int dos_rename(const char *oldpath, const char *newpath)
{
/* This function isn't fully atomic like on Unix,
but it's as close as I know how to do under DOS. */
struct trap_state ts;
oskit_addr_t dos_buf_phys = (oskit_addr_t)kvtophys(dos_buf);
int err;
init_ts(&ts);
/* Put the oldpath in the first half of dos_buf,
and the newpath in the second half. */
if ((strlen(oldpath)+1 > DOS_BUF_SIZE/2)
|| (strlen(newpath)+1 > DOS_BUF_SIZE/2))
{ errno = E2BIG; return -1; }
strcpy(dos_buf, oldpath);
strcpy(dos_buf+DOS_BUF_SIZE/2, newpath);
/* Try once to rename the file. */
ts.trapno = 0x21;
ts.eax = 0x5600;
ts.v86_ds = dos_buf_phys >> 4;
ts.edx = dos_buf_phys & 15;
ts.v86_es = dos_buf_phys >> 4;
ts.edi = (dos_buf_phys & 15) + DOS_BUF_SIZE/2;
base_real_int(&ts);
/* If that failed, delete newpath and then retry the rename.
We _hope_ the failure was because newpath already existed;
the DOS error codes I'm getting back seem to be bogus. */
if ((err = dos_check_err(&ts)) != 0)
{
ts.trapno = 0x21;
ts.eax = 0x4100;
ts.v86_ds = dos_buf_phys >> 4;
ts.edx = (dos_buf_phys & 15) + DOS_BUF_SIZE/2;
base_real_int(&ts);
if ((err = dos_check_err(&ts)) != 0)
return err;
ts.trapno = 0x21;
ts.eax = 0x5600;
ts.v86_ds = dos_buf_phys >> 4;
ts.edx = dos_buf_phys & 15;
ts.v86_es = dos_buf_phys >> 4;
ts.edi = (dos_buf_phys & 15) + DOS_BUF_SIZE/2;
base_real_int(&ts);
err = dos_check_err(&ts);
}
int dos_read(dos_fd_t fd, void *buf, oskit_size_t size, oskit_size_t *out_actual)
{
int err;
int actual = 0;
struct trap_state ts;
oskit_addr_t dos_buf_phys = (oskit_addr_t)kvtophys(dos_buf);
assert(dos_buf); assert(dos_buf_phys);
assert(dos_buf_phys < 0x100000);
init_ts(&ts);
while (size > 0)
{
int little_size = size;
int little_actual;
if (little_size > DOS_BUF_SIZE)
little_size = DOS_BUF_SIZE;
ts.trapno = 0x21;
ts.eax = 0x3f00;
ts.ebx = fd;
ts.ecx = little_size;
ts.v86_ds = dos_buf_phys >> 4;
ts.edx = dos_buf_phys & 15;
base_real_int(&ts);
if ((err = dos_check_err(&ts)) != 0)
return err;
little_actual = ts.eax & 0xffff;
assert(little_actual <= little_size);
/* XXX don't copy if buf is <1MB */
memcpy(buf, dos_buf, little_actual);
buf += little_actual;
size -= little_actual;
actual += little_actual;
if (little_actual < little_size)
break;
}
*out_actual = actual;
return 0;
}
int dos_read(dos_fd_t fd, void *buf, vm_size_t size, vm_size_t *out_actual)
{
int err;
int actual = 0;
struct real_call_data real_call_data;
vm_offset_t dos_buf_phys = (vm_offset_t)kvtophys(dos_buf);
assert(dos_buf); assert(dos_buf_phys);
assert(dos_buf_phys < 0x100000);
dos_init_rcd(&real_call_data);
while (size > 0)
{
int little_size = size;
int little_actual;
if (little_size > DOS_BUF_SIZE)
little_size = DOS_BUF_SIZE;
real_call_data.eax = 0x3f00;
real_call_data.ebx = fd;
real_call_data.ecx = little_size;
real_call_data.ds = dos_buf_phys >> 4;
real_call_data.edx = dos_buf_phys & 15;
real_int(0x21, &real_call_data);
if (err = dos_check_err(&real_call_data))
return err;
little_actual = real_call_data.eax & 0xffff;
assert(little_actual <= little_size);
/* XXX don't copy if buf is <1MB */
memcpy(buf, dos_buf, little_actual);
buf += little_actual;
size -= little_actual;
actual += little_actual;
if (little_actual < little_size)
break;
}
*out_actual = actual;
return 0;
}