Re: [Bug-xorriso] About run xorriso under Win32

[gary jiang]

Hi Thomas,

On 2014/11/21 19:35, Thomas Schmitt wrote:
> Hi,
>
> since all attempts failed to let libisofs read the announced
> amount of bytes from the EL Torito boot image for BIOS, i need
> to get an impression what bytes are missing.
> My plan is to dump the read data into a file, so that it can
> be compared with the original isolinux.bin on disk.
>
> I tested the following change set. Maybe you have to use
> a different file path than "/tmp/boot_image_by_xorriso.bin"
> which is more appropriate for Cygwin:
>
> ==================================================================
> --- libisofs/eltorito.c 2014-11-20 12:15:35 +0000
> +++ libisofs/eltorito.c 2014-11-21 10:42:10 +0000
> @@ -24,6 +24,8 @@
>   #include <string.h>
>   #include <stdio.h>
>   
> +#include <errno.h>
> +
>   /**
>    * This table should be written with the actual values at offset
>    * 8 of boot image, when used ISOLINUX boot loader
> @@ -1197,6 +1199,18 @@
>               if (ret >= 0)
>                  iso_msg_submit(t->image->id, ISO_FILE_READ_ERROR, 0,
>           "Cannot read all bytes from El Torito boot image for boot info 
> table");
> +
> +            if (ret >= 0) {
> +                FILE *fp = NULL;
> +                fp = fopen("/tmp/boot_image_by_xorriso.bin", "wb");
> +                if (fp == NULL) {
> +                    fprintf(stderr, "libisofs_DEBUG: 
> fopen(/tmp/boot_image_by_xorriso.bin) failed with errno= %d\n", errno);
I suppose the above "errno" means ferror(fp).
> +                } else {
> +                    fwrite(buf, ret, 1, fp);
> +                    fclose(fp);
> +                    fprintf(stderr, "libisofs_DEBUG: Dumped retrieved data to 
> /tmp/boot_image_by_xorriso.bin\n");
> +                }
> +            }
> +
>               return (ret < 0) ? ret : (int) ISO_FILE_READ_ERROR;
>           }
> ==================================================================
>   
> Please make above change to xorriso-1.3.9 and redo the failing
> xorriso run with -boot-info-table.
>
> The message
>    libisofs_DEBUG: Dumped retrieved data to /tmp/boot_image_by_xorriso.bin
> is supposed to appear several lines before
>    libisofs: FAILURE : Cannot read all bytes from El Torito boot image for boot 
> info table
> because the latter has to travel through the asynchronous
> message queues of libisofs and xorriso.
>
> Then send both files: The original isolinux.bin and the file
> which was created during the failed xorriso run.
Please see the attached.
> Further it might be interesting to see what xorriso writes into
> an ISO image if it does not fail to patch the boot image.
>    xorriso -as mkisofs -o isolinux.iso -no-pad isolinux/isolinux.bin
> should produce a very small ISO image isolinux.iso with only
> a copy of isolinux.bin in it. This image would be of interest.
>
>
> --------------------------------------------------------------------
> Now for the compile time problems:
>
> > 1. libisofs/system_area.h:179: error: conflicting type for 'iso_crc32_gpt'
> >      libisofs/libisofs.h:4055: error: previous declaration of 'iso_crc32_gpt' 
> > was here
> Good catch. Obviously i forgot to delete the declaration
> in system_area.h when i moved it to libisofs.h in order to
> make it a part of the public API.
> Now fixed by:
>    http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/revision/1174
Thanks for the fix.
> > 2. libisofs/util.c: In function 'iso_datetime_7':
> >      libisofs/util.c:1577: error: wrong type argument to unary minus
> > 3. xorriso/misc_funct.c:649: error: invalid operands to binary -
> HAVE_TM_GMTOFF is indeed the trigger, but the type of the
> global "timezone" variable is the culprit.
>
> I cannot find a Cygwin man page about timezone resp. tzset(3).
> My Linux manual prescribes to include <time.h> which is not done
> by libisofs/util.h. But xorriso/misc_funct.c does include it.
>
> Do you know about any Cygwin documentation about "timezone" ?
>
> In
>    https://cygwin.com/viewvc/src/winsup/cygwin/include/cygwin/time.h?view=markup
> i see
>
>    #ifndef __timezonefunc__
>    extern long timezone __asm__ (_SYMSTR (_timezone));
>    #endif
>
> and riddle whether __timezonefunc__ is defined.
> If so, then the complained code lines probably try to
> negate resp. subtract a function pointer.
Generally, the "date" command should display timezone info, however the 
"date"
under Cygwin doesn't include it, I am not sure what is the problem, I am 
downloading
the latest Cygwin then see what will happen with it, perhaps the latest 
Cygwin works
ok with xorriso.

$ date - Cygwin
Sat Nov 22 11:36:07        2014

$ date - Linux
Thu Nov 20 21:31:16 PST 2014
> > I comment the related lines out just for a workaround.
> A better workaround would be to replace timezone by 0.
>
> libisofs/util.c:
> -    tzoffset = ( - timezone / 60 / 15 ) + 4 * tm.tm_isdst;
> +    tzoffset = 4 * tm.tm_isdst;
>
> xorriso/misc_funct.c:
> -     seconds-= timezone - result_tm.tm_isdst * 3600;
> +     seconds-= 0 - result_tm.tm_isdst * 3600;
>
> But for automatic handling at ./configure time, i need some
> clue about what's going on. Then i can write a test which
> sets a macro.
Thanks, I tried it, and the result is same.
> > the iso generated with only efi boot option still can't boot efi
> > machine, and seems it has some relationship with the libisofs/util.c since I
> > did the following change:
> > //tzoffset = ( - timezone / 60 / 15 ) + 4 * tm.tm_isdst;
> >      fprintf(stderr, "here is the second compile error\n");
> > And the debug info is displayed lots of time when generate iso,
> I doubt that faulty time stamps can cause EFI to fail booting.
>
> The EFI firmware is supposed to read the address of the El Torito
> boot catalog from the boot record of CD, DVD, or BD. This catalog
> contains records about the available boot images. Images for EFI
> are recognizable by having platform id code 0xEF.
> No time stamps are involved up to this point.
>
> As soon as EFI picked its boot image, the job of the ISO boot
> equipment is done. EFI will operate on the FAT filesystem image
> which was prepared by GRUB2 and put into the ISO unaltered.
>
> If you boot from USB stick or other hard-disk-like devices then
> the position of the FAT image file in the ISO must be marked by
> MBR and/or GPT partition. This would be the job of SYSLINUX
> program isohybrid --gpt or of the related options of
> xorriso -as mkisofs.
> For BIOS:
>    -isohybrid-mbr ...where.installed.by.syslinux.../isohdpfx.bin
> For EFI as addon to option -e (like -no-emul-boot):
>    -isohybrid-gpt-basdat
> Again, no timestamps are involved until the FAT filesystem is
> found by EFI.
Thanks for the analysis.

Best Regards,
Gary
> Have a nice day :)
>
> Thomas

isolinux.bin
Description: Binary data

isolinux-xorriso.bin
Description: Binary data