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| author | Pierre-Alexandre Meyer <pierre@mouraf.org> | 2009-04-19 21:06:39 -0700 |
|---|---|---|
| committer | Pierre-Alexandre Meyer <pierre@mouraf.org> | 2009-04-19 21:06:39 -0700 |
| commit | 8f67b34b0b99fbae6264dc0a34331d557e674b86 (patch) | |
| tree | 5c8edca5968b463f0549f8fec327a526657ba876 /com32/gpllib | |
| parent | d48c9f289d527656480199e844103a9907ebc4c5 (diff) | |
| download | syslinux-8f67b34b0b99fbae6264dc0a34331d557e674b86.tar.gz | |
gpllib: Add read_mbr helper (disk)
Impact: disk API extension
read_mbr takes a drive number and returns a pointer to a malloced buffer
containing its mbr.
Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
Diffstat (limited to 'com32/gpllib')
| -rw-r--r-- | com32/gpllib/disk/read.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/com32/gpllib/disk/read.c b/com32/gpllib/disk/read.c index 0e0be8ec..1db60fdd 100644 --- a/com32/gpllib/disk/read.c +++ b/com32/gpllib/disk/read.c @@ -6,6 +6,17 @@ #include <disk/read.h> /** + **/ +void *read_mbr(int drive) +{ + struct driveinfo drive_info; + drive_info.disk = drive; + + /* MBR: lba = 0, 1 sector */ + return read_sectors(&drive_info, 0, 1); +} + +/** * dev_read - read from a drive * @drive: Drive number * @lba: Position to start reading from @@ -37,7 +48,7 @@ void *read_sectors(struct driveinfo* drive_info, const unsigned int lba, void *buf = (char *)__com32.cs_bounce + sectors * SECTOR; void *data; - if (get_drive_parameters(drive_info)) + if (get_drive_parameters(drive_info) == -1) return NULL; memset(&inreg, 0, sizeof inreg); @@ -59,14 +70,14 @@ void *read_sectors(struct driveinfo* drive_info, const unsigned int lba, if (!drive_info->cbios) { /* We failed to get the geometry */ if (lba) - return NULL; /* Can only read MBR */ + return NULL; /* Can only read MBR */ s = 1; h = 0; c = 0; } else lba_to_chs(drive_info, lba, &s, &h, &c); if ( s > 63 || h > 256 || c > 1023 ) - return NULL; + return NULL; inreg.eax.w[0] = 0x0201; /* Read one sector */ inreg.ecx.b[1] = c & 0xff; |