svn commit: r342785 - head/stand/i386/libi386
Toomas Soome
tsoome at FreeBSD.org
Sat Jan 5 07:20:01 UTC 2019
Author: tsoome
Date: Sat Jan 5 07:20:00 2019
New Revision: 342785
URL: https://svnweb.freebsd.org/changeset/base/342785
Log:
With buggy int13 ah=15, we can mis-identify the floppy devices.
We have no option than trust INT13 ah=08 return code during the init phase.
PR: 234460
Reported by: Oleh Hushchenkov
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D18723
Modified:
head/stand/i386/libi386/biosdisk.c
Modified: head/stand/i386/libi386/biosdisk.c
==============================================================================
--- head/stand/i386/libi386/biosdisk.c Sat Jan 5 05:50:16 2019 (r342784)
+++ head/stand/i386/libi386/biosdisk.c Sat Jan 5 07:20:00 2019 (r342785)
@@ -136,6 +136,8 @@ static int bd_ioctl(struct open_file *f, u_long cmd, v
static int bd_print(int verbose);
static int cd_print(int verbose);
static int fd_print(int verbose);
+static void bd_reset_disk(int);
+static int bd_get_diskinfo_std(struct bdinfo *);
struct devsw biosfd = {
.dv_name = "fd",
@@ -252,20 +254,52 @@ bd_unit2bios(struct i386_devdesc *dev)
}
/*
+ * Use INT13 AH=15 - Read Drive Type.
+ */
+static int
+fd_count(void)
+{
+ int drive;
+
+ for (drive = 0; drive < MAXBDDEV; drive++) {
+ bd_reset_disk(drive);
+
+ v86.ctl = V86_FLAGS;
+ v86.addr = 0x13;
+ v86.eax = 0x1500;
+ v86.edx = drive;
+ v86int();
+
+ if (V86_CY(v86.efl))
+ break;
+
+ if ((v86.eax & 0x300) == 0)
+ break;
+ }
+
+ return (drive);
+}
+
+/*
* Quiz the BIOS for disk devices, save a little info about them.
*/
static int
fd_init(void)
{
- int unit;
+ int unit, numfd;
bdinfo_t *bd;
- for (unit = 0; unit < MAXBDDEV; unit++) {
+ numfd = fd_count();
+ for (unit = 0; unit < numfd; unit++) {
if ((bd = calloc(1, sizeof(*bd))) == NULL)
break;
+
+ bd->bd_sectorsize = BIOSDISK_SECSIZE;
bd->bd_flags = BD_FLOPPY;
bd->bd_unit = unit;
- if (!bd_int13probe(bd)) {
+
+ /* Use std diskinfo for floppy drive */
+ if (bd_get_diskinfo_std(bd) != 0) {
free(bd);
break;
}
@@ -382,6 +416,10 @@ bc_add(int biosdev)
static int
bd_check_extensions(int unit)
{
+ /* do not use ext calls for floppy devices */
+ if (unit < 0x80)
+ return (0);
+
/* Determine if we can use EDD with this device. */
v86.ctl = V86_FLAGS;
v86.addr = 0x13;
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