Commit Graph

16 Commits

Author SHA1 Message Date
Tobin C. Harding eb039161da powerpc/asm: Convert .llong directives to .8byte
.llong is an undocumented PPC specific directive. The generic
equivalent is .quad, but even better (because it's self describing) is
.8byte.

Convert all .llong directives to .8byte.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-31 14:26:47 +10:00
Jeremy Kerr 7f664cf9e4 powerpc/boot: don't clobber r6 and r7 in epapr boot
We use r6 and r7 for epapr boot, but the current pre-C init will clobber
both of these.

This change does a simple replacement, of r6 -> r12 and r7 -> r13, so
that we hit platform init with these registers intact.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-16 18:58:35 +11:00
Jeremy Kerr 8c06f0d910 powerpc/boot: Fix stack corruption in epapr entry point
Currently, a 64-bit little-endian zImage.epapr won't boot in epapr mode,
as we never return from platform_init.

Before entering C, we initialise our stack by setting r1 16 bytes below
the end of the _bss_stack:

  stwu	r0,-16(r1)	/* establish a stack frame */

However, the called function will save the caller's lr in the caller's
frame's lr save area, at -16(r1) to -32(r1).

This means that writes to the fdt variable will corrupt the saved link
register:

 0000000020c06018 l     O .bss   0000000000001000 _bss_stack
 0000000020c07018 l     O .bss   0000000000000008 fdt

We'll need at least 32 bytes in the initial stack frame, to handle the
LR save area. We bump this to 112 bytes, as that'll be the max required
by ABIv1.

Thanks to Alistair Popple for debugging help.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-16 18:58:34 +11:00
Cédric Le Goater 147c05168f powerpc/boot: Add support for 64bit little endian wrapper
The code is only slightly modified : entry points now use the
FIXUP_ENDIAN trampoline to switch endian order. The 32bit wrapper
is kept for big endian kernels and 64bit is enforced for little
endian kernels with a PPC64_BOOT_WRAPPER config option.

The linker script is generated using the kernel preprocessor flags
to make use of the CONFIG_* definitions and the wrapper script is
modified to take into account the new elf64ppc format.

Finally, the zImage file is compiled as a position independent
executable (-pie) which makes it loadable at any address by the
firmware.

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-28 17:36:21 +10:00
Cédric Le Goater f16e968499 powerpc/boot: Modify entry point for 64bit
This patch adds support a 64bit wrapper entry point. As in 32bit, the
entry point does its own relocation and can be loaded at any address
by the firmware.

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-28 17:36:12 +10:00
Cédric Le Goater 93d3921042 powerpc/boot: Define a routine to enter prom
This patch defines a 'prom' routine similar to 'enter_prom' in the
kernel.

The difference is in the MSR which is built before entering prom. Big
endian order is enforced as in the kernel but 32bit mode is not. It
prepares ground for the next patches which will introduce Little endian
order.

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-28 17:36:08 +10:00
Michael Ellerman 6975a783d7 powerpc/boot: Allow building the zImage wrapper as a relocatable ET_DYN
This patch adds code, linker script and makefile support to allow
building the zImage wrapper around the kernel as a position independent
executable.  This results in an ET_DYN instead of an ET_EXEC ELF output
file, which can be loaded at any location by the firmware and will
process its own relocations to work correctly at the loaded address.

This is of interest particularly since the standard ePAPR image format
must be an ET_DYN (although this patch alone is not sufficient to
produce a fully ePAPR compliant boot image).

Note for now we don't enable building with -pie for anything.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-20 16:59:20 +10:00
Paul Mackerras f40e524eae [POWERPC] Fix building of COFF zImages
The COFF zImage (for booting oldworld powermacs) wasn't being built
correctly because the procedure descriptor in crt0.S for the zImage
entry point wasn't declared as .globl, and therefore wasn't getting
pulled in from wrapper.a by the linker.  This adds the necessary
.globl statement.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-07 22:21:31 +10:00
Milton Miller f4bdbfc41b [POWERPC] bootwrapper: missing relocation in crt0.S
crt0.S had provisions to provide run address relocaton to got2 and
cache flush, but not on the bss clear or stack pointer load.  Apply
the same fixup for them.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-04-13 03:55:16 +10:00
David Gibson e5a2072bd4 [POWERPC] New reg.h for the zImage
This patch adds a reg.h to the zImage code, with common definitions
for accessing system registers.  For now, this includes functions for
retrieving the PVR and the stack pointer.  This patch then uses the
new reg.h to let start() display the running stack address without
having to explicitly pass the stack as a parameter from the asm code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-26 15:11:20 +10:00
Milton Miller 160cc3ece7 [POWERPC] bootwrapper: Allow platforms to call library zImage_start
Some platforms might need to run some code before the zImage start, but
could otherwise use the bss clear and relocation code.   Export the
start address strongly as zImage_start_lib.

Signed-off-by: Milton Miller <miltonm@bga.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-26 15:11:20 +10:00
David Gibson cd197ffcf1 [POWERPC] zImage: Cleanup and improve zImage entry point
This patch re-organises the way the zImage wrapper code is entered, to
allow more flexibility on platforms with unusual entry conditions.
After this patch, a platform .o file has two options:

1) It can define a _zimage_start, in which case the platform code gets
   control from the very beginning of execution.  In this case the
   platform code is responsible for relocating the zImage if necessary,
   clearing the BSS, performing any platform specific initialization, and
   finally calling start() to load and enter the kernel.

2) It can define platform_init().  In this case the generic crt0.S
   handles initial entry, and calls platform_init() before calling
   start().  The signature of platform_init() is changed, however, to
   take up to 5 parameters (in r3..r7) as they come from the platform's
   initial loader, instead of a fixed set of parameters based on OF's
   usage.

   When using the generic crt0.S, the platform .o can optionally
   supply a custom stack to use, using the BSS_STACK() macro.  If this
   is not supplied, the crt0.S will assume that the loader has
   supplied a usable stack.

In either case, the platform code communicates information to the
generic code (specifically, a PROM pointer for OF systems, and/or an
initrd image address supplied by the bootloader) via a global
structure "loader_info".

In addition the wrapper script is rearranged to ensure that the
platform .o is always linked first.  This means that platforms where
the zImage entry point is at a fixed address or offset, rather than
being encoded in the binary header can be supported using option (1).

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-13 13:35:03 +11:00
Olaf Hering eacb1962d4 [PATCH] powerpc: correct cacheflush loop in zImage
Correct the loop for cacheflush. No idea where I copied the code from,
but the original does not work correct. Maybe the flush is not needed.

Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-16 16:54:57 +11:00
Paul Mackerras 66a45dd362 powerpc: Make COFF zImages for old 32-bit powermacs
This adds code to build zImage.coff and/or zImage.initrd.coff when
CONFIG_PPC32 and CONFIG_PPC_PMAC are defined.  It also restructures
the OF client code and adds some workarounds for OF quirks on the
older machines.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-14 15:04:06 +11:00
Olaf Hering 68643cfb87 [PATCH] ppc boot: replace string labels with numbers
Replacing the string labels with numbers saves 117 bytes in the final zImage.
These local labels are not discared.

Signed-off-by: Olaf Hering <olh@suse.de>

 arch/powerpc/boot/crt0.S |   23 +++++++++++------------
 1 files changed, 11 insertions(+), 12 deletions(-)
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-18 13:18:16 +11:00
Paul Mackerras 94b212c29f powerpc: Move ppc64 boot wrapper code over to arch/powerpc
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>
2005-11-16 13:52:21 +11:00