Add yet another ugly hack to iscsiboot.c, this time to allow the user to
inhibit the shutdown/removal of the iSCSI INT13 device (and the network
devices, since they are required for the iSCSI device to function).
On the plus side, the fact that shutdown() now takes flags to
differentiate between shutdown-for-exit and shutdown-for-boot means that
another ugly hack (to allow returning via the PXE stack on BIOSes that
have broken INT 18 calls) will be easier.
I feel dirty.
We can just treat all non-kernel images as initrds, which matches our
behaviour for multiboot kernels. This allows us to eliminate initrd as
an image type, and treat the "initrd" command as just another synonym for
"imgfetch".
2.6.22+ kernels have an extra field in the bzimage_header structure to
indicate the maximum permitted command-line length. Use this if it is
available.
byte, rather than the number of permissible bytes (i.e. subtract one
from the value under the previous definition to get the value under
the new definition).
This avoids integer overflow on 64-bit kernels, where
bzhdr.initrd_addr_max may be 0xffffffffffffffff; under the old
behaviour we set mem_limit equal to initrd_addr_max+1, which meant it
ended up as zero. Kernel loads would fail with ENOBUFS.
