/* * boot driver for BIOS devices with partitions. * devbios must be initialised 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; uchar *putbeul(ulong ul, uchar *p){	*p++ = ul >> 24;	*p++ = ul >> 16;	*p++ = ul >> 8;	*p++ = ul;	return p;} uchar *putbeuvl(uvlong uvl, uchar *p){	*p++ = uvl >> 56;	*p++ = uvl >> 48;	*p++ = uvl >> 40;	*p++ = uvl >> 32;	*p++ = uvl >> 24;	*p++ = uvl >> 16;	*p++ = uvl >> 8;	*p++ = uvl;	return p;} intbiosverify(SDunit* ){	if (onlybios0 || !biosinited)		return 0;	return 1;} intbiosonline(SDunit* unit){	if (onlybios0 || !biosinited || !unit)		return 0;	unit->secsize = 512;			/* conventional */	unit->sectors = ~0ULL / unit->secsize;	/* all of them, and then some */	return 1;} static intbiosrio(SDreq* r){	int nb;	long got;	vlong 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");		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; 		/*		 * Read capacity returns the LBA of the last sector.		 */	case 0x25:			/* read capacity */		p = putbeul(r->unit->sectors - 1, r->data);		r->data = putbeul(r->unit->secsize, p);		return SDok;	case 0x9E:			/* long read capacity */		p = putbeuvl(r->unit->sectors - 1, r->data);		r->data = putbeul(r->unit->secsize, p);		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 || !biosload || 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 */};