It could certainly be improved using Elf macros and byteswapping
routines, but the initial version of the code is organised to be a
single file program with limited dependencies. yaboot is the same.
Please scream if you want a total rewrite.
Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This reverts commit 91a0030295, plus
commit 0dcd440120 ("powerpc: Revert CHRP
boot wrapper to real-base = 12MB on 32-bit") which depended on it.
Commit 91a00302 was causing NVRAM corruption on some pSeries machines,
for as-yet unknown reasons, so this reverts it until the cause is
identified.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Commit 9b09c6d909 ("powerpc: Change the
default link address for pSeries zImage kernels") changed the
real-base value in the CHRP note added by addnote to the zImage from
12MB to 32MB. It turns out that this causes unnecessary extra reboots
on old 32-bit CHRP machines. This therefore adds a -r flag to addnote
to allow us to specify what real-base value it should put in the CHRP
note, and adjusts the wrapper script to pass -r c00000 to addnote when
making a zImage for a CHRP machine. Also, CHRP machines ignore the
RPA note, so we don't need to arrange for it to be the same as the
kernel's.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit 9b09c6d909 ("powerpc: Change the
default link address for pSeries zImage kernels") changed the
real-base value in the CHRP note added by the addnote program from
12MB to 32MB to give more space for Open Firmware to load the zImage.
(The real-base value says where we want OF to position itself in
memory.) However, this change was ineffective on most pSeries
machines, because the RPA note added by addnote has the "ignore me"
flag set to 1. This was intended to tell OF to ignore just the RPA
note, but has the side effect of also making OF ignore the CHRP note
(at least on most pSeries machines).
To solve this we have to set the "ignore me" flag to 0 in the RPA
note. (We can't just omit the RPA note because that is equivalent to
having an RPA note with default values, and the default values are not
what we want.) However, then we have to make sure the values in the
zImage's RPA note match up with the values that the kernel supplies
later in prom_init.c with either the ibm,client-architecture-support
call or the process-elf-header call in prom_send_capabilities().
So this sets the "ignore me" flag in the RPA note in addnote to 0, and
adjusts the RPA note values in addnote.c and in prom_init.c to be
consistent with each other and with the values in ibm_architecture_vec.
However, since the wrapper is independent of the kernel, this doesn't
ensure that the notes will stay consistent. To ensure that, this adds
code to addnote.c so that it can extract the kernel's RPA note from
the kernel binary and put that in the zImage. To that end, we put the
kernel's fake ELF header (which contains the kernel's RPA note) into
its own section, and arrange for wrapper to pull out that section with
objcopy and pass it to addnote, which then extracts the RPA note from
it and transfers it to the zImage.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently we set the start of the .text section to be 4Mb for pSeries.
In situations where the zImage is > 8Mb we'll fail to boot (due to
overlapping with OF). Move .text in a zImage from 4MB to 64MB
(well past OF).
We still will not be able to load large zImage unless we also move OF,
to that end, add a note to the zImage ELF to move OF to 32Mb. If this
is the very first kernel booted then we'll need to move OF manually by
setting real-base.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This also extends the code to handle 32-bit ELF vmlinux files as well
as 64-bit ones. This is sufficient for booting on new-world 32-bit
powermacs (i.e. all recent machines).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cédric Le Goater