ipl: Allow to boot beyond the 2GB disk limit (on most machines)

Most newer-generation PA-RISC machines provide firmware support for the
ENTRY_IO_BBLOCK_IN (ARG=16) PDC option which addresses sectors in terms
of 2048 byte blocks. This feature overcomes the limitations of the old
ENTRY_IO_BOOTIN (ARG=0) PDC option, which uses byte offsets and thus
requires that boot files are located inside the first 2GB of the drive.

This palo patch checks the IODC_FEATURES (byte 10) of the IODC block of
the boot device, and if the rightmost bit is set, it will use the
ENTRY_IO boot block input support.

Palo will output at startup if the machines has the 2GB limitation:
-> Boot limited to sectors below 2GB: YES/NO

Signed-off-by: Helge Deller <deller@gmx.de>
15 files changed