EDD: use EXTENDED READ command, add CONFIG_EDD_SKIP_MBR
PATCH 1/1 EDD: use EXTENDED READ command, add CONFIG_EDD_SKIP_MBR
Some controller BIOSes have problems with the legacy int13 fn02 READ SECTORS command. int13 fn42 EXTENDED READ is used in preference by most boot loaders today, so lets use that. If EXTENDED READ fails or isn't supported, fall back to READ SECTORS.
This hopefully resolves the three reports of BIOSes which would either long-pause (30+ seconds) or hang completely on the legacy READ SECTORS command.
This also adds CONFIG_EDD_SKIP_MBR to eliminate reading the MBR on each BIOS-presented disk, in case there are further problems in this area.
Signature · 240 lines
Matt Domsch
Sr. Software Engineer, Lead Engineer
Dell Linux Solutions linux.dell.com & www.dell.com/linux
Linux on Dell mailing lists @ http://lists.us.dell.com
--- linux-2.6.9-rc3-mm2/include/linux/edd.h Sat Aug 14 00:36:12 2004
+++ linux-2.5-edd/include/linux/edd.h Mon Oct 4 15:20:54 2004
@@ -37,14 +37,18 @@
#define EDDEXTSIZE 8 /* change these if you muck with the structures */
#define EDDPARMSIZE 74
#define CHECKEXTENSIONSPRESENT 0x41
+#define EXTENDEDREAD 0x42
#define GETDEVICEPARAMETERS 0x48
#define LEGACYGETDEVICEPARAMETERS 0x08
#define EDDMAGIC1 0x55AA
#define EDDMAGIC2 0xAA55
+#define FIXEDDISKSUBSET 0x0001
+#define GET_DEVICE_PARAMETERS_SUPPORTED 0x0007
#define READ_SECTORS 0x02 /* int13 AH=0x02 is READ_SECTORS command */
#define EDD_MBR_SIG_OFFSET 0x1B8 /* offset of signature in the MBR */
+#define EDD_DEV_ADDR_PACKET_LEN 0x10 /* for int13 fn42 */
#define EDD_MBR_SIG_BUF 0x290 /* addr in boot params */
#define EDD_MBR_SIG_MAX 16 /* max number of signatures to store */
#define EDD_MBR_SIG_NR_BUF 0x1ea /* addr of number of MBR signtaures at EDD_MBR_SIG_BUF
--- linux-2.6.9-rc3-mm2/drivers/firmware/Kconfig Mon Oct 4 15:18:12 2004
+++ linux-2.5-edd/drivers/firmware/Kconfig Mon Oct 4 15:20:08 2004
@@ -18,6 +18,17 @@ config EDD
obscure configurations. Most disk controller BIOS vendors do
not yet implement this feature.
+config EDD_SKIP_MBR
+ bool "EDD: Skip Master Boot Record read"
+ depends on EDD
+ default n
+ help
+ Most controller BIOSs properly implement real-mode legacy
+ READ SECTORS commands. A few don't.
+
+ If your controller hangs during the kernel's real-mode
+ startup routine, say Y here.
+
config EFI_VARS
tristate "EFI Variable Support via sysfs"
depends on EFI
--- linux-2.6.9-rc3-mm2/arch/i386/boot/edd.S 2004-10-04 15:47:20.000000000 -0500
+++ linux-2.5-edd/arch/i386/boot/edd.S 2004-10-04 15:45:37.000000000 -0500
@@ -7,20 +7,66 @@
* and Andrew Wilks <[email protected]> September 2003, June 2004
* legacy CHS retreival by Patrick J. LoPresti <[email protected]>
* March 2004
+ * Use EXTENDED READ calls if possible, Matt Domsch, October 2004
*/
#include <linux/edd.h>
#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
-# Read the first sector of each BIOS disk device and store the 4-byte signature
-edd_mbr_sig_start:
movb $0, (EDD_MBR_SIG_NR_BUF) # zero value at EDD_MBR_SIG_NR_BUF
+#ifndef(CONFIG_EDD_SKIP_MBR)
+ xorl %edx, %edx
movb $0x80, %dl # from device 80
- movw $EDD_MBR_SIG_BUF, %bx # store buffer ptr in bx
-edd_mbr_sig_read:
- movl $0xFFFFFFFF, %eax
- movl %eax, (%bx) # assume failure
- pushw %bx
+
+edd_mbr_check_ext:
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
+ movb $CHECKEXTENSIONSPRESENT, %ah # Function 41
+ movw $EDDMAGIC1, %bx # magic
+ pushw %dx # work around buggy BIOSes
+ stc # work around buggy BIOSes
+ int $0x13 # make the call
+ sti # work around buggy BIOSes
+ popw %dx
+ jc edd_start # no more BIOS devices
+ cmpw $EDDMAGIC2, %bx # is magic right?
+ jne edd_mbr_sig_next # nope, next...
+ testw $FIXEDDISKSUBSET, %cx # EXTENDED READ supported?
+ jz edd_mbr_read_sectors # nope, use READ SECTORS
+
+edd_mbr_extended_read:
+# Fill out the device address packet here, make the fn42 call
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
+ subw $EDD_DEV_ADDR_PACKET_LEN, %sp # put packet on stack
+ pushw %si
+ movw %sp, %si
+ movl $0, (%si) # zero out packet
+ movl $0, 4(%si)
+ movl $0, 8(%si)
+ movl $0, 12(%si)
+ movb $EDD_DEV_ADDR_PACKET_LEN, (%si) # length of packet
+ movb $1, 2(%si) # move 1 sector
+ movw $EDDBUF, 4(%si) # into EDDBUF
+ movw %ds, 6(%si) # EDDBUF seg is ds
+ movb $EXTENDEDREAD, %ah
+ pushw %dx # work around buggy BIOSes
+ stc # work around buggy BIOSes
+ int $0x13
+ sti # work around buggy BIOSes
+ popw %dx
+ popw %si
+ addw $EDD_DEV_ADDR_PACKET_LEN, %sp # remove packet from stack
+ jnc edd_mbr_store_sig
+ # otherwise, fall through to the legacy read function
+
+edd_mbr_read_sectors:
+# Read the first sector of each BIOS disk device and store the 4-byte signature
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
movb $READ_SECTORS, %ah
movb $1, %al # read 1 sector
movb $0, %dh # at head 0
@@ -28,23 +74,31 @@ edd_mbr_sig_read:
pushw %es
pushw %ds
popw %es
- movw $EDDBUF, %bx # disk's data goes into EDDBUF
- pushw %dx # work around buggy BIOSes
- stc # work around buggy BIOSes
+ movw $EDDBUF, %bx # disk's data goes into EDDBUF
+ pushw %dx # work around buggy BIOSes
+ stc # work around buggy BIOSes
int $0x13
- sti # work around buggy BIOSes
+ sti # work around buggy BIOSes
popw %dx
popw %es
- popw %bx
jc edd_mbr_sig_done # on failure, we're done.
+
+edd_mbr_store_sig:
+ xorl %ebx, %ebx # clear ebx
+ movb %dl, %bl # copy drive number to ebx
+ sub $0x80, %bl # subtract 80h from drive number
+ shlw $2, %bx # multiply by 4
+ addw $EDD_MBR_SIG_BUF, %bx # add to sig_buf
+ # bx now points to the right sig slot
movl (EDDBUF+EDD_MBR_SIG_OFFSET), %eax # read sig out of the MBR
movl %eax, (%bx) # store success
incb (EDD_MBR_SIG_NR_BUF) # note that we stored something
+edd_mbr_sig_next:
incb %dl # increment to next device
- addw $4, %bx # increment sig buffer ptr
cmpb $EDD_MBR_SIG_MAX, (EDD_MBR_SIG_NR_BUF) # Out of space?
- jb edd_mbr_sig_read # keep looping
+ jb edd_mbr_check_ext # keep looping
edd_mbr_sig_done:
+#endif
# Do the BIOS Enhanced Disk Drive calls
# This consists of two calls:
@@ -77,12 +131,35 @@ edd_start:
movw $EDDBUF+EDDEXTSIZE, %si # in ds:si, fn41 results
# kept just before that
movb $0, (EDDNR) # zero value at EDDNR
+ xorl %edx, %edx
movb $0x80, %dl # BIOS device 0x80
edd_check_ext:
+ pushw %di # zero out this edd_info block
+ pushw %es
+ movw %ds, %ax
+ movw %ax, %es
+ movw %si, %ax
+ subw $EDDEXTSIZE, %ax
+ movw %ax, %di
+ movl $EDDEXTSIZE+EDDPARMSIZE, %ecx
+ xorl %eax, %eax
+ cld
+ rep
+ stosb
+ popw %es
+ popw %di
+
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
movb $CHECKEXTENSIONSPRESENT, %ah # Function 41
movw $EDDMAGIC1, %bx # magic
+ pushw %dx # work around buggy BIOSes
+ stc # work around buggy BIOSes
int $0x13 # make the call
+ sti # work around buggy BIOSes
+ popw %dx
jc edd_done # no more BIOS devices
cmpw $EDDMAGIC2, %bx # is magic right?
@@ -93,25 +170,38 @@ edd_check_ext:
movw %cx, %ds:-6(%si) # store extensions
incb (EDDNR) # note that we stored something
+ testw $GET_DEVICE_PARAMETERS_SUPPORTED, %cx
+ jz edd_get_legacy_chs # nope, skip fn48
+
edd_get_device_params:
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
movw $EDDPARMSIZE, %ds:(%si) # put size
- movw $0x0, %ds:2(%si) # work around buggy BIOSes
movb $GETDEVICEPARAMETERS, %ah # Function 48
+ pushw %dx # work around buggy BIOSes
+ stc # work around buggy BIOSes
int $0x13 # make the call
+ sti # work around buggy BIOSes
+ popw %dx
# Don't check for fail return
# it doesn't matter.
edd_get_legacy_chs:
- xorw %ax, %ax
+ xorl %eax, %eax
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
movw %ax, %ds:-4(%si)
movw %ax, %ds:-2(%si)
- # Ralf Brown's Interrupt List says to set ES:DI to
+ # Ralf Brown's Interrupt List says to set ES:DI to
# 0000h:0000h "to guard against BIOS bugs"
- pushw %es
+ pushw %es
movw %ax, %es
movw %ax, %di
pushw %dx # legacy call clobbers %dl
movb $LEGACYGETDEVICEPARAMETERS, %ah # Function 08
+ stc # work around buggy BIOSes
int $0x13 # make the call
+ sti # work around buggy BIOSes
jc edd_legacy_done # failed
movb %cl, %al # Low 6 bits are max
andb $0x3F, %al # sector numberQuoted 5 lines · Matt Domsch
Some controller BIOSes have problems with the legacy int13 fn02 READ SECTORS command. int13 fn42 EXTENDED READ is used in preference by most boot loaders today, so lets use that. If EXTENDED READ fails or isn't supported, fall back to READ SECTORS.
Quoted 7 lines
This hopefully resolves the three reports of BIOSes which would either long-pause (30+ seconds) or hang completely on the legacy READ SECTORS command.
This also adds
CONFIG_EDD_SKIP_MBRto eliminate reading the MBR on each BIOS-presented disk, in case there are further problems in this area.
Build fails on x86-64:
[...]
SYSMAP System.map SYSMAP .tmp_System.map AS arch/x86_64/boot/setup.o
In file included from arch/x86_64/boot/setup.S:536:arch/i386/boot/edd.S:17: macro names must be identifiers make[1]: *** [arch/x86_64/boot/setup.o] Error 1
make: *** [bzImage] Error 2
Quoted 8 lines · Jeff Garzik
Quoted 4 lines
This also adds
CONFIG_EDD_SKIP_MBRto eliminate reading the MBR on each BIOS-presented disk, in case there are further problems in this area.Build fails on x86-64:
Quoted 8 lines
[...]
SYSMAP System.map SYSMAP .tmp_System.map AS arch/x86_64/boot/setup.oIn file included from
arch/x86_64/boot/setup.S:536:
arch/i386/boot/edd.S:17: macro names must be identifiers make[1]: *** [arch/x86_64/boot/setup.o] Error 1
make: *** [bzImage] Error 2
hm, works OK here.
Is it missing config.h?
Quoted 18 lines · Andrew Morton
Quoted 8 lines · Jeff Garzik
Quoted 4 lines
This also adds
CONFIG_EDD_SKIP_MBRto eliminate reading the MBR on each BIOS-presented disk, in case there are further problems in this area.Build fails on x86-64:
Quoted 8 lines
[...]
SYSMAP System.map SYSMAP .tmp_System.map AS arch/x86_64/boot/setup.oIn file included from
arch/x86_64/boot/setup.S:536:
arch/i386/boot/edd.S:17: macro names must be identifiers make[1]: *** [arch/x86_64/boot/setup.o] Error 1
make: *** [bzImage] Error 2
Quoted 3 lines
hm, works OK here.
Is it missing
config.h?
Maybe I was being foolish by applying the patch to mainline ;-)
Jeff
Quoted 4 lines · Jeff Garzik
Quoted 2 lines
Quoted 1 line · Jeff Garzik
arch/i386/boot/edd.S:17: macro names must be identifiersMaybe I was being foolish by applying the patch to mainline ;-)
I tested it on x86 mainline. My x86_64 boxes are in disrepair due to other work, but I'll build it there tomorrow myself...
-Matt
Signature · 4 lines
Matt Domsch Sr. Software Engineer, Lead Engineer Dell Linux Solutions linux.dell.com & www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com
Quoted 18 lines · Andrew Morton
Quoted 8 lines · Jeff Garzik
Quoted 4 lines
This also adds
CONFIG_EDD_SKIP_MBRto eliminate reading the MBR on each BIOS-presented disk, in case there are further problems in this area.Build fails on x86-64:
Quoted 8 lines
[...]
SYSMAP System.map SYSMAP .tmp_System.map AS arch/x86_64/boot/setup.oIn file included from
arch/x86_64/boot/setup.S:536:
arch/i386/boot/edd.S:17: macro names must be identifiers make[1]: *** [arch/x86_64/boot/setup.o] Error 1
make: *** [bzImage] Error 2
Quoted 3 lines
hm, works OK here.
Is it missing
config.h?
No, that's pulled in by setup.S which #includes edd.S, on both i386 and x86_64. Jeff, is it the parens around CONFIG_EDD_SKIP_MBR on that line somehow?
--
Matt Domsch
Sr. Software Engineer, Lead Engineer
Dell Linux Solutions linux.dell.com & www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com
I found the problem ;-)
-#ifndef(CONFIG_EDD_SKIP_MBR)
+#ifndef CONFIG_EDD_SKIP_MBR
Alas, this does not eliminate the 30-second delay on my box.
Just to re-emphasize, I feel a particularly relevant detail is that my VIA-based Athlon64 box has _all_ PATA ports disabled.
I am fairly certainly that the delay did not exist when I enabled at least one PATA port, and I can verify this if you would like.
Jeff
Quoted 1 line · Jeff Garzik
Alas, this does not eliminate the 30-second delay on my box.
OK, thanks for trying. So it's not the READ SECTORS call itself that's the problem.
Quoted 5 lines
Just to re-emphasize, I feel a particularly relevant detail is that my VIA-based Athlon64 box has _all_ PATA ports disabled.
I am fairly certainly that the delay did not exist when I enabled at least one PATA port, and I can verify this if you would like.
Yeah, that'd be good to know. The PATA controller doesn't show up in your lspci results from 5 July, so I'm sure you had it turned off then too.
BIOS reports having 4 disks in your system. Does that match what you would expect?
Your boot disk is on this Promise controller, yes? 00:0d.0 RAID bus controller: Promise Technology, Inc. PDC20378 (SATA150 TX) (rev 02)
The second disk is on a different controller though, with its own EDD 3.0-compliant BIOS.
00:0f.0 RAID bus controller: VIA Technologies,
Inc. VIA VT6420 SATA
RAID Controller (rev 80)
Subsystem: Micro-Star International Co., Ltd. MSI Neo K8T FIS2R mainboard
Then BIOS says you've got two more disks.
Both disks 82 and 83 look remarkably small (20808 sectors each, ~10MB). And I would bet there's no media present, as there's no mbr_signature field given... So BIOS says there's a disk there, but there really isn't. Which could cause the kind of timeout you're seeing. To what are these attached? It's the BIOS for this controller that's probably what's lying.
Thanks,
Matt
Signature · 4 lines
Matt Domsch Sr. Software Engineer, Lead Engineer Dell Linux Solutions linux.dell.com & www.dell.com/linux Linux on Dell mailing lists @ http://lists.us.dell.com
Quoted 32 lines · Matt Domsch
Quoted 1 line · Jeff Garzik
Alas, this does not eliminate the 30-second delay on my box.
OK, thanks for trying. So it's not the READ SECTORS call itself that's the problem.
Quoted 3 lines
Just to re-emphasize, I feel a particularly relevant detail is that my VIA-based Athlon64 box has _all_ PATA ports disabled.
I am fairly certainly that the delay did not exist when I enabled at least one PATA port, and I can verify this if you would like.
Yeah, that'd be good to know. The PATA controller doesn't show up in your lspci results from 5 July, so I'm sure you had it turned off then too.
BIOS reports having 4 disks in your system. Does that match what you would expect?
Your boot disk is on this Promise controller, yes? 00:0d.0 RAID bus controller: Promise Technology, Inc. PDC20378 (SATA150 TX) (rev 02)
The second disk is on a different controller though, with its own EDD 3.0-compliant BIOS.
00:0f.0 RAID bus controller: VIA Technologies,
Inc. VIA VT6420 SATA
RAID Controller (rev 80)
Subsystem: Micro-Star International Co., Ltd. MSI Neo K8T FIS2R mainboard
Quoted 7 lines
Then BIOS says you've got two more disks.
Both disks 82 and 83 look remarkably small (20808 sectors each, ~10MB). And I would bet there's no media present, as there's nombr_signaturefield given... So BIOS says there's a disk there, but there really isn't. Which could cause the kind of timeout you're seeing. To what are these attached? It's the BIOS for this controller that's probably what's lying.
One SATA disk is attached to the Promise SATA controller, and one SATA disk is attached to the VIA SATA controller.
I _think_ the Promise controller boots first, but I could be wrong.
I'll try enabling a PATA port sometime when it isn't 1:30am :)
Jeff