BMC/Intel-BMC/linux.git/arch/powerpc/boot/crt0.S, branch dev

powerpc/boot: don't clobber r6 and r7 in epapr boot

2015-03-16T07:58:35+00:00

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 Signed-off-by: Michael Ellerman

powerpc/boot: Fix stack corruption in epapr entry point

2015-03-16T07:58:34+00:00

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 Signed-off-by: Michael Ellerman

powerpc/boot: Add support for 64bit little endian wrapper

2014-04-28T07:36:21+00:00

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 Signed-off-by: Benjamin Herrenschmidt

powerpc/boot: Modify entry point for 64bit

2014-04-28T07:36:12+00:00

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 Signed-off-by: Benjamin Herrenschmidt

powerpc/boot: Define a routine to enter prom

2014-04-28T07:36:08+00:00

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 Signed-off-by: Benjamin Herrenschmidt

powerpc/boot: Allow building the zImage wrapper as a relocatable ET_DYN

2011-04-20T06:59:20+00:00

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 Signed-off-by: David Gibson Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

[POWERPC] Fix building of COFF zImages

2007-06-07T12:21:31+00:00

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

[POWERPC] bootwrapper: missing relocation in crt0.S

2007-04-12T17:55:16+00:00

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 Signed-off-by: Paul Mackerras

[POWERPC] New reg.h for the zImage

2007-03-26T05:11:20+00:00

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 Signed-off-by: Paul Mackerras

[POWERPC] bootwrapper: Allow platforms to call library zImage_start

2007-03-26T05:11:20+00:00

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 Acked-by: David Gibson Signed-off-by: Paul Mackerras