Messages in this thread Patch in this message |  | | From | Yinghai Lu <> | Subject | [PATCH v6 19/27] x86, boot: update comments about entries for 64bit image | Date | Thu, 13 Dec 2012 14:02:13 -0800 |
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Now 64bit entry is fixed on 0x200, can not be changed anymore.
Update the comments to reflect that.
Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- arch/x86/boot/compressed/head_64.S | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 5c80b94..5ba0c95 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -37,6 +37,12 @@ __HEAD .code32 ENTRY(startup_32) + /* + * 32bit entry is 0, could not be changed! + * If we come here directly from a bootloader, + * kernel(text+data+bss+brk) ramdisk, zero_page, command line + * all need to be under 4G limit. + */ cld /* * Test KEEP_SEGMENTS flag to see if the bootloader is asking @@ -182,20 +188,18 @@ ENTRY(startup_32) lret ENDPROC(startup_32) - /* - * Be careful here startup_64 needs to be at a predictable - * address so I can export it in an ELF header. Bootloaders - * should look at the ELF header to find this address, as - * it may change in the future. - */ .code64 .org 0x200 ENTRY(startup_64) /* + * 64bit entry is 0x200, could not be changed! * We come here either from startup_32 or directly from a - * 64bit bootloader. If we come here from a bootloader we depend on - * an identity mapped page table being provied that maps our - * entire text+data+bss and hopefully all of memory. + * 64bit bootloader. + * If we come here from a bootloader, kernel(text+data+bss+brk), + * ramdisk, zero_page, command line could be above 4G. + * We depend on an identity mapped page table being provided + * that maps our entire kernel(text+data+bss+brk), and hopefully + * all of memory. */ #ifdef CONFIG_EFI_STUB /* -- 1.7.10.4
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