diff options
Diffstat (limited to 'com32/gpllib/disk/read.c')
| -rw-r--r-- | com32/gpllib/disk/read.c | 130 |
1 files changed, 66 insertions, 64 deletions
diff --git a/com32/gpllib/disk/read.c b/com32/gpllib/disk/read.c index 74840829..7a6cc430 100644 --- a/com32/gpllib/disk/read.c +++ b/com32/gpllib/disk/read.c @@ -36,11 +36,11 @@ **/ int read_mbr(int drive, void *buf) { - struct driveinfo drive_info; - drive_info.disk = drive; + struct driveinfo drive_info; + drive_info.disk = drive; - /* MBR: lba = 0, 1 sector */ - return read_sectors(&drive_info, buf, 0, 1); + /* MBR: lba = 0, 1 sector */ + return read_sectors(&drive_info, buf, 0, 1); } /** @@ -54,12 +54,12 @@ int read_mbr(int drive, void *buf) * Return the number of sectors read on success or -1 on failure. * errno_disk contains the error number. **/ -int dev_read(int drive, void * buf, unsigned int lba, int sectors) +int dev_read(int drive, void *buf, unsigned int lba, int sectors) { - struct driveinfo drive_info; - drive_info.disk = drive; + struct driveinfo drive_info; + drive_info.disk = drive; - return read_sectors(&drive_info, buf, lba, sectors); + return read_sectors(&drive_info, buf, lba, sectors); } /** @@ -72,62 +72,64 @@ int dev_read(int drive, void * buf, unsigned int lba, int sectors) * Return the number of sectors read on success or -1 on failure. * errno_disk contains the error number. **/ -int read_sectors(struct driveinfo* drive_info, void *data, +int read_sectors(struct driveinfo *drive_info, void *data, const unsigned int lba, const int sectors) { - com32sys_t inreg, outreg; - struct ebios_dapa *dapa = __com32.cs_bounce; - void *buf = (char *)__com32.cs_bounce + sectors * SECTOR; - char *bufp = data; - - if (get_drive_parameters(drive_info) == -1) - return -1; - - memset(&inreg, 0, sizeof inreg); - - if (drive_info->ebios) { - dapa->len = sizeof(*dapa); - dapa->count = sectors; - dapa->off = OFFS(buf); - dapa->seg = SEG(buf); - dapa->lba = lba; - - inreg.esi.w[0] = OFFS(dapa); - inreg.ds = SEG(dapa); - inreg.edx.b[0] = drive_info->disk; - inreg.eax.b[1] = 0x42; /* Extended read */ - } else { - unsigned int c, h, s; - - if (!drive_info->cbios) { // XXX errno - /* We failed to get the geometry */ - if (lba) - return -1; /* Can only read MBR */ - - s = 1; h = 0; c = 0; - } else - lba_to_chs(drive_info, lba, &s, &h, &c); - - // XXX errno - if ( s > 63 || h > 256 || c > 1023 ) - return -1; - - inreg.eax.w[0] = 0x0201; /* Read one sector */ - inreg.ecx.b[1] = c & 0xff; - inreg.ecx.b[0] = s + (c >> 6); - inreg.edx.b[1] = h; - inreg.edx.b[0] = drive_info->disk; - inreg.ebx.w[0] = OFFS(buf); - inreg.es = SEG(buf); - } - - /* Perform the read */ - if (int13_retry(&inreg, &outreg)) { - errno_disk = outreg.eax.b[1]; - return -1; /* Give up */ - } - - memcpy(bufp, buf, sectors * SECTOR); - - return sectors; + com32sys_t inreg, outreg; + struct ebios_dapa *dapa = __com32.cs_bounce; + void *buf = (char *)__com32.cs_bounce + sectors * SECTOR; + char *bufp = data; + + if (get_drive_parameters(drive_info) == -1) + return -1; + + memset(&inreg, 0, sizeof inreg); + + if (drive_info->ebios) { + dapa->len = sizeof(*dapa); + dapa->count = sectors; + dapa->off = OFFS(buf); + dapa->seg = SEG(buf); + dapa->lba = lba; + + inreg.esi.w[0] = OFFS(dapa); + inreg.ds = SEG(dapa); + inreg.edx.b[0] = drive_info->disk; + inreg.eax.b[1] = 0x42; /* Extended read */ + } else { + unsigned int c, h, s; + + if (!drive_info->cbios) { // XXX errno + /* We failed to get the geometry */ + if (lba) + return -1; /* Can only read MBR */ + + s = 1; + h = 0; + c = 0; + } else + lba_to_chs(drive_info, lba, &s, &h, &c); + + // XXX errno + if (s > 63 || h > 256 || c > 1023) + return -1; + + inreg.eax.w[0] = 0x0201; /* Read one sector */ + inreg.ecx.b[1] = c & 0xff; + inreg.ecx.b[0] = s + (c >> 6); + inreg.edx.b[1] = h; + inreg.edx.b[0] = drive_info->disk; + inreg.ebx.w[0] = OFFS(buf); + inreg.es = SEG(buf); + } + + /* Perform the read */ + if (int13_retry(&inreg, &outreg)) { + errno_disk = outreg.eax.b[1]; + return -1; /* Give up */ + } + + memcpy(bufp, buf, sectors * SECTOR); + + return sectors; } |