Add kernel libc

build/Makefile

@@ -64,13 +64,16 @@ endif
 # FILES AND DIRS #
 ##################
 
+rwildcard=$(foreach d,$(wildcard $(1:=/*)),$(call rwildcard,$d,$2) $(filter $(subst *,%,$2),$d))
+
 BUILD_DIR = .
 OBJ_DIR = $(BUILD_DIR)/obj
 
 SRC_DIR = ../src
 INCLUDE_DIR = $(BUILD_DIR)/../include
+K_LIBC_DIR = $(SRC_DIR)/kernel/k_libc
 
-KERNEL_C_FILES = $(wildcard $(SRC_DIR)/kernel/*.c)
+KERNEL_C_FILES = $(call rwildcard, $(SRC_DIR)/kernel, *.c)
 LIBC_C_FILES   = $(wildcard $(SRC_DIR)/libc/*.c)
 KERNEL_S_FILES = $(wildcard $(SRC_DIR)/$(ARCH)/*.S)
 
@@ -97,11 +100,11 @@ clean:
 # Compile C files
 $(OBJ_DIR)/kernel/%_c.o: $(SRC_DIR)/kernel/%.c
 	@mkdir -p $(@D)
-	$(CC) $(CFLAGS) -I$(INCLUDE_DIR) -c $< -o $@
+	$(CC) $(CFLAGS) -I$(INCLUDE_DIR) -I$(K_LIBC_DIR) -c $< -o $@
 
 $(OBJ_DIR)/libc/%_c.o: $(SRC_DIR)/libc/%.c
 	@mkdir -p $(@D)
-	$(CC) $(CFLAGS) -I$(INCLUDE_DIR) -c $< -o $@
+	$(CC) $(CFLAGS) -I$(INCLUDE_DIR) -I$(K_LIBC_DIR) -c $< -o $@
 
 # Compile S files
 $(OBJ_DIR)/$(ARCH)/%_S.o: $(SRC_DIR)/$(ARCH)/%.S

include/stdio.h

@@ -8,15 +8,10 @@
 extern "C" {
 #endif
 
-char getc(void);
-void putc(char c);
+char getchar(void);
+void putcchar(char c);
 void puts(const char * s);
 
-uint32_t strlen(char * s);
-void strrev(char * s);
-void itoa(int n, char * s);
-
-
 #ifdef __cplusplus
 }
 #endif

include/string.h

@@ -8,7 +8,6 @@ extern "C" {
 #endif
 
 uint32_t strlen(char * s);
-void strrev(char * s);
 
 #ifdef __cplusplus
 }

src/kernel/k_libc/k_printf.c

@@ -0,0 +1,192 @@
+/*
+  Copyright 2001-2019 Georges Menie
+  https://www.menie.org/georges/embedded/small_printf_source_code.html
+  stdarg version contributed by Christian Ettinger
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+
+#include "k_stdio.h"
+
+#include <stdarg.h>
+
+static void printchar(char **str, int c)
+{
+	if (str) {
+		**str = c;
+		++(*str);
+	}
+	else (void)k_putchar(c);
+}
+
+#define PAD_RIGHT 1
+#define PAD_ZERO 2
+
+static int prints(char **out, const char *string, int width, int pad)
+{
+	register int pc = 0, padchar = ' ';
+
+	if (width > 0) {
+		register int len = 0;
+		register const char *ptr;
+		for (ptr = string; *ptr; ++ptr) ++len;
+		if (len >= width) width = 0;
+		else width -= len;
+		if (pad & PAD_ZERO) padchar = '0';
+	}
+	if (!(pad & PAD_RIGHT)) {
+		for ( ; width > 0; --width) {
+			printchar (out, padchar);
+			++pc;
+		}
+	}
+	for ( ; *string ; ++string) {
+		printchar (out, *string);
+		++pc;
+	}
+	for ( ; width > 0; --width) {
+		printchar (out, padchar);
+		++pc;
+	}
+
+	return pc;
+}
+
+/* the following should be enough for 32 bit int */
+#define PRINT_BUF_LEN 12
+
+static int printi(char **out, int i, int b, int sg, int width, int pad, int letbase)
+{
+	char print_buf[PRINT_BUF_LEN];
+	register char *s;
+	register int t, neg = 0, pc = 0;
+	register unsigned int u = i;
+
+	if (i == 0) {
+		print_buf[0] = '0';
+		print_buf[1] = '\0';
+		return prints (out, print_buf, width, pad);
+	}
+
+	if (sg && b == 10 && i < 0) {
+		neg = 1;
+		u = -i;
+	}
+
+	s = print_buf + PRINT_BUF_LEN-1;
+	*s = '\0';
+
+	while (u) {
+		t = u % b;
+		if( t >= 10 )
+			t += letbase - '0' - 10;
+		*--s = t + '0';
+		u /= b;
+	}
+
+	if (neg) {
+		if( width && (pad & PAD_ZERO) ) {
+			printchar (out, '-');
+			++pc;
+			--width;
+		}
+		else {
+			*--s = '-';
+		}
+	}
+
+	return pc + prints (out, s, width, pad);
+}
+
+static int print(char **out, const char *format, va_list args )
+{
+	register int width, pad;
+	register int pc = 0;
+	char scr[2];
+
+	for (; *format != 0; ++format) {
+		if (*format == '%') {
+			++format;
+			width = pad = 0;
+			if (*format == '\0') break;
+			if (*format == '%') goto out;
+			if (*format == '-') {
+				++format;
+				pad = PAD_RIGHT;
+			}
+			while (*format == '0') {
+				++format;
+				pad |= PAD_ZERO;
+			}
+			for ( ; *format >= '0' && *format <= '9'; ++format) {
+				width *= 10;
+				width += *format - '0';
+			}
+			if( *format == 's' ) {
+				register char *s = (char *)va_arg( args, int );
+				pc += prints (out, s?s:"(null)", width, pad);
+				continue;
+			}
+			if( *format == 'd' ) {
+				pc += printi (out, va_arg( args, int ), 10, 1, width, pad, 'a');
+				continue;
+			}
+			if( *format == 'x' ) {
+				pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'a');
+				continue;
+			}
+			if( *format == 'X' ) {
+				pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'A');
+				continue;
+			}
+			if( *format == 'u' ) {
+				pc += printi (out, va_arg( args, int ), 10, 0, width, pad, 'a');
+				continue;
+			}
+			if( *format == 'c' ) {
+				/* char are converted to int then pushed on the stack */
+				scr[0] = (char)va_arg( args, int );
+				scr[1] = '\0';
+				pc += prints (out, scr, width, pad);
+				continue;
+			}
+		}
+		else {
+		out:
+			printchar (out, *format);
+			++pc;
+		}
+	}
+	if (out) **out = '\0';
+	va_end( args );
+	return pc;
+}
+
+int k_printf(const char *format, ...)
+{
+        va_list args;
+
+        va_start( args, format );
+        return print( 0, format, args );
+}
+
+int k_sprintf(char *out, const char *format, ...)
+{
+        va_list args;
+
+        va_start( args, format );
+        return print( &out, format, args );
+}

src/kernel/k_libc/k_stdio.c

@@ -0,0 +1,8 @@
+#include "k_stdio.h"
+
+#include "../uart.h"
+
+void k_putchar(char c)
+{
+    uart_putc(c);
+}

src/kernel/k_libc/k_stdio.h

@@ -0,0 +1,9 @@
+#ifndef __K_STDIO_H__
+#define __K_STDIO_H__
+
+void k_putchar(char c);
+
+int k_printf(const char *format, ...);
+int k_sprintf(char *out, const char *format, ...);
+
+#endif // __K_STDIO_H__

src/kernel/k_libc/k_stdlib.c

@@ -0,0 +1,30 @@
+#include "k_stdlib.h"
+#include "k_string.h"
+
+static void strrev(char * s)
+{
+    uint32_t i, j;
+    char c;
+
+    for (i = 0, j = k_strlen(s)-1; i<j; i++, j--) {
+        c = s[i];
+        s[i] = s[j];
+        s[j] = c;
+    }
+}
+
+void k_itoa(int n, char * s)
+{
+    int i, sign;
+
+    if ((sign = n) < 0)
+        n = -n;
+    i = 0;
+    do {
+        s[i++] = n % 10 + '0';
+    } while ((n /= 10) > 0);
+    if (sign < 0)
+        s[i++] = '-';
+    s[i] = '\0';
+    strrev(s);
+}

src/kernel/k_libc/k_stdlib.h

@@ -0,0 +1,6 @@
+#ifndef __K_STDLIB_H__
+#define __K_STDLIB_H__
+
+void k_itoa(int n, char * s);
+
+#endif // __K_STDLIB_H__

src/kernel/k_libc/k_string.c

@@ -0,0 +1,11 @@
+#include "k_string.h"
+
+uint32_t k_strlen(char * s)
+{
+    uint32_t n = 0;
+    while (s[n] != '\0')
+    {
+        n++;
+    }
+    return n;
+}

src/kernel/k_libc/k_string.h

@@ -0,0 +1,8 @@
+#ifndef __K_STRING_H__
+#define __K_STRING_H__
+
+#include <stdint.h>
+
+uint32_t k_strlen(char * s);
+
+#endif // __K_STRING_H__

src/libc/stdio.c

@@ -3,16 +3,16 @@
 /* For the moment standard IO uses UART methods ... */
 #include "../kernel/uart.h"
 
-char getc(void) {
+char getchar(void) {
     return uart_getc();
 }
 
-void putc(char c) {
+void putchar(char c) {
     uart_putc(c);
 }
 
 void puts(const char * str) {
     int i;
     for (i = 0; str[i] != '\0'; i ++)
-        putc(str[i]);
+        putchar(str[i]);
 }

src/libc/stdlib.c

@@ -1,18 +1,7 @@
 #include <stdlib.h>
-#include <string.h>
+#include <k_stdlib.h>
 
 void itoa(int n, char * s)
 {
-    int i, sign;
-
-    if ((sign = n) < 0)
-        n = -n;
-    i = 0;
-    do {
-        s[i++] = n % 10 + '0';
-    } while ((n /= 10) > 0);
-    if (sign < 0)
-        s[i++] = '-';
-    s[i] = '\0';
-    strrev(s);
+    return k_itoa(n, s);
 }

src/libc/string.c

@@ -1,26 +1,7 @@
 #include <string.h>
-
-#include <stdint.h>
+#include <k_string.h>
 
 uint32_t strlen(char * s)
 {
-    uint32_t n = 0;
-    while (*s != '\0')
-    {
-        s++;
-        n++;
-    }
-    return n;
-}
-
-void strrev(char * s)
-{
-    uint32_t i, j;
-    char c;
-
-    for (i = 0, j = strlen(s)-1; i<j; i++, j--) {
-        c = s[i];
-        s[i] = s[j];
-        s[j] = c;
-    }
-}
+    return k_strlen(s);
+}