Re: Migrations to xorriso

Re: Migrations to xorriso

[Thomas Schmitt]

[-- Attachment #1: Type: text/plain, Size: 820 bytes --]

Hi,

would the following changes be acceptable for
grub-mkrescue ?

- Option  --xorriso=PROGFILE  allows to use a
  particular binary as xorriso program.
  This will avoid the need to install xorriso.
  One can just unpack and build it in some
  directory and use .../xorriso/xorriso
  as binary.

- Option --diet saves about 400 kB of image
  size without losing much benefit.

I attach an untested patch to illustrate the
intended changes.
If ok in principle, then i would do
beautifications and make some tests.

Nevertheless, a GRUB expert should make own
tests afterwards. So maybe Vladimir wants 
to take it just as proposal for an own 
more qualified change.


Have a nice day :)

Thomas

-- 
GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

[-- Attachment #2: grub-mkrescue.in.ts.patch --]
[-- Type: text/x-patch, Size: 1777 bytes --]

--- grub-mkrescue.in	2010-05-18 10:02:06.000000000 +0200
+++ grub-mkrescue.in.ts	2010-05-19 13:53:18.000000000 +0200
@@ -38,6 +38,9 @@ efi32_dir=${libdir}/$(echo ${PACKAGE_TAR
 efi64_dir=${libdir}/$(echo ${PACKAGE_TARNAME} | sed ${transform})/x86_64-efi
 rom_directory=
 
+xorriso=xorriso
+diet=no
+
 # Usage: usage
 # Print the usage.
 usage () {
@@ -50,6 +53,8 @@ Make GRUB rescue image.
   --output=FILE           save output in FILE [required]
   --modules=MODULES       pre-load specified modules MODULES
   --rom-directory=DIR     save rom images in DIR [optional]
+  --xorriso=PROGFILE      use PROGFILE as xorriso program [optional]
+  --diet                  apply size reducing measures [optional]
 
 $0 generates a bootable rescue image with specified source files or directories.
 
@@ -78,6 +83,10 @@ for option in "$@"; do
 	PATH=${override_dir}:$PATH
 	export PATH
 	;;
+    --xorriso=*)
+	xorriso=`echo "${option}/" | sed 's/--xorriso=//'` ;;
+    --diet)
+	diet=yes ;;
     -*)
 	echo "Unrecognized option \`$option'" 1>&2
 	usage
@@ -254,7 +263,14 @@ if [ -e "${iso9660_dir}/boot/coreboot.el
 fi
 
 # build iso image
-xorriso -pathspecs on -as mkisofs ${grub_mkisofs_arguments} --protective-msdos-label -o ${output_image} -r ${iso9660_dir} ${source}
+if [ "${diet}" = yes ]; then
+    if [ -e "${output_image}" ]; then
+        rm "${output_image}" || exit 1
+    fi
+    "${xorriso}" -report_about HINT -as mkisofs -graft-points -no-pad ${grub_mkisofs_arguments} --protective-msdos-label -r ${iso9660_dir} ${source} | cat >"${output_image}"
+else
+    "${xorriso}" -report_about HINT -as mkisofs -graft-points ${grub_mkisofs_arguments} --protective-msdos-label -o "${output_image}" -r ${iso9660_dir} ${source}
+fi
 rm -rf ${iso9660_dir}
 
 rm -f ${embed_img}

Re: Migrations to xorriso

[Colin Watson]

On Wed, May 19, 2010 at 02:01:50PM +0200, Thomas Schmitt wrote:
> would the following changes be acceptable for
> grub-mkrescue ?
> 
> - Option  --xorriso=PROGFILE  allows to use a
>   particular binary as xorriso program.
>   This will avoid the need to install xorriso.
>   One can just unpack and build it in some
>   directory and use .../xorriso/xorriso
>   as binary.

This is in line with other options already in GRUB utility scripts, so
seems sensible.

> - Option --diet saves about 400 kB of image
>   size without losing much benefit.

I don't have much of an opinion on this; but if it doesn't lose much,
why would it not be the default?  Or, put another way, why would
somebody want to turn this option off?

> +    "${xorriso}" -report_about HINT -as mkisofs -graft-points -no-pad ${grub_mkisofs_arguments} --protective-msdos-label -r ${iso9660_dir} ${source} | cat >"${output_image}"

Useless use of cat.

-- 
Colin Watson                                       [cjwatson@ubuntu.com]

Re: Migrations to xorriso

[Thomas Schmitt]

Hi,

> > - Option --diet saves about 400 kB of image
> >   size without losing much benefit.
> If it doesn't lose much,
> why would it not be the default?

Maybe one should revert the default and offer
an option
  --multi-session-toc
instead ?


>  Or, put another way, why would
> somebody want to turn this option off?

I could want a bootable multi-session backup
on USB stick with the opportunity to mount the
backup state of two weeks ago.
For that i'd start with a rescue system created
by grub-mkrescue, add my base backup as second
session and daily updates as further sessions.


The extra 64 kB to 126 kB make sure that the
older sessions of a multi-session ISO image can
be detected and mounted. Useful with incremental
backups on regular files, USB sticks, DVD+RW or
BD-RE media.
But not so much of interest with a single session
rescue image.

Without this extra space one can still add new
sessions but will always see the youngest one as
the only session of the image. (growisofs does
it that way.)
If the first session ends up on sequential media
(CD-R[W], DVD-R, DVD+R, BD-R) then further
multi-session will be managed by the drive
anyway.


> Useless use of cat.

Not in this case. xorriso calls fstat(2) to
determine the semantics of the given output file.
Option -o "${output_image}" or a redirection
by >"${output_image}" would both reveil type
S_IFREG.
But for the diet case i want S_ISCHR or S_IFIFO
so that the output "media" appears as sequential
rather than as overwriteable.


Have a nice day :)

Thomas

Re: Migrations to xorriso

[Vladimir 'φ-coder/phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 2250 bytes --]

Thomas Schmitt wrote:
> Hi,
>
>   
>>> - Option --diet saves about 400 kB of image
>>>   size without losing much benefit.
>>>       
>> If it doesn't lose much,
>> why would it not be the default?
>>     
>
> Maybe one should revert the default and offer
> an option
>   --multi-session-toc
> instead ?
>
>   
As said in another mail size saving matters only for floppy. Otherwise I
prefer the most standard way possible
>   
>>  Or, put another way, why would
>> somebody want to turn this option off?
>>     
>
> I could want a bootable multi-session backup
> on USB stick with the opportunity to mount the
> backup state of two weeks ago.
> For that i'd start with a rescue system created
> by grub-mkrescue, add my base backup as second
> session and daily updates as further sessions.
>
>
> The extra 64 kB to 126 kB make sure that the
> older sessions of a multi-session ISO image can
> be detected and mounted. Useful with incremental
> backups on regular files, USB sticks, DVD+RW or
> BD-RE media.
> But not so much of interest with a single session
> rescue image.
>
> Without this extra space one can still add new
> sessions but will always see the youngest one as
> the only session of the image. (growisofs does
> it that way.)
> If the first session ends up on sequential media
> (CD-R[W], DVD-R, DVD+R, BD-R) then further
> multi-session will be managed by the drive
> anyway.
>
>
>   
Puppy linux does that. I think it's sensible. However it's up to
distributors and individual users whether to make advantage of such
features.
>> Useless use of cat.
>>     
>
> Not in this case. xorriso calls fstat(2) to
> determine the semantics of the given output file.
> Option -o "${output_image}" or a redirection
> by >"${output_image}" would both reveil type
> S_IFREG.
> But for the diet case i want S_ISCHR or S_IFIFO
> so that the output "media" appears as sequential
> rather than as overwriteable.
>
>
> Have a nice day :)
>
> Thomas
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 293 bytes --]

Re: Migrations to xorriso

[Isaac Dupree]

On 05/19/10 08:13, Colin Watson wrote:
> On Wed, May 19, 2010 at 02:01:50PM +0200, Thomas Schmitt wrote:
>> - Option --diet saves about 400 kB of image
>>    size without losing much benefit.
>
> I don't have much of an opinion on this; but if it doesn't lose much,
> why would it not be the default?  Or, put another way, why would
> somebody want to turn this option off?

What size range are the whole images?  For example, saving 400 kB off of 
500 MB seems less useful than saving 400 kB off of 2 MB.

(Also I guess no one compresses whole ISOs so it needn't be asked how 
well the extra kilobytes compress.)

-Isaac

Re: Migrations to xorriso

[Thomas Schmitt]

Hi,

Isaac Dupree wrote:
> What size range are the whole images? 

The minimum output of grub-mkrescue 1.98 with
xorriso is 1544192 bytes.
grub-mkisofs: 1550336
genisoimage:  1859584 (-307200 with -no-pad)

One may add lots of other files, of course.


> Also I guess no one compresses whole ISOs

It makes few sense to compress the ISO as a
whole. But one could compress some files in it.

One could implement a reader for H. Peter Anvin's
zisofs format in GRUB's ISO 9660 reader - if not
present already.
zisofs is a transparent content compression of
single files. A reader is implemented in the
Linux kernel. See macro CONFIG_ZISOFS in
fs/isofs/*.[ch].
An authorised description is given in
doc/zisofs_format.txt of xorriso resp. in
  http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/annotate/head:/doc/zisofs_format.txt
The ISO 9660 directory tree stays uncompressed.
Compressed and uncompressed files can be mixed.

xorriso can produce zisofs compressed data files
on the fly (needs zlib).
A grub-mkrescue 1.98 image with all files
compressed has 884736 bytes. But one would have
to leave those files uncompressed which are
needed for reading ISO 9660 and zisofs
compression.

Have a nice day :)

Thomas
 

Re: Migrations to xorriso

[Vladimir 'φ-coder/phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 1932 bytes --]

Thomas Schmitt wrote:
> Hi,
>
> Isaac Dupree wrote:
>   
>> What size range are the whole images? 
>>     
>
> The minimum output of grub-mkrescue 1.98 with
> xorriso is 1544192 bytes.
> grub-mkisofs: 1550336
> genisoimage:  1859584 (-307200 with -no-pad)
>
> One may add lots of other files, of course.
>
>
>   
>> Also I guess no one compresses whole ISOs
>>     
>
> It makes few sense to compress the ISO as a
> whole. But one could compress some files in it.
>
> One could implement a reader for H. Peter Anvin's
> zisofs format in GRUB's ISO 9660 reader - if not
> present already.
> zisofs is a transparent content compression of
> single files. A reader is implemented in the
> Linux kernel. See macro CONFIG_ZISOFS in
> fs/isofs/*.[ch].
> An authorised description is given in
> doc/zisofs_format.txt of xorriso resp. in
>   http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/annotate/head:/doc/zisofs_format.txt
> The ISO 9660 directory tree stays uncompressed.
> Compressed and uncompressed files can be mixed.
>
> xorriso can produce zisofs compressed data files
> on the fly (needs zlib).
> A grub-mkrescue 1.98 image with all files
> compressed has 884736 bytes. But one would have
> to leave those files uncompressed which are
> needed for reading ISO 9660 and zisofs
> compression.
>
>   
I'm not sure that zisofs is useful for grub. We already have support for
.gz files. xz support is coming. Compressing explicitly we would avoid
to accidently compressing files we need uncompressed. Also we're more
fs-independent.
Implementing zisofs reader may have some value but isn't a priority.
> Have a nice day :)
>
> Thomas
>  
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 293 bytes --]

Re: Migrations to xorriso

[Seth Goldberg]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 2207 bytes --]


Quoting Vladimir 'φ-coder/phcoder' Serbinenko, who wrote the following on...:

> Thomas Schmitt wrote:
>> Hi,
>>
>> Isaac Dupree wrote:
>>
>>> What size range are the whole images?
>>>
>>
>> The minimum output of grub-mkrescue 1.98 with
>> xorriso is 1544192 bytes.
>> grub-mkisofs: 1550336
>> genisoimage:  1859584 (-307200 with -no-pad)
>>
>> One may add lots of other files, of course.
>>
>>
>>
>>> Also I guess no one compresses whole ISOs
>>>
>>
>> It makes few sense to compress the ISO as a
>> whole. But one could compress some files in it.
>>
>> One could implement a reader for H. Peter Anvin's
>> zisofs format in GRUB's ISO 9660 reader - if not
>> present already.
>> zisofs is a transparent content compression of
>> single files. A reader is implemented in the
>> Linux kernel. See macro CONFIG_ZISOFS in
>> fs/isofs/*.[ch].
>> An authorised description is given in
>> doc/zisofs_format.txt of xorriso resp. in
>>   http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/annotate/head:/doc/zisofs_format.txt
>> The ISO 9660 directory tree stays uncompressed.
>> Compressed and uncompressed files can be mixed.
>>
>> xorriso can produce zisofs compressed data files
>> on the fly (needs zlib).
>> A grub-mkrescue 1.98 image with all files
>> compressed has 884736 bytes. But one would have
>> to leave those files uncompressed which are
>> needed for reading ISO 9660 and zisofs
>> compression.
>>
>>
> I'm not sure that zisofs is useful for grub. We already have support for
> .gz files. xz support is coming. Compressing explicitly we would avoid
> to accidently compressing files we need uncompressed. Also we're more
> fs-independent.
> Implementing zisofs reader may have some value but isn't a priority.

  For the record, Solaris uses a ISO9660 filesystem image with individual 
compressed files, but this is mainly useful for being able to have a boot 
archive that grub2 does not have to completely decompress before loading 
into memory (so we get the benefit of a nearly-compressed filesystem image) 
without the overhead (taking the overhead on read operations).  The value to 
grub2, though, is unknown.

  --S

Re: Migrations to xorriso

[Vladimir 'φ-coder/phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 1672 bytes --]

Thomas Schmitt wrote:
> Hi,
>
> would the following changes be acceptable for
> grub-mkrescue ?
>
> - Option  --xorriso=PROGFILE  allows to use a
>   particular binary as xorriso program.
>   This will avoid the need to install xorriso.
>   One can just unpack and build it in some
>   directory and use .../xorriso/xorriso
>   as binary.
>
>   
This can go in. I'll commit it when I have time.

I'm thinking to allow passing arbitrary options to xorriso by just
putting it on command line.
Do you recommend to switching to native xorriso interface? It would
allow to burn disk from grub-mkisofs by passing recording options to
xorriso.
> - Option --diet saves about 400 kB of image
>   size without losing much benefit.
>
> I attach an untested patch to illustrate the
> intended changes.
> If ok in principle, then i would do
> beautifications and make some tests.
>
> Nevertheless, a GRUB expert should make own
> tests afterwards. So maybe Vladimir wants 
> to take it just as proposal for an own 
> more qualified change.
>
>   
This size saving matters only for floppies. Perhaps we should add an
option --pcfloppy which will additionally disable all other platforms.
Also I find the way of configuring with "| cat >" quite ugly. Is there a
reason not to have an option for this behaviour?
> Have a nice day :)
>
> Thomas
>
>   
> ------------------------------------------------------------------------
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 293 bytes --]

Re: Migrations to xorriso

[Thomas Schmitt]

[-- Attachment #1: Type: text/plain, Size: 1554 bytes --]

Hi,

attached is an updated patch to summarize my
current proposal for grub-mkrescue. 

My reply to mails of Vladimir and Seth seems
still stuck in eggs.gnu.org. (At least that
was the culprit last time.)

The current proposal follows Vladimir's idea:
> I'm thinking to allow passing arbitrary options to xorriso by just
> putting it on command line.

It would give the user control over option
-no-pad (saves 300 kB) and allow to switch from
mkisofs emulation to the native xorriso command
set.
 

-----------------------------------------------
New ponderings:
-----------------------------------------------

The following statement in the proposed help text
is due to the way how extra arguments are handled
via variable $source:

"Be aware that source paths must be single words.
 Quotation marks will not work."

If grub-mkrescue options would be prescribed to
precede any source paths or xorriso options, then
we could use a while loop, shift and "$@",
rather than a for loop and ${source}.

while test -n "$1"; do
    case "$1" in
    ...
    --modules=*)
        modules=`echo "$1" | sed 's/--modules=//'`
        shift
        ;;
    ...
    *)
        break ;;
    esac
done
...
${xorriso} ... "$@"


This would be safe for nearly all filenames.
(Newlines are still not allowed then.)

Question is whether support for apple-ish file
names is worth a change in the rules for
grub-mkrescue.


Have a nice day :)

Thomas

-- 
GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

[-- Attachment #2: grub-mkrescue.in.ts2.patch --]
[-- Type: text/x-patch, Size: 1923 bytes --]

--- grub-mkrescue.in	2010-05-18 10:02:06.000000000 +0200
+++ grub-mkrescue.in.ts2	2010-05-20 09:34:56.000000000 +0200
@@ -38,6 +38,8 @@ efi32_dir=${libdir}/$(echo ${PACKAGE_TAR
 efi64_dir=${libdir}/$(echo ${PACKAGE_TARNAME} | sed ${transform})/x86_64-efi
 rom_directory=
 
+xorriso=xorriso
+
 # Usage: usage
 # Print the usage.
 usage () {
@@ -50,10 +52,15 @@ Make GRUB rescue image.
   --output=FILE           save output in FILE [required]
   --modules=MODULES       pre-load specified modules MODULES
   --rom-directory=DIR     save rom images in DIR [optional]
+  --xorriso=PROGFILE      use PROGFILE as xorriso program [optional]
 
-$0 generates a bootable rescue image with specified source files or directories.
+$0 generates a bootable rescue image with specified source files, source
+directories, or mkisofs options listed by: xorriso -as mkisofs -help
+Option -- switches to native xorriso command mode.
+Be aware that source paths must be single words. Quotation marks will not work.
 
 Report bugs to <bug-grub@gnu.org>.
+Mail xorriso support requests to <bug-xorriso@gnu.org>.
 EOF
 }
 
@@ -78,11 +85,8 @@ for option in "$@"; do
 	PATH=${override_dir}:$PATH
 	export PATH
 	;;
-    -*)
-	echo "Unrecognized option \`$option'" 1>&2
-	usage
-	exit 1
-	;;
+    --xorriso=*)
+	xorriso=`echo "${option}/" | sed 's/--xorriso=//'` ;;
     *)
 	source="${source} ${option}" ;;
     esac
@@ -254,7 +258,12 @@ if [ -e "${iso9660_dir}/boot/coreboot.el
 fi
 
 # build iso image
-xorriso -pathspecs on -as mkisofs ${grub_mkisofs_arguments} --protective-msdos-label -o ${output_image} -r ${iso9660_dir} ${source}
+"${xorriso}" -report_about HINT -as mkisofs -graft-points \
+             ${grub_mkisofs_arguments} --protective-msdos-label -r \
+             --sort-weight 0 / --sort-weight 1 /boot \
+             -o "${output_image}" \
+             ${iso9660_dir} ${source}
+
 rm -rf ${iso9660_dir}
 
 rm -f ${embed_img}

Migrations to xorriso

[Vladimir 'φ-coder/phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 552 bytes --]

Hello, all. I would like to announce that as discussed before
grub-mkisofs was removed and we switched to xorriso.
In the same time grub-mkrescue is able to handle efi, coreboot and qemu.
In the later 2 cases you need to use a coreboot.elf/qemu.img as coreboot
payload/qemu rom. It can be found either on iso filesystem or in a
directory supplied by --rom-directory option

@Thomas: grub-mkisofs was partially translated. Could you look into
reusing translation strings for xorriso?

-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 293 bytes --]

Re: Migrations to xorriso

[Thomas Schmitt]

Hi,

while my local bzr upgrade problems still persist
i can view grub-mkrescue.in at 
  https://code.launchpad.net/~vcs-imports/grub/grub2-bzr


> xorriso -pathspecs on -as mkisofs

I would make this
  xorriso -report_about HINT -as mkisofs -graft-points

Option -report_about HINT will reduce verbosity
to the level of messages about unusual events
and remedy proposals.

Since xorriso is run in mkisofs emulation, it
seems clearer to use -graft-points rather than
xorriso option -pathspecs.


> -as mkisofs ${grub_mkisofs_arguments} --protective-msdos-label
> -o ${output_image} -r ${iso9660_dir} ${source}

The potential content of ${grub_mkisofs_arguments}
looks good so far.
I assume you have already tested your use cases.


There remain opportunities for result size
reduction:

The result will be up to 426 kB larger than the
one of grub-mkisofs. (Modern mkisofs or
genisoimage would give you 300 kB extra.)

------------------------------------------------

You may add mkisofs option
  -no-pad
to avoid trailing padding of 300 kB which is only
needed if you later burn the image to a CD in
write mode TAO.
Alternatively you could allow option -no-pad in
the option interpreter of grub-mkrescue rather
than issueing:
    -*) 
        echo "Unrecognized option \`$option'" 1>&2

The burn program can eventually add padding.
xorriso -as cdrecord will by default use write
mode SAO if the file size is detectable.

------------------------------------------------

Another 64 to 126 kB can be saved by hiding the
fact that the target is a random access file.
One would replace
    -o ${output_image}
by
    | cat >${output_image}
This deprives the result of the capability to
show on overwriteable media a table-of-content
with older sessions.

------------------------------------------------

In my tests the size reduced result was 4 kB
smaller than the result from grub-mkisofs.


Have a nice day :)

Thomas

Re: Migrations to xorriso

[Thomas Schmitt]

Hi,

i sent this message 4 hours ago but it did
not show up yet. So i send it again on the risk
to produce a duplicate.

------------------------------------------------

While my local bzr upgrade problems still persist
i can view grub-mkrescue.in at 
  https://code.launchpad.net/~vcs-imports/grub/grub2-bzr


> xorriso -pathspecs on -as mkisofs

I would make this
  xorriso -report_about HINT -as mkisofs -graft-points

Option -report_about HINT will reduce verbosity
to the level of messages about unusual events
and remedy proposals.

Since xorriso is run in mkisofs emulation, it
seems clearer to use -graft-points rather than
xorriso option -pathspecs.


> -as mkisofs ${grub_mkisofs_arguments} --protective-msdos-label
> -o ${output_image} -r ${iso9660_dir} ${source}

The potential content of ${grub_mkisofs_arguments}
looks good so far.
I assume you have already tested your use cases.


There remain opportunities for result size
reduction:

The result will be up to 426 kB larger than the
one of grub-mkisofs. (Modern mkisofs or
genisoimage would give you 300 kB extra.)

------------------------------------------------

You may add mkisofs option
  -no-pad
to avoid trailing padding of 300 kB which is only
needed if you later burn the image to a CD in
write mode TAO.
Alternatively you could allow option -no-pad in
the option interpreter of grub-mkrescue rather
than issueing:
    -*) 
        echo "Unrecognized option \`$option'" 1>&2

The burn program can eventually add padding.
xorriso -as cdrecord will by default use write
mode SAO if the file size is detectable.

------------------------------------------------

Another 64 to 126 kB can be saved by hiding the
fact that the target is a random access file.
One would replace
    -o ${output_image}
by
    | cat >${output_image}
This deprives the result of the capability to
show on overwriteable media a table-of-content
with older sessions.

------------------------------------------------

In my tests the size reduced result was 4 kB
smaller than the result from grub-mkisofs.


Have a nice day :)

Thomas

Re: Migrations to xorriso

[Thomas Schmitt]

Hi,

reviewing my grub-mkrescue 1.98 test script
i see these options which will cause the files
in /boot to have low block addresses:

   xorriso ... -as mkisofs ... \
   --sort-weight 0 / --sort-weight 1 /boot \
   ...

The boot catalog gets a low LBA by default.

I remember Vladimir mentioned that some BIOSes
need low addresses.
So probably one should add these options to
grub-mkrescue.in.


Vladimir Serbinenko wrote:
> @Thomas: grub-mkisofs was partially translated. Could you look into
> reusing translation strings for xorriso?

Currently there is no internationalization in
xorriso. I would probably need some advise and
an interested translator to make it ready for
that.



Have a nice day :)

Thomas

Re: Migrations to xorriso

[Vladimir 'φ-coder/phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 1670 bytes --]

Thomas Schmitt wrote:
> Hi,
>
> reviewing my grub-mkrescue 1.98 test script
> i see these options which will cause the files
> in /boot to have low block addresses:
>
>    xorriso ... -as mkisofs ... \
>    --sort-weight 0 / --sort-weight 1 /boot \
>    ...
>
> The boot catalog gets a low LBA by default.
>
> I remember Vladimir mentioned that some BIOSes
> need low addresses.
> So probably one should add these options to
> grub-mkrescue.in.
>
>   
Ok, will do.
> Vladimir Serbinenko wrote:
>   
>> @Thomas: grub-mkisofs was partially translated. Could you look into
>> reusing translation strings for xorriso?
>>     
>
> Currently there is no internationalization in
> xorriso. I would probably need some advise and
> an interested translator to make it ready for
> that.
>
>   
Actually it seems that xorriso doesn't have a lot of common strings with
grub-mkisofs so probably there is no much value in reusing strings.
As for advice: you already have automake so adding gettext should be
easy change in Makefile.am followed by marking all translatable strings
with _() and including proper header.
But the hic is if xorriso uses any like
printf("Device %s is %s.", devname, valid ? "valid" : "invalid");
will need to be changed to:
printf(valid ?_("Device %s is valid."):_("Device %s is invalid."), devname);
since string operations are untranslatable.

>
> Have a nice day :)
>
> Thomas
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 293 bytes --]

Re: Migrations to xorriso

[Thomas Schmitt]

Hi,

> I'm thinking to allow passing arbitrary options to xorriso by just
> putting it on command line.
> Do you recommend to switching to native xorriso interface?

There are differences how file names without "="
are handled.
xorriso maps /my/dir to /my/dir.
xorriso -as mkisofs maps /my/dir to /dir.
Since i expect scripts to operate grub-mkrescue,
i would be cautious with this change.

Lifting the ban on -*) would allow the user to
switch to xorriso CLI by giving argument "--".
grub-mkrescue would just have to put any unknown
argument into ${source}.
E.g.
  grub-mkrescue \
      --output=result.iso \
      -no-pad /my/os /my/payload \
      -- \
      -set_filter_r --zisofs /payload --

(I imagine that /os would be able to read the
 zisofs compressed /payload after booting.)


> This size saving matters only for floppies.
> Perhaps we should add an
> option --pcfloppy which will additionally
> disable all other platforms.

Sounds like a good idea.


> Also I find the way of configuring with "| cat >" quite ugly. Is there a
> reason not to have an option for this behaviour?

It happens automatically deep under xorriso.
xorriso sees the output file as libburn drive.
libburn recognizes the file type and chooses
an appropriate drive model: overwriteable
or sequential. xorriso then reacts on this
choice.

I could introduce an option. But one would then
have to wait for the next xorriso release to
become available in Debian.
So for now it seems better to use cat, if a
thorough diet is desired.


> > internationalization
> [...] gettext [...] 
> But the hic is if xorriso uses any like
> printf("Device %s is %s.", devname, valid ? "valid" : "invalid");

I would have to review the code for this.
xorriso -report_about HINT will not issue much
entertaining messages anyway.
(In general i believe it helps world peace if
 everybody learns some english.)


Seth Goldberg wrote:
> Solaris uses a ISO9660 filesystem image with individual
> compressed files, [...]
> The value to grub2, though, is unknown.

Compression seems appealing for CD images
with large payload or for old USB sticks.
Since the files of GRUB are small, one can
restrict compression to the other files of
the image, so that GRUB is not affected.

zisofs has the advantage to allow random
access inside the compressed files. User space
does not have to be aware of it. I have even
experienced better read speed on slow media.
The compression ratio is slightly inferior to
plain gzip, though.


Have a nice day :)

Thomas