r3, r4, push #8
|
|
mov r4, r4, pull #24
|
|
orr r4, r4, r5, push #8
|
|
mov r5, r5, pull #24
|
|
orr r5, r5, r6, push #8
|
|
mov r6, r6, pull #24
|
|
orr r6, r6, r7, push #8
|
|
stmia r0!, {r3 - r6}
|
|
subs ip, ip, #16
|
|
bpl .cfu_3cpy8lp
|
|
|
|
.cfu_3rem8lp: tst ip, #8
|
|
movne r3, r7, pull #24
|
|
ldmneia r1!, {r4, r7} @ Shouldnt fault
|
|
orrne r3, r3, r4, push #8
|
|
movne r4, r4, pull #24
|
|
orrne r4, r4, r7, push #8
|
|
stmneia r0!, {r3 - r4}
|
|
tst ip, #4
|
|
movne r3, r7, pull #24
|
|
USER( ldrnet r7, [r1], #4) @ May fault
|
|
orrne r3, r3, r7, push #8
|
|
strne r3, [r0], #4
|
|
ands ip, ip, #3
|
|
beq .cfu_3fupi
|
|
.cfu_3nowords: mov r3, r7, get_byte_3
|
|
teq ip, #0
|
|
beq .cfu_finished
|
|
cmp ip, #2
|
|
strb r3, [r0], #1
|
|
USER( ldrgebt r3, [r1], #1) @ May fault
|
|
strgeb r3, [r0], #1
|
|
USER( ldrgtbt r3, [r1], #1) @ May fault
|
|
strgtb r3, [r0], #1
|
|
b .cfu_finished
|
|
|
|
.section .fixup,"ax"
|
|
.align 0
|
|
/*
|
|
* We took an exception. r0 contains a pointer to
|
|
* the byte not copied.
|
|
*/
|
|
9001: ldr r2, [sp], #4 @ void *to
|
|
sub r2, r0, r2 @ bytes copied
|
|
ldr r1, [sp], #4 @ unsigned long count
|
|
subs r4, r1, r2 @ bytes left to copy
|
|
movne r1, r4
|
|
blne __memzero
|
|
mov r0, r4
|
|
LOADREGS(fd,sp!, {r4 - r7, pc})
|
|
.previous
|
|
|