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Subject[PATCH v6 19/27] x86, boot: update comments about entries for 64bit image
Date
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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