Improve the debugging support of the PS3 bootwraper code:

 o Increase the size of the PS3 bootwrapper overlay from 256 to 512 bytes to
   allow for more debugging code in the overlay.
 o Use the dot symbol to set the size of __system_reset_overlay.  The
   assembler will then emit an error if the overlay code is too big.
 o Remove some unused instructions.
 o Update the text describing the PS3 bootwrapper overlay.
 o Add a check for null pointer writes.
 o Change hcall return value from s64.
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The PS3 bootwrapper files use instructions only available on 64-bit CPUs.
Add the code generation directive '.machine "ppc64"' for toolchains
configured for 32-bit CPUs.
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support to build the PS3 flash rom image and remove some unneeded
lmb calls.

The PS3's lv1 loader supports loading gzipped binary images from flash
rom to addr zero. The loader enters the image at addr 0x100.

In this implementation a bootwrapper overlay is use to arrange for the
kernel to be loaded to addr zero and to have a suitable bootwrapper
entry at 0x100.  To construct the rom image, 0x100 bytes from offset
0x100 in the kernel is copied to the bootwrapper symbol
__system_reset_kernel.  The 0x100 bytes at the bootwrapper symbol
__system_reset_overlay is then copied to offset 0x100.  At runtime the
bootwrapper program copies the 0x100 bytes at __system_reset_kernel to
addr 0x100.

zImage.ps3 is a wrapped image that contains a flat device tree, an lv1
compatible entry point, and an optional initrd.  otheros.bld is the gzip
compresed rom image built from zImage.ps3.  otheros.bld is suitable for
programming into the PS3 boot flash memory.
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>