Re: [coreboot] GRUB2 is too big as a payload in ThinkPad X201

[Paul Menzel]

      Dear Iru,


welcome to coreboot!


Am Donnerstag, den 26.03.2015, 09:33 +0800 schrieb Iru Cai:
  I tried to use GRUB2 as a payload when building
coreboot for ThinkPad X201,
 but it's too big to fit into the rom. The GRUB2 coreboot image without
 modules is 2.8M and >800K after compressing, it's still too big.
building GRUB directly, I get a different result.

        $ git describe
        grub-2.02-beta2-372-g5974d4b
        $ ./autogen.sh
        $ ./configure --with-platform=coreboot --enable-boot-time --enable-cache-stats
        $ make
        $ edit Makefile

Now adapt the rule `default_payload.elf`.

        default_payload.elf: grub-mkstandalone grub-mkimage
        	pkgdatadir=. ./grub-mkstandalone --grub-mkimage=./grub-mkimage -O i386-coreboot
-o $@ --modules='ahci pata ehci uhci ohci usb_keyboard usbms part_msdos xfs ext2 fat
at_keyboard part_gpt usbserial_usbdebug cbfs' --install-modules='ls linux search
configfile normal cbtime cbls memrw iorw minicmd lsmmap lspci halt reboot hexdump pcidump
regexp setpci lsacpi chain test serial multiboot cbmemc linux16 gzio echo help'
--fonts= --themes= --locales= -d grub-core/ /boot/grub/grub.cfg=$(srcdir)/coreboot.cfg

Remove the modules you don’t need. With *my* ASRock E350M1 setup, I
don’t need `pata`, `usbms`, `xfs`, `fat`, `at_keyboard`, `part_gpt` and
`usbserial_usbdebug`. I then add `boottime` and `cacheinfo`.

        $ make default_payload.elf

The file is now 578K big and in CBFS the compressed size is a little
over 200 KB.

        $ build/cbfstool build/coreboot.rom print
        […]
                fallback/payload               0x5c400    payload
                205851
        […]

[…]


Thanks,

Paul


PS: I’d be great if you could just send plain text messages with no HTML
parts to mailing lists.

GRUB2 is too big as a payload in ThinkPad X201

[Alexandru Gagniuc]

      On Thursday, March 26, 2015 07:53:04 AM Paul Menzel wrote:
  The file is now 578K big and in CBFS the compressed
size is a little
 over 200 KB.
I never understood how grub2 can do less than seabios but be much larger. OK, 
you caught me! grub2 can read files off a disk.

Alex

GRUB2 is too big as a payload in ThinkPad X201

[Berth-Olof Bergman]

      Personally I don’t understand why boot loaders insist on writing the code the way they do.
There is BIOS services for boot device I/O, serial port debug and putting payloads
anywhere in memory. I think a boot loader will suffice running in 16-bit real mode or
unreal mode (16-bit code, 32-bit data) and using the BIOS APIs to communicate with the
hardware. It will always be compatible and a lot faster. I think most boot loaders are
overly bloated.

  26 mar 2015 kl. 19:54 skrev Alexandru Gagniuc via
coreboot <coreboot(a)coreboot.org>rg>:
 
 On Thursday, March 26, 2015 07:53:04 AM Paul Menzel wrote:
  The file is now 578K big and in CBFS the
compressed size is a little
 over 200 KB.
 I never understood how grub2 can do less than seabios but be much larger. OK, 
 you caught me! grub2 can read files off a disk.
 
 Alex
 
 -- 
 coreboot mailing list: coreboot(a)coreboot.org
 http://www.coreboot.org/mailman/listinfo/coreboot

GRUB2 is too big as a payload in ThinkPad X201

[Peter Stuge]

      Berth-Olof Bergman wrote:
  Personally I don’t understand why boot loaders insist
on writing
 the code the way they do. There is BIOS services
I'm afraid you've missed the whole point of coreboot; to break away
from the extremely limited and technically nonsensical legacy BIOS.


//Peter

GRUB2 is too big as a payload in ThinkPad X201

[Alexandru Gagniuc]

      On Friday, March 27, 2015 11:49:54 AM Berth-Olof Bergman wrote:
  Personally I don’t understand why boot loaders insist
on writing the code
 the way they do. There is BIOS services for boot device I/O, serial port
 debug and putting payloads anywhere in memory. I think a boot loader will
 suffice running in 16-bit real mode or unreal mode (16-bit code, 32-bit
 data) and using the BIOS APIs to communicate with the hardware. It will
 always be compatible and a lot faster. I think most boot loaders are overly
 bloated.
And you'd rather bloat the hardware init code instead? The code for those 
services has to reside _somewhere_.

Guess what! SeaBIOS does all that, and it's paper thin. I wish the GRUB guys 
would figure out the bloat. They probably already did, but didn't document it.

Alex

GRUB2 is too big as a payload in ThinkPad X201

[The Gluglug]

      -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



On 30/03/15 12:04, Alexandru Gagniuc via coreboot wrote:
  They probably already did, but didn't document it.
That sounds about right.
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GRUB 2 is a great payload! (was: GRUB2 is too big as a payload in ThinkPad X201)

[Paul Menzel]

      Dear Alexandru,


Am Donnerstag, den 26.03.2015, 11:54 -0700 schrieb Alexandru Gagniuc:
  On Thursday, March 26, 2015 07:53:04 AM Paul Menzel
wrote:
  The file is now 578K big and in CBFS the
compressed size is a little
 over 200 KB.
 I never understood how grub2 can do less than seabios but be much larger. OK, 
 you caught me! grub2 can read files off a disk.
On most installations I know, „all that SeaBIOS does“ is to run Option
ROMs (mostly only Video BIOS’s) and then to execute GRUB from somewhere.
Users with a modern operating system don’t need the BIOS legacy stuff it
sets up.

So I don’t know where this GRUB bashing is coming from, but in my
experience GRUB is a great payload and it makes sense to load it
directly and let coreboot run the VGA Option ROM/Video BIOS.

In my tests on with the ASRock E350M1, even though the GRUB payload is
bigger in size, there is no noticeable speed difference between using
SeaBIOS or GRUB as a payload.

Some more great features and modules:

1. GRUB gives you a command line interface. The time-out can be set to 0.
2. Debugging with lspci, lsacpi, setpci, …
3. Instrumentation with boottime, cacheinfo, …
4. Show CBMEM console with `cbmemc`.
5. Show CBMEM time stamps with `coreboot_boottime`.
6. Support for coreboot systems with native graphics support.

And the cherry on top: If you don’t need a functionality, for example in
production after development, most of it is provided through modules. So
customize your build and don’t include the unneeded modules to make the
image even smaller to scrape off the last milliseconds of your boot
time.

So big thank you to the GRUB developers, especially Vladimir
φ-coder/phcoder for their work and support.

Also big thank you to all other payload developers. Especially to Kevin
for working on SeaBIOS, which fulfills its use case awesomely well, and
for being always responsive and helpful.


Thanks,

Paul

GRUB 2 is a great payload! (was: GRUB2 is too big as a payload in ThinkPad X201)

[Charles Devereaux]

      Hello

On Mon, Apr 6, 2015 at 4:46 PM, Paul Menzel <
paulepanter(a)users.sourceforge.net&gt; wrote:

  Some more great features and modules:

 1. GRUB gives you a command line interface. The time-out can be set to 0.
 2. Debugging with lspci, lsacpi, setpci, …
 3. Instrumentation with boottime, cacheinfo, …
 4. Show CBMEM console with `cbmemc`.
 5. Show CBMEM time stamps with `coreboot_boottime`.
 6. Support for coreboot systems with native graphics support.
To which I would add:
 7. support for a menu, so that your most frequent options can be selected
with a few keys
 8. support for LUKS, so that you can protect your /boot

The only missing functionality is the lack of support for silent boot (set
timeout_style=hidden) to show the boot menu upon a keypress.

With native graphics support, I would love to be able to start FreeDOS, or
memtest with screen output. Someday with SeaBIOS maybe. In any case, grub2
is a must.

Charles

GRUB 2 is a great payload! (was: GRUB2 is too big as a payload in ThinkPad X201)

[Alexandru Gagniuc]

      On Monday, April 06, 2015 10:46:32 PM Paul Menzel wrote:
  Dear Alexandru,
 
 Am Donnerstag, den 26.03.2015, 11:54 -0700 schrieb Alexandru Gagniuc:
  On Thursday, March 26, 2015 07:53:04 AM Paul
Menzel wrote:
  The file is now 578K big and in CBFS the
compressed size is a little
 over 200 KB.
 
 I never understood how grub2 can do less than seabios but be much larger.
 OK, you caught me! grub2 can read files off a disk.
 
 
 So I don’t know where this GRUB bashing
Bashing? For noticing that GRUB is larger
than SeaBIOS?

  Some more great features and modules:
 
 1. GRUB gives you a command line interface. The time-out can be set to 0.
 2. Debugging with lspci, lsacpi, setpci, …
 3. Instrumentation with boottime, cacheinfo, …
 4. Show CBMEM console with `cbmemc`.
 5. Show CBMEM time stamps with `coreboot_boottime`.
 6. Support for coreboot systems with native graphics support.
I know very well what GRUB2 is capable of.

  And the cherry on top: If you don’t need a
functionality, for example in
 production after development, most of it is provided through modules.
Sure. You can trim off some of the fat. If you know how to trim enough so that 
it's comparable in size to SeaBIOS, please let me know.

  So big thank you to the GRUB developers, especially
Vladimir
 φ-coder/phcoder for their work and support.
Thanks, Vladimir!
 
  Also big thank you to all other payload developers.
Especially to Kevin
 for working on SeaBIOS, which fulfills its use case awesomely well, and
 for being always responsive and helpful.
 
 
 Thanks,
Alex

GRUB 2 is a great payload!

[Paul Menzel]

      Dear Alexandru,


Am Montag, den 06.04.2015, 14:07 -0700 schrieb Alexandru Gagniuc:
  On Monday, April 06, 2015 10:46:32 PM Paul Menzel
wrote:
  Am Donnerstag,
den 26.03.2015, 11:54 -0700 schrieb Alexandru Gagniuc:
  On Thursday, March 26, 2015 07:53:04 AM Paul
Menzel wrote:
  The file is now 578K big and in CBFS the
compressed size is a little
 over 200 KB.
 
 I never understood how grub2 can do less than seabios but be much larger.
 OK, you caught me! grub2 can read files off a disk.
 So I don’t know where this GRUB bashing
 Bashing? For noticing that GRUB is larger
than SeaBIOS?
Then I misunderstood/misinterpreted: “… how grub2 can do less than
seabios …”.

  Some more
great features and modules:
 
 1. GRUB gives you a command line interface. The time-out can be set to 0.
 2. Debugging with lspci, lsacpi, setpci, …
 3. Instrumentation with boottime, cacheinfo, …
 4. Show CBMEM console with `cbmemc`.
 5. Show CBMEM time stamps with `coreboot_boottime`.
 6. Support for coreboot systems with native graphics support.
 
 I know very well what GRUB2 is capable of.
 
  And the cherry on top: If you don’t need a
functionality, for example in
 production after development, most of it is provided through modules.
 
 Sure. You can trim off some of the fat. If you know how to trim enough so that 
 it's comparable in size to SeaBIOS, please let me know.
I will.

Please let me understand your point better. I don’t see, why that size
difference is a problem?

Do you have a system where a 200 kB GRUB payload doesn’t fit? Did you
measure any speed differences? (But as stated, SeaBIOS loads/starts GRUB
most of the time from the a storage medium.)


Thanks,

Paul

GRUB 2 is a great payload!

[Alexandru Gagniuc]

      On Monday, April 06, 2015 11:22:18 PM Paul Menzel wrote:
  Dear Alexandru,
 
 Am Montag, den 06.04.2015, 14:07 -0700 schrieb Alexandru Gagniuc:
  On Monday, April 06, 2015 10:46:32 PM Paul Menzel
wrote:
  Am Donnerstag, den 26.03.2015, 11:54 -0700
schrieb Alexandru Gagniuc:
  On Thursday, March 26, 2015 07:53:04 AM Paul
Menzel wrote:
 > The file is now 578K big and in CBFS the compressed size is a little
 > over 200 KB.
 
 I never understood how grub2 can do less than seabios but be much
 larger.
 OK, you caught me! grub2 can read files off a disk.
 
 So I don’t know where this GRUB bashing
 
 Bashing? For noticing that GRUB is larger than SeaBIOS?
 
 Then I misunderstood/misinterpreted: “… how grub2 can do less than
 seabios …”.
I meant "how much it actually does", not "how much it is capable of
doing". I 
doubt you boot from USB all day long.

  And the cherry on top: If you don’t need a
functionality, for example in
 production after development, most of it is provided through modules.
 
 Sure. You can trim off some of the fat. If you know how to trim enough so
 that it's comparable in size to SeaBIOS, please let me know.
 
 I will.
I'm not geek enough to build GRUB2. Last time I did it, I was telepathically 
controlled by Vladimir via IRC.

  Please let me understand your point better. I don’t
see, why that size
 difference is a problem?
This shouldn't even be questioned. Smaller is always better. Anyhow, the big 
issue is when you're running normal/fallback.

  Do you have a system where a 200 kB GRUB payload
doesn’t fit?
I've had this issue on many occasions. Since I've gotten rid of MRC.bin on 
butterfly, I've been able to do SeaBIOS/Grub2 fallback/normal. Might need a bit 
of trimming to get to grub2/grub2.

  Did you
 measure any speed differences? (But as stated, SeaBIOS loads/starts GRUB
 most of the time from the a storage medium.)
SeaBIOS, GRUB, or SeaBIOS + GRUB has always been fast for me. It's software 
that just works 99.99% of the time.

  
 Thanks,
Alex

GRUB 2 is a great payload!

[Gerd Hoffmann]

        Hi,

  Please let me
understand your point better. I don’t see, why that size
 difference is a problem?
 This shouldn't even be questioned. Smaller is always better.
grub is doing stuff seabios doesn't.  For example parsing file systems.
The code for that needs to go somewhere.  So you are kind of comparing
apples to oranges here ...

cheers,
  Gerd

Reduce size of GRUB 2 payload (was: GRUB 2 is a great payload!)

[Paul Menzel]

      Dear Alexandru,


Am Montag, den 06.04.2015, 23:09 -0700 schrieb Alexandru Gagniuc:
  On Monday, April 06, 2015 11:22:18 PM Paul Menzel
wrote:
  > Am Montag, den 06.04.2015, 14:07 -0700 schrieb
Alexandru Gagniuc:
 > > On Monday, April 06, 2015 10:46:32 PM Paul Menzel wrote:
 > > > Am Donnerstag, den 26.03.2015, 11:54 -0700 schrieb Alexandru Gagniuc:
 > > > > On Thursday, March 26, 2015 07:53:04 AM Paul Menzel wrote:
[…]

  And the cherry
on top: If you don’t need a functionality, for example in
 production after development, most of it is provided through modules.
 
 Sure. You can trim off some of the fat. If you know how to trim enough so
 that it's comparable in size to SeaBIOS, please let me know.
 
 I will.
  
 I'm not geek enough to build GRUB2.
everybody knows, you are capable enough to do it. Otherwise Google would
not be your employer. ;-)

  Last time I did it, I was telepathically controlled by
Vladimir via IRC.
Well, it’s now integrated into coreboot’s and GRUB’s build system.

In coreboot, just select GRUB as the payload in Kconfig. You can also do
the step manually.

In GRUB, just do (in a Git checkout) to get the payload
`default_payload.elf`.

        $ ./autogen.sh
        $ ./configure --with-platform=coreboot
        $ make -j
        $ make default_payload.elf
        pkgdatadir=. ./grub-mkstandalone --grub-mkimage=./grub-mkimage -O i386-coreboot -o
default_payload.elf --modules='ahci pata ehci uhci ohci usb_keyboard usbms part_msdos
xfs ext2 fat at_keyboard part_gpt usbserial_usbdebug cbfs' --install-modules='ls
linux search configfile normal cbtime cbls memrw iorw minicmd lsmmap lspci halt reboot
hexdump pcidump regexp setpci lsacpi chain test serial multiboot cbmemc linux16 gzio echo
help' --fonts= --themes= --locales= -d grub-core/ /boot/grub/grub.cfg=./coreboot.cfg
        $ du -sh default_payload.elf
        720K	default_payload.elf

If you don’t want the default modules, adapt `Makefile` and edit the
target `default_payload`.

  Please let me
understand your point better. I don’t see, why that size
 difference is a problem?
  
 This shouldn't even be questioned. Smaller is always better. Anyhow, the big 
 issue is when you're running normal/fallback.
 
  Do you have a system where a 200 kB GRUB payload
doesn’t fit?
 
 I've had this issue on many occasions. Since I've gotten rid of MRC.bin on 
 butterfly, I've been able to do SeaBIOS/Grub2 fallback/normal. Might need a bit 
 of trimming to get to grub2/grub2.
Hmm, I don’t see how it can be a problem with flash ROM sizes of 4 MB.
But anyway, let’s remove most of the modules and only include cbfs and
`chain`. You need to tune your `grub.cfg` so it works. (Note, that I did
not test this yet.)

        $ make default_payload.elf
        pkgdatadir=. ./grub-mkstandalone --grub-mkimage=./grub-mkimage -O i386-coreboot -o
default_payload.elf --modules='cbfs' --install-modules='chain' --fonts=
--themes= --locales= -d grub-core/ /boot/grub/grub.cfg=./coreboot.cfg
        $ du -sh default_payload.elf
        168K	default_payload.elf
        $ xz default_payload.elf && du -sh default_payload.elf.xz
        64K	default_payload.elf.xz
        $ du -sh /seabios/out/bios.bin.elf
        72K	/home/paul/src/seabios/out/bios.bin.elf

So it’s well under a 100 KB.


Thanks,

Paul

GRUB 2 is a great payload!

[The Gluglug]

      -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1



  I'm not geek enough to build GRUB2. Last time I
did it, I was
 telepathically controlled by Vladimir via IRC.
Use the libreboot build system, it basically automates everything.
Just use GRUB from it:

./download all
install GRUB build dependencies
./build module grub

Then cd to resources/utilities/grub-assemble/

There are files in there with the list of modules used.
Then run the "gen.sh" script in there to generate a grub.elf file.
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GRUB 2 is a great payload!

[The Gluglug]

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Hash: SHA1

(also, that puts a grub.elf in memdisk inside the grub.elf, which just
jumps to grub.elf in CBFS)

So just put a grub.elf in cbfs root. ROM images in libreboot have a
grub.cfg that you can use as a template (just extract the grub.cfg)

Another nice thing, it puts lots of keyboard layouts in the grub.elf
(it even has Dvorak support)

On 13/04/15 00:23, The Gluglug wrote:
  
 
  I'm not geek enough to build GRUB2. Last time
I did it, I was 
 telepathically controlled by Vladimir via IRC.
 
 
 Use the libreboot build system, it basically automates everything. 
 Just use GRUB from it:
 
 ./download all install GRUB build dependencies ./build module grub
 
 Then cd to resources/utilities/grub-assemble/
 
 There are files in there with the list of modules used. Then run
 the "gen.sh" script in there to generate a grub.elf file.
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GRUB 2 is a great payload!

[The Gluglug]

      -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

uh.... I mean grub.cfg in memdisk inside grub.elf, which loads
grub.cfg from CBFS

"grub.elf in cbfs" replace with "grub.cfg in cbfs" etc
it's late

On 13/04/15 00:27, The Gluglug wrote:
  (also, that puts a grub.elf in memdisk inside the
grub.elf, which
 just jumps to grub.elf in CBFS)
 
 So just put a grub.elf in cbfs root. ROM images in libreboot have
 a grub.cfg that you can use as a template (just extract the
 grub.cfg)
 
 Another nice thing, it puts lots of keyboard layouts in the
 grub.elf (it even has Dvorak support)
 
 On 13/04/15 00:23, The Gluglug wrote:
 
 
 > I'm not geek enough to build GRUB2. Last
time I did it, I was 
> telepathically controlled by Vladimir via IRC.
 
 
  Use the libreboot build system, it basically
automates
 everything. Just use GRUB from it:
 
  ./download all install GRUB build dependencies
./build module
 grub
 
  Then cd to resources/utilities/grub-assemble/
 
  There are files in there with the list of modules
used. Then run 
 the "gen.sh" script in there to generate a grub.elf file.
 
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GRUB 2 isn't a great payload at all

[Peter Stuge]

      FWIW, I dislike GRUB for several reasons; it does far too much to be
an improvement over a minimal payload and it does far too little te
be an improvement over a Linux payload.

It duplicates lots of work already exists in other places and it has
probably also duplicated some of the bugs.

Not to mention the reliability problems I have had with GRUB a long
time ago. A bootloader which spontaneously stops booting my system
does not get a second chance. Sorry, that's just a waste of time.

It could be argued that GRUB2 is not GRUB, but I don't think GRUB2
is an improvement.


Paul Menzel wrote:
  in my experience GRUB is a great payload and it makes
sense to load
 it directly and let coreboot run the VGA Option ROM/Video BIOS.
I disagree strongly that it makes sense. coreboot doesn't provide a
BIOS environment and is thus not suitable for option ROM execution.
When it happens to work that is clearly a corner case.

Recommending a corner case (requiring discovery of details of each
option ROM) for the general case just is not good advice.


//Peter

GRUB 2 isn't a great payload at all

[Paul Menzel]

      Am Samstag, den 11.04.2015, 18:29 +0200 schrieb Peter Stuge:
  FWIW, I dislike GRUB for several reasons; it does far
too much to be
 an improvement over a minimal payload
Which payloads do you have in mind?

  and it does far too little to be an improvement over a
Linux payload.
I guess that depends on your needs and the hardware.

1. Is there enough room for the Linux payload?
2. The Linux kernel has to be updated far more often in my experience
than GRUB. Each Linux kernel upgrade requires manual work.

  It duplicates lots of work already exists in other
places and it has
 probably also duplicated some of the bugs.
Could you please list those you have experienced as I cannot think of
anything yet?

  Not to mention the reliability problems I have had
with GRUB a long
 time ago. A bootloader which spontaneously stops booting my system
 does not get a second chance. Sorry, that's just a waste of time.
 
 It could be argued that GRUB2 is not GRUB, but I don't think GRUB2
 is an improvement.
A lot has changed! ;-) There is also test suite (`make check`) and I
haven’t had any problems for over three or four years. You should give
it another try.

  Paul Menzel wrote:
  in my experience GRUB is a great payload and it
makes sense to load
 it directly and let coreboot run the VGA Option ROM/Video BIOS.
 
 I disagree strongly that it makes sense. coreboot doesn't provide a
 BIOS environment and is thus not suitable for option ROM execution.
 When it happens to work that is clearly a corner case.
In my experience all VGA Option ROMs which worked in SeaBIOS could also
be successfully run by coreboot as coreboot was doing that for a long
time before SeaBIOS existed.

  Recommending a corner case (requiring discovery of
details of each
 option ROM) for the general case just is not good advice.
Agreed.

One last question, as you wrote above, you prefer a Linux kernel
payload, how do you deal with VGA Option ROMs in that situation? Or do
you only use the Linux kernel payload if coreboot has support for native
graphics initialization for the graphics device?


Thanks,

Paul