Files
ladybird/Kernel/Prekernel/Arch/aarch64/boot.S
2021-09-27 10:17:52 +02:00

35 lines
828 B
ArmAsm

/*
* Copyright (c) 2021, Nico Weber <thakis@chromium.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
// In a specially-named text section so that the linker script can put it first in .text.
.section ".text.first"
.global start
.type start, @function
start:
// Let only core 0 continue, put other cores to sleep.
mrs x13, MPIDR_EL1
and x13, x13, 0xff
cbnz x13, halt
// Let stack start before .text for now.
// 512 kiB (0x80000) of stack are probably not sufficient, especially once we give the other cores some stack too,
// but for now it's ok.
ldr x14, =start
mov sp, x14
b init
.globl wait_cycles
.type wait_cycles, @function
wait_cycles:
Lstart:
// This is probably too fast when caching and branch prediction is turned on.
// FIXME: Make timer-based.
subs x0, x0, #1
bne Lstart
ret