#include "tl2cdr.h"

.globl _prog_start
.globl _rv32i_plic_handle

.section .text.init, "ax", %progbits

#if 0
#其他代码全部使用RV32E编译，仅此代码采用 RV32I 编译，故而可以使用x0, x16~x31寄存器
#为了方便，不再使用ABI中的别名，直接使用x0, x16~x31；x1~x15使用ABI中定义的别名
#endif

_prog_start:
	li		x16, 0
	
	mv 		x17, a0 # plic_claim
	mv 		x18, a1 # flag_intTxEnd
	mv 		x19, a2 # flag_intRxError
	mv 		x20, a3 # flag_intRxStart
	mv 		x21, a4 # flag_intRxEnd
	mv 		x22, x0

	#lui 	x23, %hi(_rv32i_plic_handle)
	#lw		x24, %lo(_rv32i_plic_handle)(x23)
	
	la		x24, _rv32i_plic_handle
	
	li		x25, 1
	li		x26, 0
	li		x27, 0
	li		x28, CDR_INT_TXEND
	li		x29, CDR_INT_RXERROR
	li		x30, CDR_INT_RXSTART
	li		x31, CDR_INT_RXSTART


    mv		a0, x24

	li		x23, 0
	li		x24, 0
    ret

	.balign 32
_rv32i_plic_handle:
#if 0  	/*RV32的核心自动禁用中断，无需手动禁用*/
	csrr 	x16, mstatus         	# 读取 mstatus 寄存器
    andi 	x16, x16, ~(1 << 3)    	# 清除 MIE 位 (全局中断禁用)
    csrw 	mstatus, x16           	# 写回 mstatus 寄存器
#endif

	lw 		x23, 0(x17)    			# x23 = *plic_claim
	sw  	x23, 0(x17)				# *plic_claim = x23

	#li 		x25, 1
#if 0
	li		x24, CDR_INT_TXEND
	bne 	x23, x24, 1f   			#_if (x23 != x24) goto 1f
	sw		x25, 0(x18)				#_else
	j 		4f

1:
	li  	x24, CDR_INT_RXERROR
	bne 	x23, x24, 2f   			#_if (x23 != x24) goto 2f
	sw		x25, 0(x19)				#_else
	j 		4f

2:
	li  	x24, CDR_INT_RXSTART
	bne 	x23, x24, 3f			#_if (x23 != x24) goto 3f
	sw		x25, 0(x20)				#_else
	j 		4f

3:
	li  	x24, CDR_INT_RXEND
	bne 	x23, x24, 4f			#_if (x23 != x24) goto 4f
	sw		x25, 0(x21)				#_else
#else
	bne 	x23, x28, 1f   			#_if (x23 != x24) goto 1f
	sw		x25, 0(x18)				#_else
	j 		4f

1:
	bne 	x23, x29, 2f   			#_if (x23 != x24) goto 2f
	sw		x25, 0(x19)				#_else
	j 		4f

2:
	bne 	x23, x30, 3f			#_if (x23 != x24) goto 3f
	sw		x25, 0(x20)				#_else
	j 		4f

3:
	bne 	x23, x31, 4f			#_if (x23 != x24) goto 4f
	sw		x25, 0(x21)				#_else
#endif
4:
#if 0  /*RV32的核心自动启动中断，无需手动启用*/
	csrr 	x16, mstatus
	ori  	x16, x16, 1<<3
	csrw 	mstatus, x16
#endif
	mret