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.section .text
.globl preserveregs
preserveregs:
str r4, [r0, #0x10]
str r5, [r0, #0x14]
str r6, [r0, #0x18]
str r7, [r0, #0x1c]
str r8, [r0, #0x20]
str r9, [r0, #0x24]
str r10, [r0, #0x28]
str r11, [r0, #0x2c]
bx lr
.globl restoreregs
restoreregs:
ldr r4, [r0, #0x10]
ldr r5, [r0, #0x14]
ldr r6, [r0, #0x18]
ldr r7, [r0, #0x1c]
ldr r8, [r0, #0x20]
ldr r9, [r0, #0x24]
ldr r10, [r0, #0x28]
ldr r11, [r0, #0x2c]
bx lr
.globl exetask
exetask:
push {r0, r4, r5, r6, r7, r8, r9, r10, r11, lr}
// Restore registers from context switch
ldr r4, [r0, #0x10]
ldr r5, [r0, #0x14]
ldr r6, [r0, #0x18]
ldr r7, [r0, #0x1c]
ldr r8, [r0, #0x20]
ldr r9, [r0, #0x24]
ldr r10, [r0, #0x28]
ldr r11, [r0, #0x2c]
// Preserve system stack
ldr r1, =msp
str sp, [r1]
// Setup task's stack
ldr sp, [r0, #0x34]
// Switch to task
ldr lr, [r0, #0x3c]
blx lr
// Restore system stack
ldr r1, =msp
ldr sp, [r1]
pop {r0, r4, r5, r6, r7, r8, r9, r10, r11, pc}
.section .data
msp:
.space 4
.section .data.stacks
.globl stacks
stacks:
.space 0x100000
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