#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 picorv32_retirq_insn()