loader: issue edd probe before legacy ah=08 and detect no media

while probing for drives, use int13 extended info before standard one and
provide workaround for case we are not getting needed information in case
of floppy drive.

In case of INT13 errors, there are (at least) 3 error codes appearing in case
of missin media - 20h, 31h and 80h. Flag the no media and do not print an
error.

Differential Revision:	https://reviews.freebsd.org/D17667

1 files changed, 197 insertions, 79 deletions

diff --git a/stand/i386/libi386/biosdisk.c b/stand/i386/libi386/biosdisk.c
index 02daada4fbfd..e4dfe3ff708e 100644
--- a/stand/i386/libi386/biosdisk.c
+++ b/stand/i386/libi386/biosdisk.c
@@ -43,7 +43,6 @@ __FBSDID("$FreeBSD$");
 #include <stand.h>
 #include <machine/bootinfo.h>
 #include <stdarg.h>
-#include <stdbool.h>
 
 #include <bootstrap.h>
 #include <btxv86.h>
@@ -81,8 +80,10 @@ static struct bdinfo
 #define	BD_MODEINT13	0x0000
 #define	BD_MODEEDD1	0x0001
 #define	BD_MODEEDD3	0x0002
+#define	BD_MODEEDD	(BD_MODEEDD1 | BD_MODEEDD3)
 #define	BD_MODEMASK	0x0003
 #define	BD_FLOPPY	0x0004
+#define	BD_NO_MEDIA	0x0008
 	int		bd_type;	/* BIOS 'drive type' (floppy only) */
 	uint16_t	bd_sectorsize;	/* Sector size */
 	uint64_t	bd_sectors;	/* Disk size */
@@ -188,60 +189,83 @@ bd_init(void)
 }
 
 /*
- * Try to detect a device supported by the legacy int13 BIOS
+ * Return EDD version or 0 if EDD is not supported on this drive.
  */
 static int
-bd_int13probe(struct bdinfo *bd)
+bd_check_extensions(int unit)
 {
-	struct edd_params params;
-	int ret = 1;	/* assume success */
+	/* Determine if we can use EDD with this device. */
+	v86.ctl = V86_FLAGS;
+	v86.addr = 0x13;
+	v86.eax = 0x4100;
+	v86.edx = unit;
+	v86.ebx = 0x55aa;
+	v86int();
+
+	if (V86_CY(v86.efl) ||			/* carry set */
+	    (v86.ebx & 0xffff) != 0xaa55)	/* signature */
+		return (0);
+
+	/* extended disk access functions (AH=42h-44h,47h,48h) supported */
+	if ((v86.ecx & EDD_INTERFACE_FIXED_DISK) == 0)
+		return (0);
 
+	return ((v86.eax >> 8) & 0xff);
+}
+
+static void
+bd_reset_disk(int unit)
+{
+	/* reset disk */
+	v86.ctl = V86_FLAGS;
+	v86.addr = 0x13;
+	v86.eax = 0;
+	v86.edx = unit;
+	v86int();
+}
+
+/*
+ * Read CHS info. Return 0 on success, error otherwise.
+ */
+static int
+bd_get_diskinfo_std(struct bdinfo *bd)
+{
+	bzero(&v86, sizeof(v86));
 	v86.ctl = V86_FLAGS;
 	v86.addr = 0x13;
 	v86.eax = 0x800;
 	v86.edx = bd->bd_unit;
 	v86int();
 
-	/* Don't error out if we get bad sector number, try EDD as well */
-	if (V86_CY(v86.efl) ||	/* carry set */
-	    (v86.edx & 0xff) <= (unsigned)(bd->bd_unit & 0x7f))	/* unit # bad */
-		return (0);	/* skip device */
+	if (V86_CY(v86.efl) && ((v86.eax & 0xff00) != 0))
+		return ((v86.eax & 0xff00) >> 8);
 
-	if ((v86.ecx & 0x3f) == 0)	/* absurd sector number */
-		ret = 0;	/* set error */
+	/* return custom error on absurd sector number */
+	if ((v86.ecx & 0x3f) == 0)
+		return (0x60);
 
-	/* Convert max cyl # -> # of cylinders */
 	bd->bd_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
 	/* Convert max head # -> # of heads */
 	bd->bd_hds = ((v86.edx & 0xff00) >> 8) + 1;
 	bd->bd_sec = v86.ecx & 0x3f;
-	bd->bd_type = v86.ebx & 0xff;
-	bd->bd_flags |= BD_MODEINT13;
+	bd->bd_type = v86.ebx;
+	bd->bd_sectors = (uint64_t)bd->bd_cyl * bd->bd_hds * bd->bd_sec;
 
-	/* Calculate sectors count from the geometry */
-	bd->bd_sectors = bd->bd_cyl * bd->bd_hds * bd->bd_sec;
-	bd->bd_sectorsize = BIOSDISK_SECSIZE;
-	DEBUG("unit 0x%x geometry %d/%d/%d", bd->bd_unit, bd->bd_cyl,
-	    bd->bd_hds, bd->bd_sec);
+	return (0);
+}
+
+/*
+ * Read EDD info. Return 0 on success, error otherwise.
+ */
+static int
+bd_get_diskinfo_ext(struct bdinfo *bd)
+{
+	struct edd_params params;
+	uint64_t total;
 
-	/* Determine if we can use EDD with this device. */
-	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	v86.eax = 0x4100;
-	v86.edx = bd->bd_unit;
-	v86.ebx = 0x55aa;
-	v86int();
-	if (V86_CY(v86.efl) ||	/* carry set */
-	    (v86.ebx & 0xffff) != 0xaa55 || /* signature */
-	    (v86.ecx & EDD_INTERFACE_FIXED_DISK) == 0)
-		return (ret);	/* return code from int13 AH=08 */
-
-	/* EDD supported */
-	bd->bd_flags |= BD_MODEEDD1;
-	if ((v86.eax & 0xff00) >= 0x3000)
-		bd->bd_flags |= BD_MODEEDD3;
 	/* Get disk params */
-	params.len = sizeof(struct edd_params);
+	bzero(&params, sizeof(params));
+	params.len = sizeof(params);
 	v86.ctl = V86_FLAGS;
 	v86.addr = 0x13;
 	v86.eax = 0x4800;
@@ -249,37 +273,120 @@ bd_int13probe(struct bdinfo *bd)
 	v86.ds = VTOPSEG(&params);
 	v86.esi = VTOPOFF(&params);
 	v86int();
-	if (!V86_CY(v86.efl)) {
-		uint64_t total;
 
-		/*
-		 * Sector size must be a multiple of 512 bytes.
-		 * An alternate test would be to check power of 2,
-		 * powerof2(params.sector_size).
-		 * 4K is largest read buffer we can use at this time.
-		 */
-		if (params.sector_size >= 512 &&
-		    params.sector_size <= 4096 &&
-		    (params.sector_size % BIOSDISK_SECSIZE) == 0)
-			bd->bd_sectorsize = params.sector_size;
-
-		total = bd->bd_sectorsize * params.sectors;
-		if (params.sectors != 0) {
-			/* Only update if we did not overflow. */
-			if (total > params.sectors)
-				bd->bd_sectors = params.sectors;
-		}
+	if (V86_CY(v86.efl) && ((v86.eax & 0xff00) != 0))
+		return ((v86.eax & 0xff00) >> 8);
+
+	/*
+	 * Sector size must be a multiple of 512 bytes.
+	 * An alternate test would be to check power of 2,
+	 * powerof2(params.sector_size).
+	 * 4K is largest read buffer we can use at this time.
+	 */
+	if (params.sector_size >= 512 &&
+	    params.sector_size <= 4096 &&
+	    (params.sector_size % BIOSDISK_SECSIZE) == 0)
+		bd->bd_sectorsize = params.sector_size;
 
+	bd->bd_cyl = params.cylinders;
+	bd->bd_hds = params.heads;
+	bd->bd_sec = params.sectors_per_track;
+
+	if (params.sectors != 0) {
+		total = params.sectors;
+	} else {
 		total = (uint64_t)params.cylinders *
 		    params.heads * params.sectors_per_track;
-		if (total > 0 && bd->bd_sectors > total)
-			bd->bd_sectors = total;
+	}
+	bd->bd_sectors = total;
 
-		ret = 1;
+	return (0);
+}
+
+/*
+ * Try to detect a device supported by the legacy int13 BIOS
+ */
+static int
+bd_int13probe(struct bdinfo *bd)
+{
+	int edd;
+	int ret;
+
+	bd->bd_flags &= ~BD_NO_MEDIA;
+
+	edd = bd_check_extensions(bd->bd_unit);
+	if (edd == 0)
+		bd->bd_flags |= BD_MODEINT13;
+	else if (edd < 0x30)
+		bd->bd_flags |= BD_MODEEDD1;
+	else
+		bd->bd_flags |= BD_MODEEDD3;
+
+	/* Default sector size */
+	bd->bd_sectorsize = BIOSDISK_SECSIZE;
+
+	/*
+	 * Test if the floppy device is present, so we can avoid receiving
+	 * bogus information from bd_get_diskinfo_std().
+	 */
+	if (bd->bd_unit < 0x80) {
+		/* reset disk */
+		bd_reset_disk(bd->bd_unit);
+
+		/* Get disk type */
+		v86.ctl = V86_FLAGS;
+		v86.addr = 0x13;
+		v86.eax = 0x1500;
+		v86.edx = bd->bd_unit;
+		v86int();
+		if (V86_CY(v86.efl) || (v86.eax & 0x300) == 0)
+			return (0);
 	}
-	DEBUG("unit 0x%x flags %x, sectors %llu, sectorsize %u",
-	    bd->bd_unit, bd->bd_flags, bd->bd_sectors, bd->bd_sectorsize);
-	return (ret);
+
+	ret = 1;
+	if (edd != 0)
+		ret = bd_get_diskinfo_ext(bd);
+	if (ret != 0 || bd->bd_sectors == 0)
+		ret = bd_get_diskinfo_std(bd);
+
+	if (ret != 0 && bd->bd_unit < 0x80) {
+		/* Set defaults for 1.44 floppy */
+		bd->bd_cyl = 80;
+		bd->bd_hds = 2;
+		bd->bd_sec = 18;
+		bd->bd_type = 4;
+		bd->bd_sectors = 2880;
+		/* Since we are there, there most likely is no media */
+		bd->bd_flags |= BD_NO_MEDIA;
+		ret = 0;
+	}
+
+	if (ret != 0) {
+		if (bd->bd_sectors != 0 && edd != 0) {
+			bd->bd_sec = 63;
+			bd->bd_hds = 255;
+			bd->bd_cyl =
+			    (bd->bd_sectors + bd->bd_sec * bd->bd_hds - 1) /
+			    bd->bd_sec * bd->bd_hds;
+		} else {
+			printf("Can not get information about %s unit %#x\n",
+			    biosdisk.dv_name, bd->bd_unit);
+			return (0);
+		}
+	}
+
+	if (bd->bd_sec == 0)
+		bd->bd_sec = 63;
+	if (bd->bd_hds == 0)
+		bd->bd_hds = 255;
+
+	if (bd->bd_sectors == 0)
+		bd->bd_sectors = (uint64_t)bd->bd_cyl * bd->bd_hds * bd->bd_sec;
+
+	DEBUG("unit 0x%x geometry %d/%d/%d", bd->bd_unit, bd->bd_cyl,
+	    bd->bd_hds, bd->bd_sec);
+
+	return (1);
 }
 
 /*
@@ -301,9 +408,11 @@ bd_print(int verbose)
 
 	for (i = 0; i < nbdinfo; i++) {
 		snprintf(line, sizeof(line),
-		    "    disk%d:   BIOS drive %c (%ju X %u):\n", i,
+		    "    disk%d:   BIOS drive %c (%s%ju X %u):\n", i,
 		    (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit):
 		    ('C' + bdinfo[i].bd_unit - 0x80),
+		    (bdinfo[i].bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA ?
+		    "no media, " : "",
 		    (uintmax_t)bdinfo[i].bd_sectors,
 		    bdinfo[i].bd_sectorsize);
 		if ((ret = pager_output(line)) != 0)
@@ -351,6 +460,11 @@ bd_open(struct open_file *f, ...)
 
 	if (dev->dd.d_unit < 0 || dev->dd.d_unit >= nbdinfo)
 		return (EIO);
+
+	if ((BD(dev).bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA) {
+		if (!bd_int13probe(&BD(dev)))
+			return (EIO);
+	}
 	BD(dev).bd_open++;
 	if (BD(dev).bd_bcache == NULL)
 	    BD(dev).bd_bcache = bcache_allocate();
@@ -499,7 +613,7 @@ bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
 	 * partition.
 	 */
 	if (disk_ioctl(dev, DIOCGMEDIASIZE, &disk_blocks) == 0) {
-		/* DIOCGMEDIASIZE returns bytes. */
+		/* DIOCGMEDIASIZE does return bytes. */
 		disk_blocks /= BD(dev).bd_sectorsize;
 	} else {
 		/* We should not get here. Just try to survive. */
@@ -685,29 +799,33 @@ bd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
 	if (dowrite == BD_RD && dblk >= 0x100000000)
 		bd_io_workaround(dev);
 	for (retry = 0; retry < 3; retry++) {
-		/* if retrying, reset the drive */
-		if (retry > 0) {
-			v86.ctl = V86_FLAGS;
-			v86.addr = 0x13;
-			v86.eax = 0;
-			v86.edx = BD(dev).bd_unit;
-			v86int();
-		}
-
-		if (BD(dev).bd_flags & BD_MODEEDD1)
+		if (BD(dev).bd_flags & BD_MODEEDD)
 			result = bd_edd_io(dev, dblk, blks, dest, dowrite);
 		else
 			result = bd_chs_io(dev, dblk, blks, dest, dowrite);
 
-		if (result == 0)
+		if (result == 0) {
+			if (BD(dev).bd_flags & BD_NO_MEDIA)
+				BD(dev).bd_flags &= ~BD_NO_MEDIA;
+			break;
+		}
+
+		bd_reset_disk(BD(dev).bd_unit);
+
+		/*
+		 * Error codes:
+		 * 20h	controller failure
+		 * 31h	no media in drive (IBM/MS INT 13 extensions)
+		 * 80h	no media in drive, VMWare (Fusion)
+		 * There is no reason to repeat the IO with errors above.
+		 */
+		if (result == 0x20 || result == 0x31 || result == 0x80) {
+			BD(dev).bd_flags |= BD_NO_MEDIA;
 			break;
+		}
 	}
 
-	/*
-	 * 0x20 - Controller failure. This is common error when the
-	 * media is not present.
-	 */
-	if (result != 0 && result != 0x20) {
+	if (result != 0 && (BD(dev).bd_flags & BD_NO_MEDIA) == 0) {
 		if (dowrite == BD_WR) {
 			printf("%s%d: Write %d sector(s) from %p (0x%x) "
 			    "to %lld: 0x%x\n", dev->dd.d_dev->dv_name,