[syslinux] Changes to get CD to boot on EFI System.

Thomas Schmitt scdbackup at gmx.net
Mon Apr 4 13:01:32 PDT 2016


Jernej Simončič wrote:
> As long as you have cygwin with development tools installed, it's just
> ./configure && make.

autotools magic. I myself have few clue of contemporary MS-Windows.

> https://eternallybored.org/misc/xorriso/xorriso-1.4.2-cygwin32.zip

Thank you for flying xorriso.

> > > oscdimg.exe -a -m -o -j1
> > > -bootdata:2#p0,e,bcd\isolinux\boot.bin#pEF,e,bcd\boot\efiboot.ima CD
> > > sysresccd.iso

I read
to propose this translation

  xorriso -as mkisofs -v -J \
    -b /isolinux/boot.bin \
      -no-emul-boot -boot-load-size 4 -boot-info-table \
    -eltorito-alt-boot \
    -e /boot/efiboot.ima \
      -no-emul-boot \
    -o sysresccd.iso \

Options -b and -e want the image file path in the ISO, not on hard disk.
I assume that "CD\isolinux\boot.bin" will show up as "/isolinux/boot.bin".
Please adjust to "/cd/isolinux/boot.bin" if i am wrong.

For detail info see
  man xorrisofs

You get Rock Ridge for free. If this makes undesired differences when
mounting by Linux, you may prevent it by xorrisofs option  --norock .
(Or use mount(8) option -o "norock" to let Linux mount Joliet as next
 best name space.)

Not translated:
  -a Displays the allocation summary for files and directories.
  -m Ignores the maximum size limit of an image.
  -o Optimizes storage by encoding duplicate files only once using
     a MD5 hashing algorithm to compare files.
Option -a might be similar to xorriso command -find ... -exec report_lba.
Option -m is a bit obscure to me. ISO 9660 max size is 2 exp 43 = 8 TiB.
Option -o looks like an interesting feature.

I wonder how oscdimg.exe knows that it has to apply boot-info-table
patching to the boot.bin file.

Have a nice day :)


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