os-core/kernel/aarch64/boot.S

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652 B
ArmAsm
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2019-12-01 22:57:02 +01:00
#include "aarch64_reg.h"
.globl _start
_start:
mrs x0, mpidr_el1 /* Check CPU ID */
mov x1, 0xC1000000
bic x0, x0, x1
cbz x0, set_el
idle:
b idle
set_el:
/* check current exception level */
bl aarch64_get_el
cmp x0, 0x03
bne set_stack
/* set SCTRL_EL1 */
ldr x0, =SCTLR_VALUE_MMU_DISABLED
msr sctlr_el1, x0
/* set HCR_EL2 */
ldr x0, =HCR_VALUE
msr hcr_el2, x0
/* set SCR_EL3 */
ldr x0, =SCR_VALUE
msr scr_el3, x0
/* set SPSR_EL3 */
ldr x0, =SPSR_VALUE
msr spsr_el3, x0
/* set elr_el3 */
adr x0, set_stack
msr elr_el3, x0
eret
set_stack:
ldr x30, =stack_ptr /* defined in aarch64.ld */
mov sp, x30
bl k_main