Added remaining bus functions.
This commit is contained in:
Michael Brown
parent
7af89ccf33
commit
e3bb65c17f
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@ -1,18 +1,25 @@
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#include "realmode.h"
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#include "isa_ids.h"
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#include "bios_disks.h"
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#define CF ( 1 << 0 )
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#define BIOS_DISK_NONE 0
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struct disk_sector {
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char data[512];
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};
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/*
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* Ensure that there is sufficient space in the shared dev_bus
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* structure for a struct bios_disk_device.
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*
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*/
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DEV_BUS( struct bios_disk_device, bios_disk_dev );
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static char bios_disk_magic[0]; /* guaranteed unique symbol */
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/*
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* Reset the disk system using INT 13,0. Forces both hard disks and
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* floppy disks to seek back to track 0.
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*
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*/
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static void disk_init ( void ) {
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REAL_EXEC ( rm_disk_init,
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void bios_disk_init ( void ) {
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REAL_EXEC ( rm_bios_disk_init,
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"sti\n\t"
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"xorw %%ax,%%ax\n\t"
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"movb $0x80,%%dl\n\t"
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@ -28,16 +35,19 @@ static void disk_init ( void ) {
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/*
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* Read a single sector from a disk using INT 13,2.
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*
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* Returns the BIOS status code (%ah) - 0 indicates success
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* Returns the BIOS status code (%ah) - 0 indicates success.
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*
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*/
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static unsigned int pcbios_disk_read ( int drive, int cylinder, int head,
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int sector, struct disk_sector *buf ) {
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unsigned int bios_disk_read_once ( struct bios_disk_device *bios_disk,
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unsigned int cylinder,
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unsigned int head,
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unsigned int sector,
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struct bios_disk_sector *buf ) {
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uint16_t basemem_buf, status, flags;
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int discard_c, discard_d;
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basemem_buf = BASEMEM_PARAMETER_INIT ( *buf );
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REAL_EXEC ( rm_pcbios_disk_read,
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REAL_EXEC ( rm_bios_disk_read,
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"sti\n\t"
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"movw $0x0201, %%ax\n\t" /* Read a single sector */
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"int $0x13\n\t"
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@ -46,14 +56,113 @@ static unsigned int pcbios_disk_read ( int drive, int cylinder, int head,
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"cli\n\t",
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4,
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OUT_CONSTRAINTS ( "=a" ( status ), "=b" ( flags ),
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"=c" ( discard_c ), "=d" ( discard_d ) ),
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"=c" ( discard_c ),
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"=d" ( discard_d ) ),
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IN_CONSTRAINTS ( "c" ( ( ( cylinder & 0xff ) << 8 ) |
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( ( cylinder >> 8 ) & 0x3 ) |
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sector ),
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"d" ( ( head << 8 ) | drive ),
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"d" ( ( head << 8 ) | bios_disk->drive ),
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"b" ( basemem_buf ) ),
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CLOBBER ( "ebp", "esi", "edi" ) );
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BASEMEM_PARAMETER_DONE ( *buf );
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return ( flags & CF ) ? ( status >> 8 ) : 0;
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return ( flags & CF ) ? ( status >> 8 ) : 0;
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}
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/*
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* Fill in parameters for a BIOS disk device based on drive number
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*
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*/
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static int fill_bios_disk_device ( struct bios_disk_device *bios_disk ) {
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uint16_t type, flags;
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REAL_EXEC ( rm_bios_disk_exists,
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"sti\n\t"
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"movb $0x15, %%ah\n\t"
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"int $0x13\n\t"
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"pushfw\n\t"
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"popw %%dx\n\t"
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"cli\n\t",
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2,
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OUT_CONSTRAINTS ( "=a" ( type ), "=d" ( flags ) ),
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IN_CONSTRAINTS ( "d" ( bios_disk->drive ) ),
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CLOBBER ( "ebx", "ecx", "esi", "edi", "ebp" ) );
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if ( ( flags & CF ) ||
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( ( type >> 8 ) == BIOS_DISK_NONE ) )
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return 0;
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DBG ( "BIOS disk found valid drive %hhx\n", bios_disk->drive );
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return 1;
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}
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/*
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* Find a BIOS disk device matching the specified driver
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*
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*/
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int find_bios_disk_device ( struct bios_disk_device *bios_disk,
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struct bios_disk_driver *driver ) {
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/* Initialise struct bios_disk if it's the first time it's been used.
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*/
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if ( bios_disk->magic != bios_disk_magic ) {
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memset ( bios_disk, 0, sizeof ( *bios_disk ) );
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bios_disk->magic = bios_disk_magic;
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}
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/* Iterate through all possible BIOS drives, starting where we
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* left off
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*/
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DBG ( "BIOS disk searching for device matching driver %s\n",
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driver->name );
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do {
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/* If we've already used this device, skip it */
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if ( bios_disk->already_tried ) {
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bios_disk->already_tried = 0;
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continue;
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}
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/* Fill in device parameters */
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if ( ! fill_bios_disk_device ( bios_disk ) ) {
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continue;
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}
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/* Compare against driver's valid ID range */
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if ( ( bios_disk->drive >= driver->min_drive ) &&
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( bios_disk->drive <= driver->max_drive ) ) {
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driver->fill_drive_name ( bios_disk->drive,
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bios_disk->name );
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DBG ( "BIOS_DISK found drive %hhx (\"%s\") "
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"matching driver %s\n",
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bios_disk->drive, bios_disk->name,
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driver->name );
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bios_disk->already_tried = 1;
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return 1;
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}
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} while ( ++bios_disk->drive );
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/* No device found */
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DBG ( "BIOS disk found no device matching driver %s\n", driver->name );
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return 0;
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}
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/*
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* Find the next MCA device that can be used to boot using the
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* specified driver.
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*
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*/
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int find_bios_disk_boot_device ( struct dev *dev,
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struct bios_disk_driver *driver ) {
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struct bios_disk_device *bios_disk
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= ( struct bios_disk_device * ) dev->bus;
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if ( ! find_bios_disk_device ( bios_disk, driver ) )
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return 0;
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dev->name = bios_disk->name;
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dev->devid.bus_type = ISA_BUS_TYPE;
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dev->devid.vendor_id = ISA_VENDOR ( 'D', 'S', 'K' );
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dev->devid.device_id = bios_disk->drive;
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return 1;
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}
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