feat(io): implement printf and strlen

README.md

@@ -1,5 +1,3 @@
 # rivos
 
-A small educational operating system targeting the RISC-V architecture.
-
-Focused on simplicity, low-level exploration, and learning by building.
+This toy os is made following the [OS in 1,000 lines](https://1000os.seiya.me/en/) project.

include/io.h

@@ -8,6 +8,7 @@
 #define va_end __builtin_va_end
 #define va_arg __builtin_va_arg
 
-void kprintf(const char *fmt, ...);
+void r_printf(const char *fmt, ...);
+size_t r_strlen(const char *str);
 
 #endif

include/kernel.h

@@ -1,11 +1,9 @@
 #ifndef RIVOS_KERNEL_H
 #define RIVOS_KERNEL_H
 
-typedef struct sbiret {
+typedef struct sbiret_s {
 	long error;
 	long value;
 } sbiret_s;
 
-void kputchar(char ch);
-
 #endif

include/memory.h

@@ -1,10 +0,0 @@
-#ifndef RIVOS_MEMORY_H
-#define RIVOS_MEMORY_H
-
-#include "types.h"
-
-void *kmemset(void *buf, char c, size_t n);
-
-void *kmemcpy(void *dst, const void *src, size_t n);
-
-#endif

include/string.h

@@ -1,15 +0,0 @@
-#ifndef RIVOS_STRING_H
-#define RIVOS_STRING_H
-
-#include "types.h"
-
-/**
- * This is not a safe function, check dst size
- */
-char *kstrcpy(char *dst, const char *src);
-
-size_t kstrlen(const char *str);
-
-int kstrcmp(const char *s1, const char *s2);
-
-#endif

include/types.h

@@ -5,13 +5,7 @@
  * Define our standard types
  */
 typedef unsigned char u8;
-typedef unsigned short u16;
 typedef unsigned int u32;
-typedef unsigned long long u64;
 typedef u32 size_t;
 
-#define true 1
-#define false 0
-#define NULL ((void *)0)
-
 #endif

run.sh

@@ -18,9 +18,7 @@ CFLAGS="-std=c11 -O2 -g3 -Wall -Wextra --target=riscv32-unknown-elf -fuse-ld=lld
 
 $CC $CFLAGS -Wl,-Tkernel.ld -Wl,-Map=kernel.map -o kernel.elf \
     src/kernel.c \
-    src/io.c \
-    src/memory.c \
-    src/string.c
+    src/io.c
 
 # Run QEMU
 # -machine virt: generic riscv platform

src/io.c

@@ -1,15 +1,14 @@
 #include "../include/io.h"
-#include "../include/string.h"
 
-void kputchar(char ch);
+void k_putchar(char ch);
 
-void kprintf(const char *fmt, ...) {
+void r_printf(const char *fmt, ...) {
 	va_list args;
 	va_start(args, fmt);
 
 	while (*fmt) {
 		if (*fmt != '%') {
-			kputchar(*fmt);
+			k_putchar(*fmt);
 			fmt++;
 			continue;
 		}
@@ -19,13 +18,13 @@ void kprintf(const char *fmt, ...) {
 		switch (*fmt) {
 			case '\0': {
 				/* Simply print the char */
-				kputchar('%');
+				k_putchar('%');
 
 				goto end;
 			}
 			case '%': {
 				/* Print '%' */
-				kputchar('%');
+				k_putchar('%');
 
 				break;
 			}
@@ -33,7 +32,7 @@ void kprintf(const char *fmt, ...) {
 				/* Print a NULL-terminated string */
 				const char *s = va_arg(args, const char *);
 				while (*s) {
-					kputchar(*s);
+					k_putchar(*s);
 					s++;
 				}
 
@@ -44,7 +43,7 @@ void kprintf(const char *fmt, ...) {
 				int value = va_arg(args, int);
 				unsigned magnitude = value;
 				if (value < 0) {
-					kputchar('-');
+					k_putchar('-');
 					magnitude = -magnitude;
 				}
 
@@ -54,9 +53,12 @@ void kprintf(const char *fmt, ...) {
 				}
 
 				while (divisor > 0) {
-					kputchar('0' + magnitude / divisor);
+					k_putchar('0' + magnitude);
+					k_putchar('0' + magnitude / divisor);
 					magnitude %= divisor;
+					k_putchar('0' + magnitude);
 					divisor /= 10;
+					k_putchar('0' + magnitude);
 				}
 
 				break;
@@ -67,14 +69,14 @@ void kprintf(const char *fmt, ...) {
 				for (int i = 7; i >= 0; --i) {
 					unsigned nibble = (value >> (i * 4)) & 0xF;
 					/* From a char array we get the nibble position */
-					kputchar("0123456789ABCDEF"[nibble]);
+					k_putchar("0123456789ABCDEF"[nibble]);
 				}
 			}
 			default: {
 				const char *str = "NOT IMPLEMENTED";
-				size_t len = kstrlen(str);
+				size_t len = r_strlen(str);
 				for (size_t i = 0; i < len; ++i) {
-					kputchar(str[i]);
+					k_putchar(str[i]);
 				}
 			}
 		}
@@ -85,3 +87,14 @@ void kprintf(const char *fmt, ...) {
 end:
 	va_end(args);
 }
+
+size_t r_strlen(const char *str) {
+	size_t len = 0;
+
+	while (*str) {
+		len++;
+		str++;
+	}
+
+	return len;
+}

src/kernel.c

@@ -1,6 +1,6 @@
 #include "../include/kernel.h"
 #include "../include/io.h"
-#include "../include/memory.h"
+#include "../include/types.h"
 
 extern char __bss[], __bss_end[], __stack_top[];
 
@@ -14,7 +14,7 @@ extern char __bss[], __bss_end[], __stack_top[];
  * a0 returns and error code
  */
 sbiret_s sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long fid, long eid) {
-	register long a0 __asm__("a0") = arg0;
+	register long a0 __asm("a0") = arg0;
 	register long a1 __asm__("a1") = arg1;
 	register long a2 __asm__("a2") = arg2;
 	register long a3 __asm__("a3") = arg3;
@@ -31,18 +31,27 @@ sbiret_s sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4, long ar
 	return (sbiret_s){.error = a0, .value = a1};
 }
 
-void kputchar(char ch) {
+void k_putchar(char ch) {
 	sbi_call(ch, 0, 0, 0, 0, 0, 0, 1);
 }
 
+void *k_memset(void *buf, char c, size_t n) {
+	u8 *p = (u8 *)buf;
+	while (n--) {
+		*p++ = c;
+	}
+
+	return buf;
+}
+
 /* Kernel main */
 void kernel_main(void) {
 	/* Usually it is not required */
-	kmemset(__bss, 0, __bss_end - __bss);
+	k_memset(__bss, 0, __bss_end - __bss);
 
 	/* Start here */
-	kprintf("%s, %s\n", "Hello", "world!");
-	kprintf("3 + 4 = %d\n", 3 + 4);
+	r_printf("%s, %s\n", "Hello", "world!");
+	r_printf("3 + 4 = %d\n", 3 + 4);
 
 	for (;;) {
 		__asm__ __volatile__("wfi");

src/memory.c

@@ -1,21 +0,0 @@
-#include "../include/memory.h"
-
-void *kmemset(void *buf, char c, size_t n) {
-	u8 *p = (u8 *)buf;
-	while (n--) {
-		*p++ = c;
-	}
-
-	return buf;
-}
-
-void *kmemcpy(void *dst, const void *src, size_t n) {
-	u8 *dest = (u8 *)dst;
-	const u8 *source = (u8 *)src;
-
-	while (n--) {
-		*dest++ = *source++;
-	}
-
-	return dst;
-}

src/string.c

@@ -1,29 +0,0 @@
-#include "../include/string.h"
-
-char *kstrcpy(char *dst, const char *src) {
-	while (*src) {
-		*dst = *src;
-		src++;
-	}
-
-	return dst;
-}
-
-size_t kstrlen(const char *str) {
-	size_t len = 0;
-
-	while (*str) {
-		len++;
-		str++;
-	}
-
-	return len;
-}
-
-int kstrcmp(const char *s1, const char *s2) {
-	/**
-	 * TODO
-	 */
-
-	return 0;
-}