Added running example

riscv/Makefile

@@ -0,0 +1,36 @@
+# Author: Lucas Castro
+# Last modification: sep/2017
+#
+# 	Makefile for creating a raw binary RV32I program for ReonV 
+
+CC=gcc
+AS=as
+OBJCOPY=objcopy
+CROSS=/home/foo/IC/riscv-leon/rv32i/rv32i-gnu/bin/riscv32-unknown-elf-
+CFLAGS=-nostdlib
+OBJCPFLAGS=-O binary -j .text
+
+
+CPPROGRAM=
+
+# Target .s
+%.s : %.c
+		${CROSS}$(CC) -S $(CFLAGS) $(CPPFLAGS) $< -o $@
+
+# Target .o
+%.hex : %.s
+		${CROSS}$(AS) $< -o $@
+
+# Target raw binary
+%.bin : %.hex
+		${CROSS}$(OBJCOPY) $(OBJCPFLAGS)  $< $@
+
+# Inverts target for grmon load (it considers binary is big-endian)
+%.inv : %.bin
+		./swap $< $@
+
+cp-program :
+		cp $(CPPROGRAM) ./repo/designs/leon3-digilent-xc7z020/
+
+clean:
+		rm -rf *.inv *.bin *.o *.log *.jou *.str

riscv/main.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+int mul();
+
+void _start(){
+	int i = 1;
+	int count = 0;
+	do{
+		i = mul(i,4);
+		count++;
+	}while(i < 2500);
+}
+
+int mul(int i,int j){
+	if (i == 0)
+		return 0;
+	return mul(i - 1,j) + j;
+}

riscv/main.s

@@ -0,0 +1,76 @@
+#	.file	"teste.c"
+#	.option nopic
+#	.text
+	#.align	2
+#	.globl	_start
+#	.type	_start, @function
+_start:
+	lui	sp,0x41200
+	add	sp,sp,-32
+	sw	ra,28(sp)
+	sw	s0,24(sp)
+	add	s0,sp,32
+	li	a5,1
+	sw	a5,-20(s0)
+	sw	zero,-24(s0)
+.L2:
+	li	a1,4
+	lw	a0,-20(s0)
+	#call	mul
+	jal	ra,mul
+	sw	a0,-20(s0)
+	lw	a5,-24(s0)
+	add	a5,a5,1
+	####################
+	mv 	x7,a5
+	####################
+	sw	a5,-24(s0)
+	lw	a4,-20(s0)
+	li	a5,4096
+	add	a5,a5,-1597
+	ble	a4,a5,.L2
+	nop
+	lw	ra,28(sp)
+	lw	s0,24(sp)
+	add	sp,sp,32
+
+	#############
+	# Move result to x6 and stop program
+	mv	x6,a4
+	sbreak
+	#############
+	
+	jr	ra
+#	.size	_start, .-_start
+	#.align	2
+#	.globl	mul
+#	.type	mul, @function
+mul:
+	add	sp,sp,-32
+	sw	ra,28(sp)
+	sw	s0,24(sp)
+	add	s0,sp,32
+	sw	a0,-20(s0)
+	sw	a1,-24(s0)
+	lw	a5,-20(s0)
+	bnez	a5,.L4
+	li	a5,0
+	j	.L5
+.L4:
+	lw	a5,-20(s0)
+	add	a5,a5,-1
+	lw	a1,-24(s0)
+	mv	a0,a5
+	#call	mul
+	jal	ra,mul
+	mv	a4,a0
+	lw	a5,-24(s0)
+	add	a5,a4,a5
+.L5:
+	mv	a0,a5
+	lw	ra,28(sp)
+	lw	s0,24(sp)
+	add	sp,sp,32
+	jr	ra
+	.size	mul, .-mul
+	.ident	"GCC: (GNU) 7.1.1 20170509"

riscv/swapendian.c

@@ -0,0 +1,52 @@
+/*	Author: Lucas Castro
+ *  Date:   10/09/2017
+ *
+ * Swaps the "endian" of a binary file (little to big or big to little)
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+int main(int argc, char* argv[]){
+	uint32_t word;
+	uint32_t b0,b1,b2,b3;
+	uint32_t res;
+	unsigned char in_name[30];
+	unsigned char out_name[30];
+	FILE* input;
+	FILE* output;
+
+	if(argc != 3){
+		printf("Usage: ./main <input bin file> <output bin file>\n");
+		return 1;
+	}
+
+	input = fopen(argv[1], "rb");
+	output = fopen(argv[2], "wb");
+
+	if(input == NULL){
+		printf("Error opening input!\n");
+		return 1;
+	}
+	if(output == NULL){
+		fclose(input);
+		printf("Error opening output!\n");
+		return 1;
+	}
+
+	while(fread(&word, sizeof(uint32_t), 1, input)){
+		b0 = (word & 0x000000ff) << 24u;
+		b1 = (word & 0x0000ff00) << 8u;
+		b2 = (word & 0x00ff0000) >> 8u;
+		b3 = (word & 0xff000000) >> 24u;
+
+		res = b0 | b1 | b2 | b3;
+
+		fwrite(&res, sizeof(uint32_t), 1, output);
+	}
+
+	fclose(input);
+	fclose(output);
+
+	return 0;
+}

riscv/to_text.c

@@ -0,0 +1,50 @@
+/*	Author: Lucas Castro
+ *  Date:   10/09/2017
+ *
+ * Reads a binary file and converts its content to readable hexadecimal
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+int main(int argc, char** argv){
+	char word;
+	char res[8];
+	uint8_t i = 0;
+	FILE* input;
+	FILE* output;
+
+	if(argc != 3){
+		printf("Usage: ./<program name> <input bin file> <output readable hex file>\n");
+		return 1;
+	}
+
+	input = fopen(argv[1], "rb");
+	output = fopen(argv[2], "w");
+
+	if(input == NULL){
+		printf("Error opening input!\n");
+		return 1;
+	}
+	if(output == NULL){
+		fclose(input);
+		printf("Error opening output!\n");
+		return 1;
+	}
+
+	while(fread(&word, sizeof(unsigned char), 1, input)){
+		sprintf(res, "%02X", (unsigned char) word & 0xff);
+		fwrite(&res, sizeof(unsigned char), 2, output);
+
+		i++;
+		if(i == 4){
+			fwrite("\n", sizeof(char), 1, output);
+			i = 0;
+		}
+	}
+
+	fclose(input);
+	fclose(output);
+
+	return 0;
+}