eb001/tb/sw/src/slvStartup.S

#include "custom_ops.S"


.extern main
.globl _prog_start
.section .text.init


_prog_start:
	li sp, 0
	picorv32_maskirq_insn(zero, zero)

	call main


	ecall


.balign 32
.section .trap_entry, "ax", %progbits
trap_entry:
	# q0 return address
	# q1 bitmask of all IRQ to be handled, may be more than one IRQ 
	# q2 q3 unused, can be use as temp storage register

	# q寄存器已经禁用， Without the q-registers, the irq return address will be stored in x3 (gp) and the IRQ bitmask in x4 (tp),

	# io.interrupt(0) := intTxError
	# io.interrupt(1) := intRxError
	# io.interrupt(2) := intRxStart
	# io.interrupt(3) := intRxEnd


	or sp, sp, x4

	andi x4, x4, 0x2
	beqz x4, 1f
	li x4, 0
	sw x3, 0x400(x0)

	1:
	picorv32_retirq_insn()