Create __iob for picolibc

Picolibc requires __iob array for its IO functions

This commit creates such array with dummy functions
using putchar/readchar from console.c

To prevent name conflicts printf and others were
removed from console.c

Also putchar had to be renamed to base_putchar

litex/soc/software/libbase/console.c

@@ -5,8 +5,6 @@
 
 #include <generated/csr.h>
 
-FILE *stdin, *stdout, *stderr;
-
 static console_write_hook write_hook;
 static console_read_hook read_hook;
 static console_read_nonblock_hook read_nonblock_hook;
@@ -23,13 +21,13 @@ void console_set_read_hook(console_read_hook r, console_read_nonblock_hook rn)
 }
 
 #ifdef CSR_UART_BASE
-int putchar(int c)
+int base_putchar(int c)
 {
 	uart_write(c);
 	if(write_hook != NULL)
 		write_hook(c);
 	if (c == '\n')
-		putchar('\r');
+		base_putchar('\r');
 	return c;
 }
 
@@ -51,7 +49,7 @@ int readchar_nonblock(void)
 
 #else
 
-int putchar(int c)
+int base_putchar(int c)
 {
 	if(write_hook != NULL)
 		write_hook(c);
@@ -73,13 +71,6 @@ int readchar_nonblock(void)
 
 #endif
 
-int puts(const char *s)
-{
-	putsnonl(s);
-	putchar('\n');
-	return 1;
-}
-
 void putsnonl(const char *s)
 {
 	while(*s) {
@@ -88,150 +79,3 @@ void putsnonl(const char *s)
 	}
 }
 
-int skip_atoi(const char **s)
-{
-	int i=0;
-
-	while (isdigit(**s))
-		i = i*10 + *((*s)++) - '0';
-	return i;
-}
-
-char *number(char *buf, char *end, unsigned long num, int base, int size, int precision, int type)
-{
-	char c,sign,tmp[66];
-	const char *digits;
-	static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
-	static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
-	int i;
-
-	digits = (type & PRINTF_LARGE) ? large_digits : small_digits;
-	if (type & PRINTF_LEFT)
-		type &= ~PRINTF_ZEROPAD;
-	if (base < 2 || base > 36)
-		return NULL;
-	c = (type & PRINTF_ZEROPAD) ? '0' : ' ';
-	sign = 0;
-	if (type & PRINTF_SIGN) {
-		if ((signed long) num < 0) {
-			sign = '-';
-			num = - (signed long) num;
-			size--;
-		} else if (type & PRINTF_PLUS) {
-			sign = '+';
-			size--;
-		} else if (type & PRINTF_SPACE) {
-			sign = ' ';
-			size--;
-		}
-	}
-	if (type & PRINTF_SPECIAL) {
-		if (base == 16)
-			size -= 2;
-		else if (base == 8)
-			size--;
-	}
-	i = 0;
-	if (num == 0)
-		tmp[i++]='0';
-	else while (num != 0) {
-		tmp[i++] = digits[num % base];
-		num = num / base;
-	}
-	if (i > precision)
-		precision = i;
-	size -= precision;
-	if (!(type&(PRINTF_ZEROPAD+PRINTF_LEFT))) {
-		while(size-->0) {
-			if (buf < end)
-				*buf = ' ';
-			++buf;
-		}
-	}
-	if (sign) {
-		if (buf < end)
-			*buf = sign;
-		++buf;
-	}
-	if (type & PRINTF_SPECIAL) {
-		if (base==8) {
-			if (buf < end)
-				*buf = '0';
-			++buf;
-		} else if (base==16) {
-			if (buf < end)
-				*buf = '0';
-			++buf;
-			if (buf < end)
-				*buf = digits[33];
-			++buf;
-		}
-	}
-	if (!(type & PRINTF_LEFT)) {
-		while (size-- > 0) {
-			if (buf < end)
-				*buf = c;
-			++buf;
-		}
-	}
-	while (i < precision--) {
-		if (buf < end)
-			*buf = '0';
-		++buf;
-	}
-	while (i-- > 0) {
-		if (buf < end)
-			*buf = tmp[i];
-		++buf;
-	}
-	while (size-- > 0) {
-		if (buf < end)
-			*buf = ' ';
-		++buf;
-	}
-	return buf;
-}
-
-/**
- * vscnprintf - Format a string and place it in a buffer
- * @buf: The buffer to place the result into
- * @size: The size of the buffer, including the trailing null space
- * @fmt: The format string to use
- * @args: Arguments for the format string
- *
- * The return value is the number of characters which have been written into
- * the @buf not including the trailing '\0'. If @size is <= 0 the function
- * returns 0.
- *
- * Call this function if you are already dealing with a va_list.
- * You probably want scnprintf() instead.
- */
-int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
-{
-        size_t i;
-
-	i=vsnprintf(buf,size,fmt,args);
-	return (i >= size) ? (size - 1) : i;
-}
-
-#define PRINTF_BUFFER_SIZE 256
-
-int vprintf(const char *fmt, va_list args)
-{
-	int len;
-	char outbuf[PRINTF_BUFFER_SIZE];
-	len = vscnprintf(outbuf, sizeof(outbuf), fmt, args);
-	outbuf[len] = 0;
-	putsnonl(outbuf);
-	return len;
-}
-
-int printf(const char *fmt, ...)
-{
-	int len;
-	va_list args;
-	va_start(args, fmt);
-	len = vprintf(fmt, args);
-	va_end(args);
-	return len;
-}

litex/soc/software/libc/Makefile

@@ -1,6 +1,25 @@
 include ../include/generated/variables.mak
 include $(SOC_DIRECTORY)/software/common.mak
 
+pINCLUDES = -I$(PICOLIBC_DIRECTORY)/newlib/libc/tinystdio \
+            -I$(PICOLIBC_DIRECTORY)/newlib/libc/include \
+            -I$(SOC_DIRECTORY)/software/include \
+            -I$(BUILDINC_DIRECTORY)/../libc \
+            -I$(BUILDINC_DIRECTORY) \
+            -I$(CPU_DIRECTORY)
+
+pCOMMONFLAGS = -Os $(CPUFLAGS) -g3 -fomit-frame-pointer -Wall -fno-builtin -nostdlib -fno-stack-protector $(pINCLUDES)
+pCFLAGS = $(pCOMMONFLAGS) -fexceptions -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes
+
+all: libc.a iob.c.o
+
+iob.c.o:
+	$(CC) \
+		-c $(LIBC_DIRECTORY)/iob.c \
+		-o $@ \
+		$(pCFLAGS)
+	$(AR) csr libc.a iob.c.o
+
 libc.a:
 	meson $(PICOLIBC_DIRECTORY) \
 		-Dmultilib=false \

litex/soc/software/libc/iob.c

@@ -0,0 +1,30 @@
+#include <base/console.h>
+#include <stdio.h>
+//#include <sys/cdefs.h>
+
+
+static int
+dummy_putc(char c, FILE *file)
+{
+	(void) file;
+	return base_putchar(c);
+}
+
+static int
+dummy_getc(FILE *file)
+{
+	(void) file;
+	return readchar();
+}
+
+static int
+dummy_flush(FILE *file)
+{
+	(void) file;
+	return 0;
+}
+
+static FILE __stdio = FDEV_SETUP_STREAM(dummy_putc, dummy_getc, dummy_flush, _FDEV_SETUP_RW);
+
+FILE *const __iob[3] = { &__stdio, &__stdio, &__stdio };
+