/* * Copyright (c) 2021, Nico Weber * * 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. msr SPSel, #0 //Use the same SP as we descend into EL1 ldr x14, =start mov sp, x14 // Clear BSS. ldr x14, =start_of_bss ldr x15, =size_of_bss_divided_by_8 Lbss_clear_loop: str xzr, [x14], #8 subs x15, x15, #1 bne Lbss_clear_loop b init halt: msr daifset, #2 wfi b halt