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authorPaul Mackerras <paulus@samba.org>2008-10-08 14:03:29 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-10-10 15:55:19 +1100
commit91a00302959545a9ae423e99732b1e46eb19e877 (patch)
tree180192f6f8d2b97c332d970fc07278010287f3f5 /arch/powerpc/kernel/vmlinux.lds.S
parent58f467ce1476f5b2a347cee3a32275b737fbd667 (diff)
powerpc: Sync RPA note in zImage with kernel's RPA note
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 <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/vmlinux.lds.S')
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index e6927fb2e655..b39c27ed7919 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -203,6 +203,9 @@ SECTIONS
*(.rela*)
}
+ /* Fake ELF header containing RPA note; for addnote */
+ .fakeelf : AT(ADDR(.fakeelf) - LOAD_OFFSET) { *(.fakeelf) }
+
/* freed after init ends here */
. = ALIGN(PAGE_SIZE);
__init_end = .;