/* SPDX-License-Identifier: GPL-2.0-only */ /* * Early initialization code for ARM architecture. * * This file is based off of the OMAP3530/ARM Cortex start.S file from Das * U-Boot, which itself got the file from armboot. */ #include <arch/asm.h> ENTRY(_start) /* * Set the CPU to System mode with IRQ and FIQ disabled. Prefetch/Data * aborts may happen early and crash before the abort handlers are * installed, but at least the problem will show up near the code that * causes it. */ msr cpsr_cxf, #0xdf /* * Initialize the stack to a known value. This is used to check for * stack overflow later in the boot process. */ ldr r0, =_stack ldr r1, =_estack ldr r2, =0xdeadbeef init_stack_loop: str r2, [r0] add r0, #4 cmp r0, r1 bne init_stack_loop /* Set stackpointer in internal RAM to call bootblock main() */ call_bootblock: ldr sp, =_estack /* Set up stack pointer */ ldr r0,=0x00000000 /* * The current design of cpu_info places the * struct at the top of the stack. The number of * words pushed must be at least as large as that * struct. */ push {r0-r2} bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ /* * Use "bl" instead of "b" even though we do not intend to return. * "bl" gets compiled to "blx" if we're transitioning from ARM to * Thumb. However, "b" will not and GCC may attempt to create a * wrapper which is currently broken. */ bl main ENDPROC(_start)