diff options
| -rw-r--r-- | hw/ide/ahci.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index 744d19d6db..1f008a3dda 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -884,8 +884,31 @@ static int handle_cmd(AHCIState *s, int port, int slot) } if (ide_state->drive_kind != IDE_CD) { - ide_set_sector(ide_state, (cmd_fis[6] << 16) | (cmd_fis[5] << 8) | - cmd_fis[4]); + /* + * We set the sector depending on the sector defined in the FIS. + * Unfortunately, the spec isn't exactly obvious on this one. + * + * Apparently LBA48 commands set fis bytes 10,9,8,6,5,4 to the + * 48 bit sector number. ATA_CMD_READ_DMA_EXT is an example for + * such a command. + * + * Non-LBA48 commands however use 7[lower 4 bits],6,5,4 to define a + * 28-bit sector number. ATA_CMD_READ_DMA is an example for such + * a command. + * + * Since the spec doesn't explicitly state what each field should + * do, I simply assume non-used fields as reserved and OR everything + * together, independent of the command. + */ + ide_set_sector(ide_state, ((uint64_t)cmd_fis[10] << 40) + | ((uint64_t)cmd_fis[9] << 32) + /* This is used for LBA48 commands */ + | ((uint64_t)cmd_fis[8] << 24) + /* This is used for non-LBA48 commands */ + | ((uint64_t)(cmd_fis[7] & 0xf) << 24) + | ((uint64_t)cmd_fis[6] << 16) + | ((uint64_t)cmd_fis[5] << 8) + | cmd_fis[4]); } /* Copy the ACMD field (ATAPI packet, if any) from the AHCI command |