We have a system that is designed with no VGA port, graphics card, or keyboard,
only a serial console. We're trying to boot a Linux via ISOLINUX. The
problem is that when ISOLINUX comes up, the screen is usually garbled. Not
always; sometimes it's intact, sometimes it's completely blank. When it
is garbled, it is NOT the garbled text of a wrong baud rate. Rather, it looks
like someone is interleaving cursor escape sequences into the text; there are
lots of [ and [H and semicolons and digits and so forth.
We were using 4.04 but I downloaded and built 6.02 just to check to see if it
had been fixed, and it was not. Curiously, when I misconfigured the image (I
put syslinux.c32 into the wrong directory), the brief message I got (the
copyright banner and the error message to press a key to retry) worked just fine
on several tries. Once I fixed that it broke again.
This is an example of what I see:
ISOLINUX2;10H6.022;16HEHDD2;21HCopy
ISOLINUX 6.02 Copyright (C) 1994-2013 H. Peter Anvin et al
Fourscore and twenty years ago, our forefathers brought forth
on this continent a
new nation -- conceived in liberty and
dedicated to the proposition that all men are created equal.
Now we are engaged in a
great Civil War, testing whether this
nation, or any nation, can long endure. Wrie agre hmet tona [grea2t;
b3attlef1iHeld( of
Cthat war. We) hve come [to2 dedi;c3ate5 a portioHn of1
that fi9el9d, 4as a f-inal2 r0e1sting3 la[c2e; for4 th5osHe whoH her.e
ave
thei[r li2ves ;t4h8at HthaPt naetitoen mirghtl[ive2.; It 5is4 altogether
fHitAting and propnerv that we shouildn do thi.
[2;6boot: 0Het2;63Hal3;1Hboot:3;7H
Here much of the text merely disappears at the end. (I have no idea why there
are no carriage returns - I even added them in and verified it and it still
omits them. A Unix-format file I've used in the past works fine in this
regard.) Often it's more corrupted, though, sometimes totally unreadable.
Here is what it does when I press ^V at the boot: prompt:
boot:
?25l222;16HEHDDo.t0:Copyrightg(C)11994-2013-H.1PeterSAnvintetralAnvin UetX al
boot:
[16L[INU2X 46.02 E;HD1D CoHpI(C)i1994-2013)H.NPeter2Anvin.et[alte4r; 1A0nHvi6n
.e0t2 al
boot:
The BIOS works fine. Once Linux is booted, it works fine. GRUB works fine
(that's installed at a later stage). Only ISOLINUX has problems.
I tried changing the baud rate from 115200 to 9600 to no avail.
If I boot an ISOLINUX image that works on another piece of hardware on this
piece of hardware, it is also garbled, so I suspect it's related to the
hardware - maybe related to the fact that it is headless. But nothing else has
this problem but ISOLINUX. Is there any way I can absolutely turn VGA totally
off (not counting "console 0" which I've already done)? Maybe by
a code hack?
I have tried xterm, urxvt, and cygwin terminal emulators.
I have no idea where these escape sequences could be coming from. I've
search and searched and searched everything on the web SYSLINUX related to no
avail. I've looked at the source code. Please help! Thanks.
Here is the configuration file:
serial 0 115200
console 0
default shell
implicit 1
display isolinux.msg
prompt 1
timeout 600
label install
kernel linux
append initrd=initrd ramdisk_size=512000 ramdisk_blocksize=4096 splash=silent
quiet preloadlog=/dev/null showopts console=ttyS0,115200n8
label shell
kernel linux
append initrd=initrd ramdisk_size=512000 ramdisk_blocksize=4096 splash=silent
quiet preloadlog=/dev/null noinstall showopts console=ttyS0,115200n8
On 08/08/2014 10:52 AM, Eric Ewanco wrote:> > This is an example of what I see: > > ISOLINUX2;10H6.022;16HEHDD2;21HCopy > ISOLINUX 6.02 Copyright (C) 1994-2013 H. Peter Anvin et al >This is due to you having serial emulation enabled in your BIOS, and a terminal emulator which doesn't support standard escape sequences. "Console 0" should have eliminated that output after the banner line, that is the confusing bit. -hpa
On Aug 8, 2014 1:57 PM, "Eric Ewanco" <Eric.Ewanco at genband.com> wrote:> > We have a system that is designed with no VGA port, graphics card, orkeyboard, only a serial console. We're trying to boot a Linux via ISOLINUX. The problem is that when ISOLINUX comes up, the screen is usually garbled. Not always; sometimes it's intact, sometimes it's completely blank. When it is garbled, it is NOT the garbled text of a wrong baud rate. Rather, it looks like someone is interleaving cursor escape sequences into the text; there are lots of [ and [H and semicolons and digits and so forth. This almost sounds like dropped symbols.> We were using 4.04 but I downloaded and built 6.02 just to check to seeif it had been fixed, and it was not. Curiously, when I misconfigured the image (I put syslinux.c32 into the wrong directory), the brief message I got (the copyright banner and the error message to press a key to retry) worked just fine on several tries. Once I fixed that it broke again. It comes precompiled. Try using it without running make at all. Also try 3.86.> This is an example of what I see: > > ISOLINUX2;10H6.022;16HEHDD2;21HCopy > ISOLINUX 6.02 Copyright (C) 1994-2013 H. Peter Anvin et al > > > Fourscore and twenty years ago, our forefathers brought forth > on thiscontinent a new nation -- conceived in liberty and>dedicated to the proposition that all men are created equal.> Now we are engagedin a great Civil War, testing whether this>nation, or any nation, can long endure. Wrie agre hmet tona [grea2t;>b3attlef1iHeld( of Cthat war. We) hve come [to2 dedi;c3ate5 a portioHn of1> that fi9el9d, 4as a f-inal2 r0e1sting3 la[c2e; for4 th5osHewhoH her.e ave>thei[r li2ves ;t4h8at HthaPt naetitoen mirghtl[ive2.; It 5is4 altogether> fHitAting and propnerv that we shouildndo thi.>[2;6boot: 0Het2;63Hal3;1Hboot:3;7H> > Here much of the text merely disappears at the end. (I have no idea whythere are no carriage returns - I even added them in and verified it and it still omits them. A Unix-format file I've used in the past works fine in this regard.) Often it's more corrupted, though, sometimes totally unreadable.> > Here is what it does when I press ^V at the boot: prompt: > > boot: > ?25l222;16HEHDDo.t0:Copyrightg(C)11994-2013-H.1PeterSAnvintetralAnvinUetX al> boot: > [16L[INU2X 46.02 E;HD1D CoHpI(C)i1994-2013)H.NPeter2Anvin.et[alte4r;1A0nHvi6n .e0t2 al> boot: > > The BIOS works fine. Once Linux is booted, it works fine. GRUB worksfine (that's installed at a later stage). Only ISOLINUX has problems.> > I tried changing the baud rate from 115200 to 9600 to no avail. > > If I boot an ISOLINUX image that works on another piece of hardware onthis piece of hardware, it is also garbled, so I suspect it's related to the hardware - maybe related to the fact that it is headless. But nothing else has this problem but ISOLINUX. Is there any way I can absolutely turn VGA totally off (not counting "console 0" which I've already done)? Maybe by a code hack?> > I have tried xterm, urxvt, and cygwin terminal emulators.Tried ANSI versus VT100 or to enable escape sequence interpretation?> I have no idea where these escape sequences could be coming from. I'vesearch and searched and searched everything on the web SYSLINUX related to no avail. I've looked at the source code. Please help! Thanks.> > Here is the configuration file: > > serial 0 115200 > console 0 > default shell > implicit 1 > display isolinux.msg > prompt 1 > timeout 600 > label install > kernel linux > append initrd=initrd ramdisk_size=512000 ramdisk_blocksize=4096splash=silent> quiet preloadlog=/dev/null showopts console=ttyS0,115200n8 > label shell > kernel linux > append initrd=initrd ramdisk_size=512000 ramdisk_blocksize=4096splash=silent> quiet preloadlog=/dev/null noinstall showopts console=ttyS0,115200n8Config looks good. Considered "SERIAL 0 115200 0x008" our "NOHALT 1"? --Gene