Files
linux-kernel-module-cheat/baremetal/arch/aarch64/no_bootloader/multicore.S
Ciro Santilli 六四事件 法轮功 de05e91689 baremetal: arm multicore attempt
2018-11-22 00:00:01 +00:00

36 lines
672 B
ArmAsm

/* https://github.com/cirosantilli/linux-kernel-module-cheat#arm-multicore */
.global mystart
mystart:
/* Reset spinlock. */
mov x0, #0
ldr x1, =spinlock
str x0, [x1]
/* Read cpu id into x1. */
mrs x1, mpidr_el1
and x1, x1, #3
cbz x1, 1f
/* Only CPU 1 reaches this point and sets the spinlock. */
mov x0, #1
ldr x1, =spinlock
str x0, [x1]
b .
1:
/* Only CPU 0 reaches this point. */
ldr x0, spinlock
cbz x0, 1b
/* Semihost exit. */
mov x1, #0x26
movk x1, #2, lsl #16
str x1, [sp,#0]
mov x0, #0
str x0, [sp,#8]
mov x1, sp
mov w0, #0x18
hlt 0xf000
spinlock:
.skip 8