linux.git/arch/powerpc/kernel/vmlinux.lds.S, branch v2.6.29

powerpc: Make dummy section a valid note header

2009-01-13T03:47:58+00:00

We are declaring the dummy section (used to work around a binutils
bug) as PT_NOTE, but we don't have enough bytes for it to be a valid
note header, and kexec userspace complains:

Warning: Elf Note name is not null terminated
Warning: append= option is not passed. Using the first kernel root partition
Warning: Elf Note name is not null terminated

Instead of using the arbitray value 0xf177 (aka "fill"), declare a
no-name no-description note of type 0.

Signed-off-by: Milton Miller 
Signed-off-by: Benjamin Herrenschmidt

powerpc/mm: Introduce MMU features

2008-12-21T03:21:16+00:00

We're soon running out of CPU features and I need to add some new
ones for various MMU related bits, so this patch separates the MMU
features from the CPU features.  I moved over the 32-bit MMU related
ones, added base features for MMU type families, but didn't move
over any 64-bit only feature yet.

Signed-off-by: Benjamin Herrenschmidt 
Acked-by: Kumar Gala 
Signed-off-by: Paul Mackerras

Revert "powerpc: Sync RPA note in zImage with kernel's RPA note"

2008-10-31T11:36:21+00:00

This reverts commit 91a00302959545a9ae423e99732b1e46eb19e877, plus
commit 0dcd440120ef12879ff34fc78d7e4abf171c79e4 ("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

powerpc: Work around ld bug in older binutils

2008-10-31T05:11:52+00:00

Commit 549e8152de8039506f69c677a4546e5427aa6ae7 ("powerpc: Make the
64-bit kernel as a position-independent executable") added lines to
vmlinux.lds.S to add the extra sections needed to implement a
relocatable kernel.  However, those lines seem to trigger a bug in
older versions of GNU ld (such as 2.16.1) when building a
non-relocatable kernel.  Since ld 2.16.1 is still a popular choice for
cross-toolchains, this adds an #ifdef to vmlinux.lds.S so the added
lines are only included when building a relocatable kernel.

Signed-off-by: Paul Mackerras

powerpc: Sync RPA note in zImage with kernel's RPA note

2008-10-10T04:55:19+00:00

Commit 9b09c6d909dfd8de96b99b9b9c808b94b0a71614 ("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 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Make the 64-bit kernel as a position-independent executable

2008-09-15T18:08:38+00:00

This implements CONFIG_RELOCATABLE for 64-bit by making the kernel as
a position-independent executable (PIE) when it is set.  This involves
processing the dynamic relocations in the image in the early stages of
booting, even if the kernel is being run at the address it is linked at,
since the linker does not necessarily fill in words in the image for
which there are dynamic relocations.  (In fact the linker does fill in
such words for 64-bit executables, though not for 32-bit executables,
so in principle we could avoid calling relocate() entirely when we're
running a 64-bit kernel at the linked address.)

The dynamic relocations are processed by a new function relocate(addr),
where the addr parameter is the virtual address where the image will be
run.  In fact we call it twice; once before calling prom_init, and again
when starting the main kernel.  This means that reloc_offset() returns
0 in prom_init (since it has been relocated to the address it is running
at), which necessitated a few adjustments.

This also changes __va and __pa to use an equivalent definition that is
simpler.  With the relocatable kernel, PAGE_OFFSET and MEMORY_START are
constants (for 64-bit) whereas PHYSICAL_START is a variable (and
KERNELBASE ideally should be too, but isn't yet).

With this, relocatable kernels still copy themselves down to physical
address 0 and run there.

Signed-off-by: Paul Mackerras

powerpc: Make sure _etext is after all kernel text

2008-09-03T10:53:26+00:00

This makes core_kernel_text() (and therefore kernel_text_address())
return the correct result.  Currently all the __devinit routines (at
least) will not be considered to be kernel text.

This is just a quick fix for 2.6.27 - hopefully we will be able to fix
this better in 2.6.28.

Signed-off-by: Stephen Rothwell 
Signed-off-by: Paul Mackerras

powerpc: Fix compile error with binutils 2.15

2008-07-25T05:44:40+00:00

My previous patch to fix compilation with binutils-2.17 causes
a "file truncated" build error from ld with binutils 2.15 (and
possibly older), and a warning with 2.16 and 2.17.

This fixes it.

Signed-off-by: Segher Boessenkool 
Acked-by: Chuck Meade 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix build bug with binutils < 2.18 and GCC < 4.2

2008-07-22T00:39:37+00:00

binutils < 2.18 has a bug that makes it misbehave when taking an
ELF file with all segments at load address 0 as input.  This
happens when running "strip" on vmlinux, because of the AT() magic
in this linker script.  People using GCC >= 4.2 won't run into
this problem, because the "build-id" support will put some data
into the "notes" segment (at a non-zero load address).

To work around this, we force some data into both the "dummy"
segment and the kernel segment, so the dummy segment will get a
non-zero load address.  It's not enough to always create the
"notes" segment, since if nothing gets assigned to it, its load
address will be zero.

Signed-off-by: Segher Boessenkool 
Tested-By: Milton Miller 
Signed-off-by: Benjamin Herrenschmidt

Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build

2008-07-15T05:44:51+00:00

Manual fixup of:

	arch/powerpc/Kconfig