diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2009-11-11 16:05:34 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-11-11 16:05:34 -0800 |
| commit | e5a014f403aabb9400f309a0bef08288d6421107 (patch) | |
| tree | 29d136a9460b22fe9fc4f1e6cf8c076ac4a9f934 /dos | |
| parent | e79ba125c9c8eb3816d164d86b5264b21868f7af (diff) | |
| download | syslinux-e5a014f403aabb9400f309a0bef08288d6421107.tar.gz | |
dos: always try the FAT32-aware direct I/O calls first
Always try the FAT32-aware direct I/O calls before trying the legacy
raw I/O calls. The reason for doing this is that the FAT32 stuff may
be implemented as an add-on.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'dos')
| -rw-r--r-- | dos/syslinux.c | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/dos/syslinux.c b/dos/syslinux.c index d054c4ce..ca2fd8e1 100644 --- a/dos/syslinux.c +++ b/dos/syslinux.c @@ -171,13 +171,15 @@ void write_device(int drive, const void *buf, size_t nsecs, unsigned int sector) dio.bufoffs = (uintptr_t) buf; dio.bufseg = data_segment(); - if (dos_version >= 0x070a) { - asm volatile("int $0x21 ; setc %0" - : "=bcdm" (err), "=a" (errnum) - : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive), - "S" (1), "m" (dio) - : "memory"); - } else { + /* Try FAT32-aware system call first */ + asm volatile("int $0x21 ; setc %0" + : "=bcdm" (err), "=a" (errnum) + : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive), + "S" (1), "m" (dio) + : "memory"); + + if (err && errnum == 0x0001) { + /* Try legacy system call */ asm volatile("int $0x26 ; setc %0 ; popfw" : "=bcdm" (err), "=a" (errnum) : "a" (drive-1), "b" (&dio), "c" (-1), "d" (buf), @@ -204,12 +206,14 @@ void read_device(int drive, const void *buf, size_t nsecs, unsigned int sector) dio.bufoffs = (uintptr_t) buf; dio.bufseg = data_segment(); - if (dos_version >= 0x070a) { - asm volatile("int $0x21 ; setc %0" - : "=bcdm" (err), "=a" (errnum) - : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive), - "S" (0), "m" (dio)); - } else { + /* Try FAT32-aware system call first */ + asm volatile("int $0x21 ; setc %0" + : "=bcdm" (err), "=a" (errnum) + : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive), + "S" (0), "m" (dio)); + + if (err && errnum == 0x0001) { + /* Try legacy system call */ asm volatile("int $0x25 ; setc %0 ; popfw" : "=bcdm" (err), "=a" (errnum) : "a" (drive-1), "b" (&dio), "c" (-1), "d" (buf), |