text: /* This file contains the "device dependent" part of a hard disk driver that
   * uses the ROM BIOS.  It makes a call and just waits for the transfer to
   * happen.  It is not interrupt driven and thus will (*) have poor performance.
   * The advantage is that it should work on virtually any PC, XT, 386, PS/2
   * or clone.  The demo disk uses this driver.  It is suggested that all
   * MINIX users try the other drivers, and use this one only as a last resort,
   * if all else fails.
   *
   * (*) The performance is within 10% of the AT driver for reads on any disk
   *     and writes on a 2:1 interleaved disk, it will be DMA_BUF_SIZE bytes
   *     per revolution for a minimum of 60 kb/s for writes to 1:1 disks.
   *
   * The file contains one entry point:
   *
   *	 bios_winchester_task:	main entry when system is brought up
   *
   *
   * Changes:
   *	30 Apr 1992 by Kees J. Bot: device dependent/independent split.
   *	14 May 2000 by Kees J. Bot: d-d/i rewrite.
   */
  
  #include "../drivers.h"
  #include "../libdriver/driver.h"
  #include "../libdriver/drvlib.h"
  #include <minix/sysutil.h>
  #include <minix/keymap.h>
  #include <sys/ioc_disk.h>
  #include <ibm/int86.h>
  #include <assert.h>
  
  #define ME "BIOS_WINI"
  
  /* Error codes */
  #define ERR		 (-1)	/* general error */
  
  /* Parameters for the disk drive. */
  #define MAX_DRIVES         8	/* this driver supports 8 drives (d0 - d7)*/
  #define MAX_SECS	 255	/* bios can transfer this many sectors */
  #define NR_MINORS      (MAX_DRIVES * DEV_PER_DRIVE)
  #define SUB_PER_DRIVE	(NR_PARTITIONS * NR_PARTITIONS)
  #define NR_SUBDEVS	(MAX_DRIVES * SUB_PER_DRIVE)
  
  PRIVATE int pc_at = 1;	/* What about PC XTs? */
  
  /* Variables. */
  PRIVATE struct wini {		/* main drive struct, one entry per drive */
    unsigned cylinders;		/* number of cylinders */
    unsigned heads;		/* number of heads */
    unsigned sectors;		/* number of sectors per track */
    unsigned open_ct;		/* in-use count */
    int drive_id;			/* Drive ID at BIOS level */
    int present;			/* Valid drive */
    int int13ext;			/* IBM/MS INT 13 extensions supported? */
    struct device part[DEV_PER_DRIVE];	/* disks and partitions */
    struct device subpart[SUB_PER_DRIVE]; /* subpartitions */
  } wini[MAX_DRIVES], *w_wn;
  
  PRIVATE int w_drive;			/* selected drive */
  PRIVATE struct device *w_dv;		/* device's base and size */
  PRIVATE vir_bytes bios_buf_vir, bios_buf_size;
  PRIVATE phys_bytes bios_buf_phys;
  PRIVATE int remap_first = 0;		/* Remap drives for CD HD emulation */
  
  _PROTOTYPE(int main, (void) );
  FORWARD _PROTOTYPE( struct device *w_prepare, (int device) );
  FORWARD _PROTOTYPE( char *w_name, (void) );
  FORWARD _PROTOTYPE( int w_transfer, (int proc_nr, int opcode, off_t position,
  					iovec_t *iov, unsigned nr_req) );
  FORWARD _PROTOTYPE( int w_do_open, (struct driver *dp, message *m_ptr) );
  FORWARD _PROTOTYPE( int w_do_close, (struct driver *dp, message *m_ptr) );
  FORWARD _PROTOTYPE( void w_init, (void) );
  FORWARD _PROTOTYPE( void w_geometry, (struct partition *entry));
  FORWARD _PROTOTYPE( int w_other, (struct driver *dp, message *m_ptr)    );
  
  /* Entry points to this driver. */
  PRIVATE struct driver w_dtab = {
    w_name,	/* current device's name */
    w_do_open,	/* open or mount request, initialize device */
    w_do_close,	/* release device */
    do_diocntl,	/* get or set a partition's geometry */
    w_prepare,	/* prepare for I/O on a given minor device */
    w_transfer,	/* do the I/O */
    nop_cleanup,	/* no cleanup needed */
    w_geometry,	/* tell the geometry of the disk */
    nop_signal,		/* no cleanup needed on shutdown */
    nop_alarm,		/* ignore leftover alarms */
    nop_cancel,		/* ignore CANCELs */
    nop_select,		/* ignore selects */
    w_other,		/* catch-all for unrecognized commands and ioctls */
    NULL			/* leftover hardware interrupts */
  };
  
  /*===========================================================================*
   *				bios_winchester_task			     *
   *===========================================================================*/
  PUBLIC int main()
  {
    long v;
  
    v= 0;
    env_parse("bios_remap_first", "d", 0, &v, 0, 1);
    remap_first= v;
  
  /* Set special disk parameters then call the generic main loop. */
    driver_task(&w_dtab);
    return(OK);
  }
  
  /*===========================================================================*
   *				w_prepare				     *
   *===========================================================================*/
  PRIVATE struct device *w_prepare(device)
  int device;
  {
  /* Prepare for I/O on a device. */
  
    if (device < NR_MINORS) {			/* d0, d0p[0-3], d1, ... */
  	w_drive = device / DEV_PER_DRIVE;	/* save drive number */
  	w_wn = &wini[w_drive];
  	w_dv = &w_wn->part[device % DEV_PER_DRIVE];
    } else
    if ((unsigned) (device -= MINOR_d0p0s0) < NR_SUBDEVS) {/*d[0-7]p[0-3]s[0-3]*/
  	w_drive = device / SUB_PER_DRIVE;
  	w_wn = &wini[w_drive];
  	w_dv = &w_wn->subpart[device % SUB_PER_DRIVE];
    } else {
  	return(NIL_DEV);
    }
    if (w_drive >= MAX_DRIVES || !w_wn->present)
    	return NIL_DEV;
    return(w_dv);
  }
  
  /*===========================================================================*
   *				w_name					     *
   *===========================================================================*/
  PRIVATE char *w_name()
  {
  /* Return a name for the current device. */
    static char name[] = "bios-d0";
  
    name[6] = '0' + w_drive;
    return name;
  }
  
  /*===========================================================================*
   *				w_transfer				     *
   *===========================================================================*/
  PRIVATE int w_transfer(proc_nr, opcode, position, iov, nr_req)
  int proc_nr;			/* process doing the request */
  int opcode;			/* DEV_GATHER or DEV_SCATTER */
  off_t position;			/* offset on device to read or write */
  iovec_t *iov;			/* pointer to read or write request vector */
  unsigned nr_req;		/* length of request vector */
  {
    struct wini *wn = w_wn;
    iovec_t *iop, *iov_end = iov + nr_req;
    int r, errors;
    unsigned nbytes, count, chunk;
    unsigned long block;
    vir_bytes i13e_rw_off, rem_buf_size;
    unsigned long dv_size = cv64ul(w_dv->dv_size);
    unsigned secspcyl = wn->heads * wn->sectors;
    struct int13ext_rw {
  	u8_t	len;
  	u8_t	res1;
  	u16_t	count;
  	u16_t	addr[2];
  	u32_t	block[2];
    } i13e_rw;
    struct reg86u reg86;
  
    /* Check disk address. */
    if ((position & SECTOR_MASK) != 0) return(EINVAL);
  
    errors = 0;
  
    i13e_rw_off= bios_buf_size-sizeof(i13e_rw);
    rem_buf_size= (i13e_rw_off & ~SECTOR_MASK);
    assert(rem_buf_size != 0);
  
    while (nr_req > 0) {
  	/* How many bytes to transfer? */
  	nbytes = 0;
  	for (iop = iov; iop < iov_end; iop++) {
  		if (nbytes + iop->iov_size > rem_buf_size) {
  			/* Don't do half a segment if you can avoid it. */
  			if (nbytes == 0) nbytes = rem_buf_size;
  			break;
  		}
  		nbytes += iop->iov_size;
  	}
  	if ((nbytes & SECTOR_MASK) != 0) return(EINVAL);
  
  	/* Which block on disk and how close to EOF? */
  	if (position >= dv_size) return(OK);		/* At EOF */
  	if (position + nbytes > dv_size) nbytes = dv_size - position;
  	block = div64u(add64ul(w_dv->dv_base, position), SECTOR_SIZE);
  
  	/* Degrade to per-sector mode if there were errors. */
  	if (errors > 0) nbytes = SECTOR_SIZE;
  
  	if (opcode == DEV_SCATTER) {
  		/* Copy from user space to the DMA buffer. */
  		count = 0;
  		for (iop = iov; count < nbytes; iop++) {
  			chunk = iov->iov_size;
  			if (count + chunk > nbytes) chunk = nbytes - count;
  			assert(chunk <= rem_buf_size);
  			r= sys_vircopy(proc_nr, D, iop->iov_addr,
  				SYSTEM, D, bios_buf_vir+count, 
  				chunk);
  			if (r != OK)
  				panic(ME, "sys_vircopy failed", r);
  			count += chunk;
  		}
  	}
  
  	/* Do the transfer */
  	if (wn->int13ext) {
  		i13e_rw.len = 0x10;
  		i13e_rw.res1 = 0;
  		i13e_rw.count = nbytes >> SECTOR_SHIFT;
  		i13e_rw.addr[0] = bios_buf_phys % HCLICK_SIZE;
  		i13e_rw.addr[1] = bios_buf_phys / HCLICK_SIZE;
  		i13e_rw.block[0] = block;
  		i13e_rw.block[1] = 0;
  		r= sys_vircopy(SELF, D, (vir_bytes)&i13e_rw,
  			SYSTEM, D, (bios_buf_vir+i13e_rw_off), 
  			sizeof(i13e_rw));
  		if (r != OK)
  			panic(ME, "sys_vircopy failed", r);
  
  		/* Set up an extended read or write BIOS call. */
  		reg86.u.b.intno = 0x13;
  		reg86.u.w.ax = opcode == DEV_SCATTER ? 0x4300 : 0x4200;
  		reg86.u.b.dl = wn->drive_id;
  		reg86.u.w.si = (bios_buf_phys + i13e_rw_off) % HCLICK_SIZE;
  		reg86.u.w.ds = (bios_buf_phys + i13e_rw_off) / HCLICK_SIZE;
  	} else {
  		/* Set up an ordinary read or write BIOS call. */
  		unsigned cylinder = block / secspcyl;
  		unsigned sector = (block % wn->sectors) + 1;
  		unsigned head = (block % secspcyl) / wn->sectors;
  
  		reg86.u.b.intno = 0x13;
  		reg86.u.b.ah = opcode == DEV_SCATTER ? 0x03 : 0x02;
  		reg86.u.b.al = nbytes >> SECTOR_SHIFT;
  		reg86.u.w.bx = bios_buf_phys % HCLICK_SIZE;
  		reg86.u.w.es = bios_buf_phys / HCLICK_SIZE;
  		reg86.u.b.ch = cylinder & 0xFF;
  		reg86.u.b.cl = sector | ((cylinder & 0x300) >> 2);
  		reg86.u.b.dh = head;
  		reg86.u.b.dl = wn->drive_id;
  	}
  
  	r= sys_int86(&reg86);
  	if (r != OK)
  		panic(ME, "BIOS call failed", r);
  
  	if (reg86.u.w.f & 0x0001) {
  		/* An error occurred, try again sector by sector unless */
  		if (++errors == 2) return(EIO);
  		continue;
  	}
  
  	if (opcode == DEV_GATHER) {
  		/* Copy from the DMA buffer to user space. */
  		count = 0;
  		for (iop = iov; count < nbytes; iop++) {
  			chunk = iov->iov_size;
  			if (count + chunk > nbytes) chunk = nbytes - count;
  			assert(chunk <= rem_buf_size);
  			r= sys_vircopy(SYSTEM, D, bios_buf_vir+count, 
  				proc_nr, D, iop->iov_addr,
  				chunk);
  			if (r != OK)
  				panic(ME, "sys_vircopy failed", r);
  			count += chunk;
  		}
  	}
  
  	/* Book the bytes successfully transferred. */
  	position += nbytes;
  	for (;;) {
  		if (nbytes < iov->iov_size) {
  			/* Not done with this one yet. */
  			iov->iov_addr += nbytes;
  			iov->iov_size -= nbytes;
  			break;
  		}
  		nbytes -= iov->iov_size;
  		iov->iov_addr += iov->iov_size;
  		iov->iov_size = 0;
  		if (nbytes == 0) {
  			/* The rest is optional, so we return to give FS a
  			 * chance to think it over.
  			 */
  			return(OK);
  		}
  		iov++;
  		nr_req--;
  	}
    }
    return(OK);
  }
  
  /*============================================================================*
   *				w_do_open				      *
   *============================================================================*/
  PRIVATE int w_do_open(dp, m_ptr)
  struct driver *dp;
  message *m_ptr;
  {
  /* Device open: Initialize the controller and read the partition table. */
  
    static int init_done = FALSE;
  
    if (!init_done) { w_init(); init_done = TRUE; }
  
    if (w_prepare(m_ptr->DEVICE) == NIL_DEV) return(ENXIO);
  
    if (w_wn->open_ct++ == 0) {
  	/* Partition the disk. */
  	partition(&w_dtab, w_drive * DEV_PER_DRIVE, P_PRIMARY, 0);
    }
    return(OK);
  }
  
  /*============================================================================*
   *				w_do_close				      *
   *============================================================================*/
  PRIVATE int w_do_close(dp, m_ptr)
  struct driver *dp;
  message *m_ptr;
  {
  /* Device close: Release a device. */
  
    if (w_prepare(m_ptr->DEVICE) == NIL_DEV) return(ENXIO);
    w_wn->open_ct--;
    return(OK);
  }
  
  /*===========================================================================*
   *				w_init					     *
   *===========================================================================*/
  PRIVATE void w_init()
  {
  /* This routine is called at startup to initialize the drive parameters. */
  
    int r, drive, drive_id, nr_drives;
    struct wini *wn;
    unsigned long capacity;
    struct int13ext_params {
  	u16_t	len;
  	u16_t	flags;
  	u32_t	cylinders;
  	u32_t	heads;
  	u32_t	sectors;
  	u32_t	capacity[2];
  	u16_t	bts_per_sec;
  	u16_t	config[2];
    } i13e_par;
    struct reg86u reg86;
  
    /* Ask the system task for a suitable buffer */
    r= sys_getbiosbuffer(&bios_buf_vir, &bios_buf_size);
    if (r != OK)
    	panic(ME, "sys_getbiosbuffer failed", r);
    r= sys_umap(SYSTEM, D, (vir_bytes)bios_buf_vir, (phys_bytes)bios_buf_size,
    	&bios_buf_phys);
    if (r != OK)
    	panic(ME, "sys_umap failed", r);
    if (bios_buf_phys+bios_buf_size > 0x100000)
    	panic(ME, "bad BIOS buffer, phys", bios_buf_phys);
  #if 0
    printf("bios_wini: got buffer size %d, virtual 0x%x, phys 0x%x\n",
    		bios_buf_size, bios_buf_vir, bios_buf_phys);
  #endif
  
    /* Get the geometry of the drives */
    for (drive = 0; drive < MAX_DRIVES; drive++) {
    	if (remap_first)
    	{
    		if (drive == 7)
  			drive_id= 0x80;
  		else
  			drive_id= 0x80 + drive + 1;
    	}
    	else
  		drive_id= 0x80 + drive;
  
  	(void) w_prepare(drive * DEV_PER_DRIVE);
  	wn = w_wn;
  	wn->drive_id= drive_id;
  
  	reg86.u.b.intno = 0x13;
  	reg86.u.b.ah = 0x08;	/* Get drive parameters. */
  	reg86.u.b.dl = drive_id;
  	r= sys_int86(&reg86);
  	if (r != OK)
  		panic(ME, "BIOS call failed", r);
  
  	nr_drives = !(reg86.u.w.f & 0x0001) ? reg86.u.b.dl : drive;
  	if (drive_id >= 0x80 + nr_drives) continue;
  	wn->present= 1;
  
  	wn->heads = reg86.u.b.dh + 1;
  	wn->sectors = reg86.u.b.cl & 0x3F;
  	wn->cylinders = (reg86.u.b.ch | ((reg86.u.b.cl & 0xC0) << 2)) + 1;
  
  	capacity = (unsigned long) wn->cylinders * wn->heads * wn->sectors;
  
  	reg86.u.b.intno = 0x13;
  	reg86.u.b.ah = 0x41;	/* INT 13 Extensions - Installation check */
  	reg86.u.w.bx = 0x55AA;
  	reg86.u.b.dl = drive_id;
  
  	if (pc_at) {
  		r= sys_int86(&reg86);
  		if (r != OK)
  			panic(ME, "BIOS call failed", r);
  	}
  
  	if (!(reg86.u.w.f & 0x0001) && reg86.u.w.bx == 0xAA55
  				&& (reg86.u.w.cx & 0x0001)) {
  		/* INT 13 Extensions available. */
  		i13e_par.len = 0x001E;	/* Input size of parameter packet */
  		r= sys_vircopy(SELF, D, (vir_bytes)&i13e_par,
  			SYSTEM, D, bios_buf_vir, 
  			sizeof(i13e_par));
  		if (r != OK)
  			panic(ME, "sys_vircopy failed\n", r);
  		reg86.u.b.intno = 0x13;
  		reg86.u.b.ah = 0x48;	/* Ext. Get drive parameters. */
  		reg86.u.b.dl = drive_id;
  		reg86.u.w.si = bios_buf_phys % HCLICK_SIZE;
  		reg86.u.w.ds = bios_buf_phys / HCLICK_SIZE;
  
  		r= sys_int86(&reg86);
  		if (r != OK)
  			panic(ME, "BIOS call failed", r);
  
  		r= sys_vircopy(SYSTEM, D, bios_buf_vir,
  			 SELF, D, (vir_bytes)&i13e_par,
  			sizeof(i13e_par));
  		if (r != OK)
  			panic(ME, "sys_vircopy failed\n", r);
  
  		if (!(reg86.u.w.f & 0x0001)) {
  			wn->int13ext = 1;	/* Extensions can be used. */
  			capacity = i13e_par.capacity[0];
  			if (i13e_par.capacity[1] != 0) capacity = 0xFFFFFFFF;
  		}
  	}
  
  	if (wn->int13ext) {
  		printf("%s: %lu sectors\n", w_name(), capacity);
  	} else {
  		printf("%s: %d cylinders, %d heads, %d sectors per track\n",
  			w_name(), wn->cylinders, wn->heads, wn->sectors);
  	}
  	wn->part[0].dv_size = mul64u(capacity, SECTOR_SIZE);
    }
  }
  
  /*============================================================================*
   *				w_geometry				      *
   *============================================================================*/
  PRIVATE void w_geometry(entry)
  struct partition *entry;
  {
    entry->cylinders = w_wn->cylinders;
    entry->heads = w_wn->heads;
    entry->sectors = w_wn->sectors;
  }
  
  /*============================================================================*
   *				w_other				      *
   *============================================================================*/
  PRIVATE int w_other(dr, m)
  struct driver *dr;
  message *m;
  {
          int r, timeout, prev;
  
          if (m->m_type != DEV_IOCTL ) {
                  return EINVAL;
          }
  
  	if (m->REQUEST == DIOCOPENCT) {
                  int count;
                  if (w_prepare(m->DEVICE) == NIL_DEV) return ENXIO;
                  count = w_wn->open_ct;
                  if ((r=sys_datacopy(SELF, (vir_bytes)&count,
                          m->PROC_NR, (vir_bytes)m->ADDRESS, sizeof(count))) != OK)
                          return r;
                  return OK;
          }
  
          return EINVAL;
  }
  
  