Each architecture must define the following functions in kernel/$ARCH.sh:

  arch_get_kernel_flavour ()

    Prints a string describing the flavour of kernel to install. This can be
    in whatever scheme you like; it just has to be in sync with the other
    architecture-specific functions, where it's used.

    May expect $ARCH and $SUBARCH to be set to the architecture and
    subarchitecture (if applicable) respectively.

    This function should describe the kernel flavour in sufficiently general
    terms as to be able to test the usability of kernels of any major
    version. As such, it is not a good idea to make this function
    conditional on $KERNEL_MAJOR. If you need radically different kernel
    names depending on the kernel major version, you should handle that in
    the other architecture-specific functions.

    Returns zero if successful, or non-zero otherwise. If non-zero, it
    should print some kind of warning to syslog explaining why.

  arch_check_usable_kernel (kernel, flavour)

    Test whether a kernel is usable at all. For the purposes of this test,
    we assume that SMP is usable on UP and vice versa (is this safe?). Some
    architectures just have a hierarchy of optimized kernels, whereas some
    have subarchitectures that are incompatible at the kernel level. This
    function should cope with both cases.

    Note that by default any postfix (starting with a hyphen) is allowed
    after the flavor. This allows for custom kernels and also, for example,
    for kernel meta packages for stable kernel updates that have a postfix
    to distinguish them from the regular kernel meta packages.
    This means that if a specific postfix (such as -smp, or -bigmem) is not
    allowed, this should be tested explicitly.

    The same goes for prefixes: any prefix before the flavor is allowed by
    default.

    Returns zero if the kernel is usable on this flavour, or non-zero
    otherwise.

  arch_get_kernel (flavour)

    Print the preferred kernels for this flavour, one per line, in order of
    preference.

    No return value; must not fail. (If there's a problem, one of the two
    functions above should already have failed.)

Shell variables all functions may expect:

  ARCH
    The architecture (as returned by udpkg --print-architecture).
  SUBARCH
    The subarchitecture (as returned by archdetect).
  CPUINFO
    The location of /proc/cpuinfo, parameterised for the benefit of the test
    suite.
  OFCPUS
    Open Firmware /cpus directory. Useful on OF platforms when CPUINFO grepping
    won't work.
  KERNEL_MAJOR
    The major version of the running kernel, e.g. 2.6.
  KERNEL_VERSION
    The full version of the running kernel, e.g. 2.6.8.
  KERNEL_FLAVOUR
    The flavour of the running kernel, e.g. 486, 686-bigmem or ixp4xx.
  MACHINE
    The machine hardware name (as returned by uname -m).
  NUMCPUS
    The number of CPUs in the machine. Will only be set if /var/numcpus
    exists, and may not be very accurate (ie, 2 for any SMP machine).
    Only of use when grepping CPUINFO won't work.

Please update the regression tests in the tests/ directory when making
changes here. In particular, calls to inspect the kernel version or
files in /proc need support in the test suite so that the full test
suite can be run for all architectures on any architecture.