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#include <stdint.h>
#include "semihosting.h"
size_t strlen(const char *buf)
{
int len = 0;
while (buf[len])
len++;
return len;
}
#define O_RDONLY 0
#define O_WRONLY 1
#define O_RDWR 2
#define O_RDWR 2
#define O_TRUNC 0x0800
int errno;
/* These semihosting functions came from the Freedom Metal source. */
static int open(const char *name, int flags, int mode) {
int semiflags = 0;
switch (flags & (O_RDONLY | O_WRONLY | O_RDWR)) {
case O_RDONLY:
semiflags = 0; /* 'r' */
break;
case O_WRONLY:
if (flags & O_TRUNC)
semiflags = 4; /* 'w' */
else
semiflags = 8; /* 'a' */
break;
default:
if (flags & O_TRUNC)
semiflags = 6; /* 'w+' */
else
semiflags = 10; /* 'a+' */
break;
}
volatile semihostparam_t arg = {.param1 = (uintptr_t)name,
.param2 = (uintptr_t)semiflags,
.param3 = (uintptr_t)strlen(name)};
int ret = (int)semihost_call_host(SEMIHOST_SYS_OPEN, (uintptr_t)&arg);
if (ret == -1)
errno = semihost_call_host(SEMIHOST_SYS_ERRNO, 0);
return ret;
}
static ssize_t write(int file, const void *ptr, size_t len)
{
volatile semihostparam_t arg = {.param1 = (uintptr_t)file,
.param2 = (uintptr_t)ptr,
.param3 = (uintptr_t)len};
ssize_t ret =
(ssize_t)semihost_call_host(SEMIHOST_SYS_WRITE, (uintptr_t)&arg);
return (len - ret);
}
int main()
{
char *filename = NULL;
const char *message = "Hello, world!\n";
const char *message2 = "Do re mi fa so la ti do!\n";
int fd;
begin:
fd = open(filename, O_WRONLY, 0644);
write(fd, message, strlen(message));
write(1, message2, strlen(message2));
}
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