| /* 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 tegra124_main |
| ENDPROC(_start) |