OPAL is not callable from 32-bit mode and the assembly code for it
may not even build (depending on how binutils was configured).

References: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=powerpcspe&ver=4.8.7-1&stamp=1479203712
Fixes: 656ad58ef19e ("powerpc/boot: Add OPAL console to epapr wrappers")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When configured with CONFIG_PPC_EARLY_DEBUG_OPAL=y the kernel expects
the OPAL entry and base addresses to be passed in r8 and r9
respectively. Currently the wrapper does not attempt to restore these
values before entering the decompressed kernel which causes the kernel
to branch into whatever happens to be in r9 when doing a write to the
OPAL console in early boot.

This patch adds a platform_ops hook that can be used to branch into the
new kernel. The OPAL console driver patches this at runtime so that if
the console is used it will be restored just prior to entering the
kernel.

Fixes: 656ad58ef19e ("powerpc/boot: Add OPAL console to epapr wrappers")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This commit broke boot on systems with an uncompressed kernel image,
namely systems using a cuImage. On such systems the compressed boot
image (boot wrapper, uncompressed kernel image, ..) is decompressed
by u-boot already, therefore the boot wrapper code sees an
uncompressed kernel image.

The old decompression code silently assumed an uncompressed kernel
image if it found no valid gzip signature, whilst the new code
bailed out in this case.

Fix this by re-introducing such a fallback if no valid compressed
image is found.

Fixes: 1b7898ee276b ("Use the pre-boot decompression API")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This patch adds an option to use XZ compression for the kernel image.

Currently this is only enabled for 64-bit Book3S targets, which is
roughly equivalent to the platforms that use the kernel's zImage
wrapper, and that have been tested.

The bulk of the 32-bit platforms and 64-bit BookE use uboot images,
which relies on uboot implementing XZ. In future we can enable XZ
support for those targets once someone has tested it.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This modifies the wrapper script so that the -Z option takes an argument
to specify the compression type. It can either be 'gz', 'xz' or 'none'.

The legazy --no-gzip and -z options are still supported and will set the
compression to none and gzip respectively, but they are not documented.

Only XZ -6 is used for compression rather than XZ -9. Using compression
levels higher than 6 requires the decompressor to build a large (64MB)
dictionary when decompressing and some environments cannot satisfy such
large allocations (e.g. POWER 6 LPAR partition firmware).

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This code is no longer used and can be removed.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Currently the powerpc boot wrapper has its own wrapper around zlib to
handle decompressing gzipped kernels. The kernel decompressor library
functions now provide a generic interface that can be used in the
pre-boot environment. This allows boot wrappers to easily support
different compression algorithms. This patch converts the wrapper to use
this new API, but does not add support for using new algorithms.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Most architectures allow the compression algorithm used to produced the
vmlinuz image to be selected as a kernel config option. In preperation
for supporting algorithms other than gzip in the powerpc boot wrapper
the makefile needs to be modified to use these config options.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The powerpc boot wrapper is potentially compiled with a separate
toolchain and/or toolchain flags than the rest of the kernel. The usual
case is a 64-bit big endian kernel builds a 32-bit big endian wrapper.

The main problem with this is that the wrapper does not have access to
the kernel headers (without a lot of gross hacks). To get around this
the required headers are copied into the build directory via several sed
scripts which rewrite problematic includes. This patch moves these
fixups out of the makefile into a separate .sed script file to clean up
makefile slightly.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Reword first paragraph of change log a little]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Some of the rules in the boot Makefile use @ to hide the command, this
means "make V=1" doesn't show them, which is confusing.

So use the Kbuild standard $(Q) which means KBUILD_VERBOSE=1 or V=1 will
work as expected.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>