s3c2440 串口 裸机驱动 实现printf函数功能

#include "uart_driver.h" void s3c2440_putchar(char c) { switch(c) { case '\n': uart_putchar('\r'); break; case '\b': uart_putchar('\b'); uart_putchar(' '); break; default: break; } uart_putchar(c); } char s3c2440_getchar(void) { char c = uart_getchar(); return c=='\r'?'\n':c; } void s3c2440_puts(const char *str) { while(*str) s3c2440_putchar(*str++); } void s3c2440_putint_1(int num) { int n,m; if(num==0) return; n = num%10; m = num/10; s3c2440_putint_1(m); s3c2440_putchar(n+'0'); } void s3c2440_putint(int num) { if(num==0) s3c2440_putchar('0'); else s3c2440_putint_1(num); } int strlen(const char *str) { const char *s = str; while(*str++) ; return str - s - 1; } void inverse(char *str) { int len,i,temp; len = strlen(str); for(i=0;i<len/2;i++) { temp = str[i]; str[i] = str[len-i-1]; str[len-i-1] = temp; } } /********************************** void s3c2440_putint(int num) { char str[11]; int i = 0; do{ str[i++] = num%10 + '0'; num/=10; }while(num!=0); str[i] = 0; inverse(str); s3c2440_puts(str); } **********************************/ void s3c2440_putchar_hex(char c) { char hex[] = "0123456789ABCDEF"; s3c2440_putchar(hex[(c>>4 & 0xF)]); s3c2440_putchar(hex[(c>>0 & 0xF)]); } void s3c2440_putint_hex(int num) { s3c2440_putchar_hex(num>>24 & 0xFF); s3c2440_putchar_hex(num>>16 & 0xFF); s3c2440_putchar_hex(num>>8 & 0xFF); s3c2440_putchar_hex(num>>0 & 0xFF); } int s3c2440_printf(const char *format,...) { char c; int total = 0; int *addr = (int*)&format; while((c=*format)!=0) { if(c=='%') { format++; switch(*format) { case 's': total++; s3c2440_puts(*(char**)(++addr)); break; case 'd': total++; s3c2440_putint(*(int*)(++addr)); break; case 'c': total++; s3c2440_putchar(*(char*)(++addr)); break; case 'x': total++; s3c2440_putint_hex(*(int*)(++addr)); break; default: s3c2440_putchar('%'); s3c2440_putchar(*format); } } else { s3c2440_putchar(c); } format++; } return total; }