Alford, Seth
2009-Jun-30 20:22 UTC
[syslinux] syslinux 3.11 patch for handling both KVM and serial console input
We modified our copy of syslinux. We're now sharing those
modifications. That's so that:
1. We fulfill our requirements under the GPL
2. Our modifications might be picked up and included in the base
code. That way we wouldn't have to make the same
modifications, again, later.
Since we're using CentOS 5.3, and CentOS 5.3 derives from RHEL
5.3, and RHEL 5.3 uses syslinux 3.11, we modified syslinux
version 3.11.
The modification are in the form of a patch, which appears below.
Our Linux systems may have an old-style "green screen" terminal
attached to the serial console. Or they may have a keyboard, VGA
display and mouse (KVM.) Originally, our isolinux menu more or
less offered the user the choices of
1. Install using the KVM
2. Install using the serial terminal
3. Restore from tape using the KVM
4. Restore from tape using the terminal
5. Use rescue mode from the KVM
6. Use rescue mode from the terminal
The user was supposed to input a number, 1 through 6, based on
what the user wanted to do and what type of display the system
had.
We decided that syslinux itself could figure out whether input
came from the KVM or a serial console. So all the user needed to
do was figure out whether to install, restore, or use rescue
mode. That way, the user would only have to figure out a 3 item
menu, rather than a 6 item menu. So now the user sees a menu
which looks more or less like:
If you want to..........type:
Restore.................1
Install.................2
Use rescue mode.........3
The user still inputs a number, 1 through 3.
To make this work, we added a FromFlag byte before the command
line buffer in the syslinux code. If the input came from the
serial terminal, FromFlag got a "-" character (without the
quotes) stored in it. If the input came from the KVM, FromFlag
got a "+" character (without quotes). In the isolinux.cfg menu,
we created entries for +1, -1, +2, -2, +3, and -3, with
appropriate flags for serial console for the "-" entries. The
"1" entries do a restore. The "2" entries do an install.
The
"3" entries put the system into rescue mode. With the patch,
syslinux also tries the user input with the +/- prepended.
Here's the isolinux.cfg menu:
----isolinux.cfg menu starts----
serial 0 38400
prompt 1
timeout 0
display boot.msg
F1 boot.msg
label +1
kernel vmlinuz
append initrd=initrd.img ks=cdrom:isolinux/ks_restore.cfg text
label -1
kernel vmlinuz
append initrd=initrd.img console=ttyS0,38400n8
ks=cdrom:isolinux/ks_restore.cfg text
label +2
kernel vmlinuz
append initrd=initrd.img ks=cdrom:isolinux/ks.cfg text
label -2
kernel vmlinuz
append initrd=initrd.img console=ttyS0,38400n8 ks=cdrom:isolinux/ks.cfg text
label +3
kernel vmlinuz
append rescue initrd=initrd.img text
label -3
kernel vmlinuz
append rescue initrd=initrd.img console=ttyS0,38400n8 text
----isolinux.cfg menu ends----
David Parsons, who is no longer with ADP, did most of the
modifications which made this work.
--Seth Alford
ADP Dealer Services
seth_alford at adp.com
----patch follows----
--- s_yslinux-3.11.orig/conio.inc 2005-08-18 13:53:39.000000000 -0700
+++ s_yslinux-3.11.new/conio.inc 2009-03-19 17:29:55.000000000 -0700
@@ -356,8 +356,10 @@
.serial: xor ah,ah ; Avoid confusion
xchg dx,bx ; Data port
in al,dx
+ mov byte [FromFlag],45 ; '-' flags input from serial
ret
-.kbd: mov ah,10h ; Get keyboard input
+.kbd: mov byte [FromFlag],43 ; '+' flags input from console
+ mov ah,10h ; Get keyboard input
int 16h
cmp al,0E0h
jnz .not_ext
--- s_yslinux-3.11.orig/parseconfig.inc 2005-08-30 15:36:49.000000000 -0700
+++ s_yslinux-3.11.new/parseconfig.inc 2009-03-20 13:51:17.000000000 -0700
@@ -393,6 +393,7 @@
section .latebss
alignb 4 ; For the good of REP MOVSD
+FromFlag resb 1 ; ADP: becomes '-' for serial, '+' for kbd
command_line resb max_cmd_len+2 ; Command line buffer
alignb 4
default_cmd resb max_cmd_len+1 ; "default" command line
--- s_yslinux-3.11.orig/ui.inc 2005-08-30 15:54:14.000000000 -0700
+++ s_yslinux-3.11.new/ui.inc 2009-03-20 15:12:45.000000000 -0700
@@ -196,6 +196,13 @@
; First we need to mangle the kernel name the way DOS would...
;
mov si,command_line
+ call find
+ mov si,FromFlag
+ call find
+ mov si,command_line
+ jmp bad_kernel
+
+find:
mov di,KernelName
push si
push di
@@ -346,6 +353,8 @@
add bx,byte 4
cmp bx,exten_table_end
jna .search_loop ; allow == case (final case)
+ ret
+
; Fall into bad_kernel
;
; bad_kernel: Kernel image not found
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Miller, Shao
2009-Jun-30 21:10 UTC
[syslinux] syslinux 3.11 patch for handling both KVM and serialconsole input
This might be nicer if there was a way to gain this functionality
without requiring all current Syslinux users to rewrite their
config-files.
I believe that core code is being re-worked during a Google Summer of
Code project this summer. With that project's eventual success, perhaps
this could be reconsidered at that time?
- Shao Miller
-----Original Message-----
From: syslinux-bounces at zytor.com [mailto:syslinux-bounces at zytor.com] On
Behalf Of Alford, Seth
Sent: Tuesday, June 30, 2009 16:22
To: syslinux at zytor.com
Subject: [syslinux] syslinux 3.11 patch for handling both KVM and
serialconsole input
We modified our copy of syslinux. We're now sharing those
modifications. That's so that:
1. We fulfill our requirements under the GPL
2. Our modifications might be picked up and included in the base
code. That way we wouldn't have to make the same
modifications, again, later.
Since we're using CentOS 5.3, and CentOS 5.3 derives from RHEL
5.3, and RHEL 5.3 uses syslinux 3.11, we modified syslinux
version 3.11.
The modification are in the form of a patch, which appears below.
Our Linux systems may have an old-style "green screen" terminal
attached to the serial console. Or they may have a keyboard, VGA
display and mouse (KVM.) Originally, our isolinux menu more or
less offered the user the choices of
1. Install using the KVM
2. Install using the serial terminal
3. Restore from tape using the KVM
4. Restore from tape using the terminal
5. Use rescue mode from the KVM
6. Use rescue mode from the terminal
The user was supposed to input a number, 1 through 6, based on
what the user wanted to do and what type of display the system
had.
We decided that syslinux itself could figure out whether input
came from the KVM or a serial console. So all the user needed to
do was figure out whether to install, restore, or use rescue
mode. That way, the user would only have to figure out a 3 item
menu, rather than a 6 item menu. So now the user sees a menu
which looks more or less like:
If you want to..........type:
Restore.................1
Install.................2
Use rescue mode.........3
The user still inputs a number, 1 through 3.
To make this work, we added a FromFlag byte before the command
line buffer in the syslinux code. If the input came from the
serial terminal, FromFlag got a "-" character (without the
quotes) stored in it. If the input came from the KVM, FromFlag
got a "+" character (without quotes). In the isolinux.cfg menu,
we created entries for +1, -1, +2, -2, +3, and -3, with
appropriate flags for serial console for the "-" entries. The
"1" entries do a restore. The "2" entries do an install.
The
"3" entries put the system into rescue mode. With the patch,
syslinux also tries the user input with the +/- prepended.
Here's the isolinux.cfg menu:
----isolinux.cfg menu starts----
serial 0 38400
prompt 1
timeout 0
display boot.msg
F1 boot.msg
label +1
kernel vmlinuz
append initrd=initrd.img ks=cdrom:isolinux/ks_restore.cfg text
label -1
kernel vmlinuz
append initrd=initrd.img console=ttyS0,38400n8
ks=cdrom:isolinux/ks_restore.cfg text
label +2
kernel vmlinuz
append initrd=initrd.img ks=cdrom:isolinux/ks.cfg text
label -2
kernel vmlinuz
append initrd=initrd.img console=ttyS0,38400n8
ks=cdrom:isolinux/ks.cfg text
label +3
kernel vmlinuz
append rescue initrd=initrd.img text
label -3
kernel vmlinuz
append rescue initrd=initrd.img console=ttyS0,38400n8 text
----isolinux.cfg menu ends----
David Parsons, who is no longer with ADP, did most of the
modifications which made this work.
--Seth Alford
ADP Dealer Services
seth_alford at adp.com
----patch follows----
--- s_yslinux-3.11.orig/conio.inc 2005-08-18 13:53:39.000000000
-0700
+++ s_yslinux-3.11.new/conio.inc 2009-03-19 17:29:55.000000000
-0700
@@ -356,8 +356,10 @@
.serial: xor ah,ah ; Avoid confusion
xchg dx,bx ; Data port
in al,dx
+ mov byte [FromFlag],45 ; '-' flags input from serial
ret
-.kbd: mov ah,10h ; Get keyboard input
+.kbd: mov byte [FromFlag],43 ; '+' flags input from console
+ mov ah,10h ; Get keyboard input
int 16h
cmp al,0E0h
jnz .not_ext
--- s_yslinux-3.11.orig/parseconfig.inc 2005-08-30 15:36:49.000000000
-0700
+++ s_yslinux-3.11.new/parseconfig.inc 2009-03-20 13:51:17.000000000
-0700
@@ -393,6 +393,7 @@
section .latebss
alignb 4 ; For the good of REP MOVSD
+FromFlag resb 1 ; ADP: becomes '-' for serial,
'+' for kbd
command_line resb max_cmd_len+2 ; Command line buffer
alignb 4
default_cmd resb max_cmd_len+1 ; "default" command line
--- s_yslinux-3.11.orig/ui.inc 2005-08-30 15:54:14.000000000 -0700
+++ s_yslinux-3.11.new/ui.inc 2009-03-20 15:12:45.000000000 -0700
@@ -196,6 +196,13 @@
; First we need to mangle the kernel name the way DOS would...
;
mov si,command_line
+ call find
+ mov si,FromFlag
+ call find
+ mov si,command_line
+ jmp bad_kernel
+
+find:
mov di,KernelName
push si
push di
@@ -346,6 +353,8 @@
add bx,byte 4
cmp bx,exten_table_end
jna .search_loop ; allow == case (final
case)
+ ret
+
; Fall into bad_kernel
;
; bad_kernel: Kernel image not found
This message and any attachments are intended only for the use of the
addressee and may contain information that is privileged and
confidential. If the reader of the message is not the intended recipient
or an authorized representative of the intended recipient, you are
hereby notified that any dissemination of this communication is strictly
prohibited. If you have received this communication in error, please
notify us immediately by e-mail and delete the message and any
attachments from your system.
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Alford, Seth
2009-Jun-30 23:36 UTC
[syslinux] syslinux 3.11 patch for handling both KVM and serial console input
On Tue, Jun 30, 2009 at 03:22:00PM -0500, Alford, Seth wrote:> We modified our copy of syslinux. We're now sharing those > modifications. That's so that: > > 1. We fulfill our requirements under the GPL > 2. Our modifications might be picked up and included in the base > code. That way we wouldn't have to make the same > modifications, again, later. > > Since we're using CentOS 5.3, and CentOS 5.3 derives from RHEL > 5.3, and RHEL 5.3 uses syslinux 3.11, we modified syslinux > version 3.11. > > The modification are in the form of a patch, which appears below. >I also need to point out, before the lawyers yell at me, that this software is offered with NO WARRANTY and NO SUPPORT of any kind. --Seth This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.