摘要： 在U-Boot源码的start.s中有着如下红色部分语句：.globl _start_start: b start_code ldr pc, _undefined_instruction ldr pc, _software_interrupt ldr pc, _prefetch_abort ldr pc, _data_abort ldr pc, _not_used ldr pc, _irq ldr pc, _fiq_undefined_instruction: .word undefined_instruction_software_interrupt: .word software_inte 阅读全文