boot0.S changes:
+ import a patch from Christoph Mallon to rearrange the various
print functions and save another couple of bytes;
+ implement the suggestion in PR 70531 to enable booting from
any valid partition because even the extended partitions that
were previously in our kill list may contain a valid boot loader.
This simplifies the code and saves some bytes;
+ followwing up PR 127764, implement conditional code to preserve
the 'Volume ID' which might be used by other OS (NT, XP, Vista)
and is located at offset 0x1b8. This requires a relocation of the
parameter block within the boot sector -- there is no other
possible workaround.
To address this, boot0cfg has been updated to handle both
versions of the boot code;
+ slightly rearrange the strings printed in the menus to make
the code buildable with all options. Given the tight memory
budget, this means that with certain options we need to
shrink or remove certain labels.
and especially:
make -DVOLUME_LABEL -DPXE the default options.
This means that the newly built boot0 block will preserve the
Volume ID, and has the (hidden) option F6 to boot from INT18/PXE.
I think the extra functionality is well worth the change.
The most visible difference here is that the 'Default: ' string
now becomes 'Boot: ' (it can be reverted to the old value
but then we need to nuke 1/2 partition name or entries to
make up for the extra room).
boot0cfg changes:
+ modify the code to recognise the new boot0 structure (with the
relocated options block to make room for the Volume id).
+ add two options, '-i xxxx-xxxx' to set the volume ID, -e c
to modify the character printed in case of bad input
PR: 127764 70531
Submitted by: Christoph Mallon (portions)
MFC after: 4 weeks
ae3096705c