I need to use gnu c printf function to send floating point number to semihosting console. The current implementation printf(vsnprintf) is
signed int vsnprintf(char *pStr, size_t length, const char *pFormat, va_list ap)
{
char fill;
unsigned char width;
signed int num = 0;
signed int size = 0;
/* Clear the string */
if (pStr) {
*pStr = 0;
}
/* Phase string */
while (*pFormat != 0 && size < length) {
/* Normal character */
if (*pFormat != '%') {
*pStr++ = *pFormat++;
size++;
}
/* Escaped '%' */
else if (*(pFormat+1) == '%') {
*pStr++ = '%';
pFormat += 2;
size++;
}
/* Token delimiter */
else {
fill = ' ';
width = 0;
pFormat++;
/* Parse filler */
if (*pFormat == '0') {
fill = '0';
pFormat++;
}
/* Parse width */
while ((*pFormat >= '0') && (*pFormat <= '9')) {
width = (width*10) + *pFormat-'0';
pFormat++;
}
/* Check if there is enough space */
if (size + width > length) {
width = length - size;
}
/* Parse type */
switch (*pFormat) {
case 'd':
case 'i': num = PutSignedInt(pStr, fill, width, va_arg(ap, signed int)); break;
case 'u': num = PutUnsignedInt(pStr, fill, width, va_arg(ap, unsigned int)); break;
case 'x': num = PutHexa(pStr, fill, width, 0, va_arg(ap, unsigned int)); break;
case 'X': num = PutHexa(pStr, fill, width, 1, va_arg(ap, unsigned int)); break;
case 's': num = PutString(pStr, va_arg(ap, char *)); break;
case 'c': num = PutChar(pStr, va_arg(ap, unsigned int)); break;
default:
return EOF;
}
pFormat++;
pStr += num;
size += num;
}
}
/* NULL-terminated (final \0 is not counted) */
if (size < length) {
*pStr = 0;
}
else {
*(--pStr) = 0;
size--;
}
return size;
}
Any help to implement 'f' format specifier is greatly appreciated