From 7af89ccf33ccbe862aae094d2aeac3c8c42080ab Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Mon, 18 Apr 2005 15:48:20 +0000 Subject: [PATCH] Code fixed to operate correctly. --- src/arch/i386/drivers/bus/bios_disks.c | 49 ++++++++++++++------------ 1 file changed, 26 insertions(+), 23 deletions(-) diff --git a/src/arch/i386/drivers/bus/bios_disks.c b/src/arch/i386/drivers/bus/bios_disks.c index d765111d..dfb8626d 100644 --- a/src/arch/i386/drivers/bus/bios_disks.c +++ b/src/arch/i386/drivers/bus/bios_disks.c @@ -2,10 +2,16 @@ #define CF ( 1 << 0 ) -/************************************************************************** -DISK_INIT - Initialize the disk system -**************************************************************************/ -void disk_init ( void ) { +struct disk_sector { + char data[512]; +}; + +/* + * Reset the disk system using INT 13,0. Forces both hard disks and + * floppy disks to seek back to track 0. + * + */ +static void disk_init ( void ) { REAL_EXEC ( rm_disk_init, "sti\n\t" "xorw %%ax,%%ax\n\t" @@ -19,38 +25,35 @@ void disk_init ( void ) { "ebp", "esi", "edi" ) ); } -/************************************************************************** -DISK_READ - Read a sector from disk -**************************************************************************/ -unsigned int pcbios_disk_read ( int drive, int cylinder, int head, int sector, - char *fixme_buf ) { - uint16_t ax, flags, discard_c, discard_d; - segoff_t buf = SEGOFF ( fixme_buf ); - - /* FIXME: buf should be passed in as a segoff_t rather than a - * char * - */ +/* + * Read a single sector from a disk using INT 13,2. + * + * Returns the BIOS status code (%ah) - 0 indicates success + * + */ +static unsigned int pcbios_disk_read ( int drive, int cylinder, int head, + int sector, struct disk_sector *buf ) { + uint16_t basemem_buf, status, flags; + int discard_c, discard_d; + basemem_buf = BASEMEM_PARAMETER_INIT ( *buf ); REAL_EXEC ( rm_pcbios_disk_read, "sti\n\t" - "pushl %%ebx\n\t" /* Convert %ebx to %es:bx */ - "popw %%bx\n\t" - "popw %%es\n\t" - "movb $0x02, %%ah\n\t" /* INT 13,2 - Read disk sector */ - "movb $0x01, %%al\n\t" /* Read one sector */ + "movw $0x0201, %%ax\n\t" /* Read a single sector */ "int $0x13\n\t" "pushfw\n\t" "popw %%bx\n\t" "cli\n\t", 4, - OUT_CONSTRAINTS ( "=a" ( ax ), "=b" ( flags ), + OUT_CONSTRAINTS ( "=a" ( status ), "=b" ( flags ), "=c" ( discard_c ), "=d" ( discard_d ) ), IN_CONSTRAINTS ( "c" ( ( ( cylinder & 0xff ) << 8 ) | ( ( cylinder >> 8 ) & 0x3 ) | sector ), "d" ( ( head << 8 ) | drive ), - "b" ( buf ) ), + "b" ( basemem_buf ) ), CLOBBER ( "ebp", "esi", "edi" ) ); + BASEMEM_PARAMETER_DONE ( *buf ); - return ( flags & CF ) ? ax : 0; + return ( flags & CF ) ? ( status >> 8 ) : 0; }