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path: root/arch/powerpc/boot/crt0.S
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2011-04-20powerpc/boot: Allow building the zImage wrapper as a relocatable ET_DYNMichael Ellerman
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>
2007-06-07[POWERPC] Fix building of COFF zImagesPaul Mackerras
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>
2007-04-13[POWERPC] bootwrapper: missing relocation in crt0.SMilton Miller
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>
2007-03-26[POWERPC] New reg.h for the zImageDavid Gibson
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[POWERPC] bootwrapper: Allow platforms to call library zImage_startMilton Miller
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>
2007-03-13[POWERPC] zImage: Cleanup and improve zImage entry pointDavid Gibson
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>
2006-03-16[PATCH] powerpc: correct cacheflush loop in zImageOlaf Hering
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>
2006-01-14powerpc: Make COFF zImages for old 32-bit powermacsPaul Mackerras
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>
2005-11-18[PATCH] ppc boot: replace string labels with numbersOlaf Hering
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>
2005-11-16powerpc: Move ppc64 boot wrapper code over to arch/powerpcPaul Mackerras
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>