svn commit: r315427 - head/sys/boot/i386/libi386

[Toomas Soome]

Author: tsoome
Date: Thu Mar 16 21:34:14 2017
New Revision: 315427
URL: https://svnweb.freebsd.org/changeset/base/315427

Log:
  loader: biosdisk should report IO error from INT13
  
  We should be more verbose about read errors from biosdisk, except filter
  out the floppy controller errors, which apparently are resulting from
  read attempt from device without the media present.
  
  Reviewed by:	allanjude
  Approved by:	allanjude (mentor)
  Differential Revision:	https://reviews.freebsd.org/D10032

Modified:
  head/sys/boot/i386/libi386/biosdisk.c

Modified: head/sys/boot/i386/libi386/biosdisk.c
==============================================================================
--- head/sys/boot/i386/libi386/biosdisk.c	Thu Mar 16 21:32:05 2017	(r315426)
+++ head/sys/boot/i386/libi386/biosdisk.c	Thu Mar 16 21:34:14 2017	(r315427)
@@ -559,7 +559,7 @@ bd_realstrategy(void *devdata, int rw, d
 {
     struct disk_devdesc *dev = (struct disk_devdesc *)devdata;
     uint64_t		disk_blocks;
-    int			blks;
+    int			blks, rc;
 #ifdef BD_SUPPORT_FRAGS /* XXX: sector size */
     char		fragbuf[BIOSDISK_SECSIZE];
     size_t		fragsize;
@@ -616,8 +616,12 @@ bd_realstrategy(void *devdata, int rw, d
     case F_READ:
 	DEBUG("read %d from %lld to %p", blks, dblk, buf);
 
-	if (blks && bd_read(dev, dblk, blks, buf)) {
-	    DEBUG("read error");
+	if (blks && (rc = bd_read(dev, dblk, blks, buf))) {
+	    /* Filter out floppy controller errors */
+	    if (BD(dev).bd_flags != BD_FLOPPY || rc != 0x20) {
+		printf("read %d from %lld to %p, error: 0x%x", blks, dblk,
+		    buf, rc);
+	    }
 	    return (EIO);
 	}
 #ifdef BD_SUPPORT_FRAGS /* XXX: sector size */
@@ -676,7 +680,9 @@ bd_edd_io(struct disk_devdesc *dev, dadd
     v86.ds = VTOPSEG(&packet);
     v86.esi = VTOPOFF(&packet);
     v86int();
-    return (V86_CY(v86.efl));
+    if (V86_CY(v86.efl))
+	return (v86.eax >> 8);
+    return (0);
 }
 
 static int
@@ -710,7 +716,9 @@ bd_chs_io(struct disk_devdesc *dev, dadd
     v86.es = VTOPSEG(dest);
     v86.ebx = VTOPOFF(dest);
     v86int();
-    return (V86_CY(v86.efl));
+    if (V86_CY(v86.efl))
+	return (v86.eax >> 8);
+    return (0);
 }
 
 static int
@@ -797,7 +805,7 @@ bd_io(struct disk_devdesc *dev, daddr_t 
 	    DEBUG("Read %d sector(s) from %lld to %p (0x%x) %s", x,
 		dblk, p, VTOP(p), result ? "failed" : "ok");
 	if (result) {
-	    return(-1);
+	    return (result);
 	}
 	if (!write && bbuf != NULL)
 	    bcopy(bbuf, p, x * BD(dev).bd_sectorsize);