diff options
Diffstat (limited to 'os/boot/pc/sdbios.c')
| -rw-r--r-- | os/boot/pc/sdbios.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/os/boot/pc/sdbios.c b/os/boot/pc/sdbios.c new file mode 100644 index 00000000..fd4fe681 --- /dev/null +++ b/os/boot/pc/sdbios.c @@ -0,0 +1,165 @@ +/* + * boot driver for BIOS devices with partitions + * devbios must be called first + */ +#include "u.h" +#include "lib.h" +#include "mem.h" +#include "dat.h" +#include "fns.h" +#include "io.h" +#include "ureg.h" +#include "error.h" + +#include "sd.h" +#include "fs.h" + +long biosread(Fs *, void *, long); +vlong biosseek(Fs *fs, vlong off); + +extern SDifc sdbiosifc; +extern int onlybios0, biosinited; + +int +biosverify(SDunit* ) +{ + if (onlybios0 || !biosinited) + return 0; + return 1; +} + +int +biosonline(SDunit* unit) +{ + if (onlybios0 || !biosinited || !unit) + return 0; + unit->sectors = 1UL << 30; /* a bunch */ + unit->secsize = 512; /* conventional */ + return 1; +} + +static int +biosrio(SDreq* r) +{ + int nb; + long got; + vlong len, off; + uchar *p; + Fs fs; /* just for fs->dev, which is zero */ + + if (onlybios0 || !biosinited) + return SDeio; + /* + * Most SCSI commands can be passed unchanged except for + * the padding on the end. The few which require munging + * are not used internally. Mode select/sense(6) could be + * converted to the 10-byte form but it's not worth the + * effort. Read/write(6) are easy. + */ + r->rlen = 0; + r->status = SDok; + switch(r->cmd[0]){ + case 0x08: /* read */ + case 0x28: /* read */ + if (r->cmd[0] == 0x08) + panic("biosrio: 0x08 read op\n"); + off = r->cmd[2]<<24 | r->cmd[3]<<16 | r->cmd[4]<<8 | r->cmd[5]; + nb = r->cmd[7]<<8 | r->cmd[8]; /* often 4 */ + USED(nb); /* is nb*512 == r->dlen? */ + memset(&fs, 0, sizeof fs); + biosseek(&fs, off*512); + got = biosread(&fs, r->data, r->dlen); + if (got < 0) + r->status = SDeio; + else + r->rlen = got; + break; + case 0x0A: /* write */ + case 0x2A: /* write */ + r->status = SDeio; /* boot programs don't write */ + break; + case 0x25: /* read capacity */ + /* + * Read capacity returns the LBA of the last sector. + */ + len = r->unit->sectors - 1; + p = r->data; + *p++ = len>>24; + *p++ = len>>16; + *p++ = len>>8; + *p++ = len; + len = r->unit->secsize; + *p++ = len>>24; + *p++ = len>>16; + *p++ = len>>8; + *p = len; + r->data = (char *)r->data + 8; + return SDok; + case 0x9E: /* long read capacity */ + /* + * Read capacity returns the LBA of the last sector. + */ + len = r->unit->sectors - 1; + p = r->data; + *p++ = len>>56; + *p++ = len>>48; + *p++ = len>>40; + *p++ = len>>32; + *p++ = len>>24; + *p++ = len>>16; + *p++ = len>>8; + *p++ = len; + len = r->unit->secsize; + *p++ = len>>24; + *p++ = len>>16; + *p++ = len>>8; + *p = len; + r->data = (char *)r->data + 8; + return SDok; + /* ignore others */ + } + return r->status; +} + +SDev* +biosid(SDev* sdev) +{ + for (; sdev; sdev = sdev->next) + if (sdev->ifc == &sdbiosifc) + sdev->idno = 'B'; + return sdev; +} + +static SDev* +biospnp(void) +{ + SDev *sdev; + + /* 9pxeload can't use bios int 13 calls; they wedge the machine */ + if (pxe || getconf("*nobiosload") != nil || onlybios0 || !biosinited) + return nil; + if((sdev = malloc(sizeof(SDev))) != nil) { + sdev->ifc = &sdbiosifc; + sdev->index = -1; + sdev->nunit = 1; + } + return sdev; +} + +SDifc sdbiosifc = { + "bios", /* name */ + + biospnp, /* pnp */ + nil, /* legacy */ + biosid, /* id */ + nil, /* enable */ + nil, /* disable */ + + biosverify, /* verify */ + biosonline, /* online */ + biosrio, /* rio */ + nil, /* rctl */ + nil, /* wctl */ + + scsibio, /* bio */ +}; |