asm: refactor to use thumb2 instructions
This commit is contained in:
parent
a78a8ba59b
commit
8f424d49e8
GPG key ID:
EC22E476DC2D3D84
3 changed files with 28 additions and 91 deletions
arch/at91sam3x8e
|
|
@ -1,24 +1,13 @@
|
|||
/* See the end of this file for copyright, license, and warranty information. */
|
||||
|
||||
.syntax unified
|
||||
.thumb
|
||||
.include "asm.S"
|
||||
|
||||
.text
|
||||
|
||||
.extern sched_process_switch
|
||||
|
||||
.thumb_func
|
||||
.global irq_pend_sv
|
||||
.type irq_pend_sv, %function
|
||||
|
||||
/* void irq_pend_sv(void); */
|
||||
irq_pend_sv:
|
||||
/*
|
||||
* There seems to be a limitation in Thumb which prohibits popping to
|
||||
* any register > r7. Hence, we need to split the PUSHes and POPs into
|
||||
* multiple operations and MOV register values around.
|
||||
*/
|
||||
|
||||
func_begin irq_pend_sv
|
||||
/*
|
||||
* Some registers have already been saved by hardware at this point,
|
||||
* we only need to take care of r4-r11 and lr (the latter of which is
|
||||
|
|
@ -26,17 +15,10 @@ irq_pend_sv:
|
|||
* The stuff we push onto the stack manually looks about like this:
|
||||
*
|
||||
* <<< stack grow direction (decreasing addresses) <<<
|
||||
* r8 r9 r10 r11 lr r4 r5 r6 r7
|
||||
* r4 r5 r6 r7 r8 r9 r10 r11 lr
|
||||
*/
|
||||
|
||||
push {r4-r7} /* r4-r7 */
|
||||
|
||||
mov r3, r8
|
||||
mov r4, r9
|
||||
mov r5, r10
|
||||
mov r6, r11
|
||||
mov r7, lr
|
||||
push {r3-r7} /* r8-r11, lr */
|
||||
push {r4-r11,lr}
|
||||
|
||||
/*
|
||||
* Now that our stack is completely saved, we can proceed to call the
|
||||
|
|
@ -54,23 +36,11 @@ irq_pend_sv:
|
|||
* just in reverse order.
|
||||
*/
|
||||
|
||||
pop {r3-r7} /* r8-r11, lr */
|
||||
mov lr, r7
|
||||
mov r11, r6
|
||||
mov r10, r5
|
||||
mov r9, r4
|
||||
mov r8, r3
|
||||
pop {r4-r11,lr}
|
||||
|
||||
pop {r4-r7} /* r4-r7 */
|
||||
|
||||
/*
|
||||
* ... and now get the fuck outta here, hoping I never need to touch
|
||||
* this again, even though deep inside I know I will return here at some
|
||||
* point because something broke (or I feel the need to micro-optimize).
|
||||
*/
|
||||
bx lr
|
||||
|
||||
.size irq_pend_sv, .-irq_pend_sv
|
||||
func_end irq_pend_sv
|
||||
|
||||
/*
|
||||
* This file is part of Ardix.
|
||||
|
|
|
|||
|
|
@ -1,18 +1,13 @@
|
|||
/* See the end of this file for copyright, license, and warranty information. */
|
||||
|
||||
.syntax unified
|
||||
.thumb
|
||||
.include "asm.S"
|
||||
|
||||
.text
|
||||
|
||||
.extern arch_enter
|
||||
|
||||
.thumb_func
|
||||
.global irq_svc
|
||||
.type irq_svc, %function
|
||||
|
||||
/* void irq_svc(void); */
|
||||
irq_svc:
|
||||
func_begin irq_svc
|
||||
/*
|
||||
* Syscalls on Cortex-M use the following parameter calling convention:
|
||||
*
|
||||
|
|
@ -30,30 +25,16 @@ irq_svc:
|
|||
* like in irq_pend_sv, we save everything on the stack to make early
|
||||
* process switching possible in case the syscall is blocking.
|
||||
*/
|
||||
push {r4-r7} /* r4-r7 */
|
||||
|
||||
mov r3, r8
|
||||
mov r4, r9
|
||||
mov r5, r10
|
||||
mov r6, r11
|
||||
mov r7, lr
|
||||
push {r3-r7} /* r8-r11, lr */
|
||||
push {r3-r11,lr} /* r4-r7 */
|
||||
|
||||
mov r0, sp
|
||||
bl arch_enter /* arch_enter(sp); */
|
||||
|
||||
pop {r3-r7} /* r8-r11, lr */
|
||||
mov lr, r7
|
||||
mov r11, r6
|
||||
mov r10, r5
|
||||
mov r9, r4
|
||||
mov r8, r3
|
||||
|
||||
pop {r4-r7} /* r4-r7 */
|
||||
pop {r3-r11,lr}
|
||||
|
||||
bx lr
|
||||
|
||||
.size irq_svc, .-irq_svc
|
||||
func_end irq_svc
|
||||
|
||||
/*
|
||||
* This file is part of Ardix.
|
||||
|
|
|
|||
|
|
@ -1,45 +1,31 @@
|
|||
/* See the end of this file for copyright, license, and warranty information. */
|
||||
|
||||
.syntax unified
|
||||
.thumb
|
||||
.include "asm.S"
|
||||
|
||||
/* this is only invoked from user space, obviously */
|
||||
.section .text.shared
|
||||
|
||||
.thumb_func
|
||||
.global syscall
|
||||
.type syscall, %function
|
||||
/* int syscall(int number, int arg1, int arg2, int arg3, int arg4, int arg5, int arg6); */
|
||||
syscall:
|
||||
push {r4-r5,r7}
|
||||
func_begin syscall
|
||||
|
||||
/*
|
||||
* I HAVE NO IDEA WHY THE F U C K GCC THINKS I CAN'T MOV TWO LOW REGS
|
||||
* IN ONE INSTRUCTION WHEN THAT IS L I T E R A L L Y IN THE ASM OUTPUT
|
||||
* OF GCC WHEN COMPILING SOME C CODE. BUT AT THIS POINT, I WON'T EVEN
|
||||
* BOTHER WITH WHATEVER SHITTY COMPILE OPTION OR PREPROCESSOR DIRECTIVE
|
||||
* I HAVE TO TURN ON IN ORDER FOR THIS PIECE OF SHIT THAT DARES CALLING
|
||||
* ITSELF A COMPILER TO EAT MY SHIT CODE AND SHIT OUT THE SHITTY BINARY
|
||||
* I WANT. FUCK YOU, SYSCALLS WILL JUST TAKE 8 INSTRUCTIONS MORE.
|
||||
* arg | syscall | AAPCS
|
||||
* -------|---------|---------
|
||||
* number | r7 | r0
|
||||
* arg1 | r0 | r1
|
||||
* arg2 | r1 | r2
|
||||
* arg3 | r2 | r3
|
||||
* arg4 | r3 | sp + 0
|
||||
* arg5 | r4 | sp + 4
|
||||
* arg6 | r5 | sp + 8
|
||||
*/
|
||||
|
||||
mov r4, r12
|
||||
push {r4}
|
||||
push {r4-r5,r7}
|
||||
|
||||
mov r12, r0 /* syscall number */
|
||||
mov r7, r12
|
||||
|
||||
mov r12, r1 /* arg1 */
|
||||
mov r0, r12
|
||||
|
||||
mov r12, r2 /* arg2 */
|
||||
mov r1, r12
|
||||
|
||||
mov r12, r3 /* arg3 */
|
||||
mov r2, r12
|
||||
|
||||
pop {r4}
|
||||
mov r12, r4
|
||||
mov r7, r0 /* number */
|
||||
mov r0, r1 /* arg1 */
|
||||
mov r1, r2 /* arg2 */
|
||||
mov r2, r3 /* arg3 */
|
||||
|
||||
/* stack params begin at 12 bytes offset because we already pushed three registers */
|
||||
ldr r3, [sp, #12] /* arg4 */
|
||||
|
|
@ -53,7 +39,7 @@ syscall:
|
|||
/* r0 (return value) is set by the kernel */
|
||||
bx lr
|
||||
|
||||
.size syscall, .-syscall
|
||||
func_end syscall
|
||||
|
||||
/*
|
||||
* This file is part of Ardix.
|
||||
|
|
|
|||
Loading…
Reference in a new issue