Commit-ID: 0a137736704ef9af719409933b3c33e138461786 Gitweb: http://git.kernel.org/tip/0a137736704ef9af719409933b3c33e138461786 Author: H. Peter Anvin <hpa@xxxxxxxxx> AuthorDate: Fri, 8 May 2009 16:27:41 -0700 Committer: H. Peter Anvin <hpa@xxxxxxxxx> CommitDate: Fri, 8 May 2009 17:18:47 -0700 x86, boot: set up the decompression stack as early as possible Set up the decompression stack as soon as we know where it needs to go. That way we have a full-service stack as soon as possible, rather than relying on the BP_scratch field. Note that the stack does need to be empty during bss zeroing (or else the stack needs to be moved out of the bss segment, which is also an option.) [ Impact: cleanup, minor paranoia ] Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx> --- arch/x86/boot/compressed/head_32.S | 10 ++++------ arch/x86/boot/compressed/head_64.S | 16 ++++++++-------- 2 files changed, 12 insertions(+), 14 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 59425e1..d7245cf 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -88,6 +88,9 @@ ENTRY(startup_32) addl $4095, %ebx andl $~4095, %ebx + /* Set up the stack */ + leal boot_stack_end(%ebx), %esp + /* * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. @@ -122,7 +125,7 @@ ENDPROC(startup_32) relocated: /* - * Clear BSS + * Clear BSS (stack is currently empty) */ xorl %eax, %eax leal _bss(%ebx), %edi @@ -132,11 +135,6 @@ relocated: rep stosb /* - * Setup the stack for the decompressor - */ - leal boot_stack_end(%ebx), %esp - -/* * Do the decompression, and jump to the new kernel.. */ movl output_len(%ebx), %eax diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 5bc9052..a0b1842 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -249,6 +249,13 @@ ENTRY(startup_64) addq $(32768 + 18 + 4095), %rbx andq $~4095, %rbx + /* Set up the stack */ + leaq boot_stack_end(%rbx), %rsp + + /* Zero EFLAGS */ + pushq $0 + popfq + /* * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. @@ -273,7 +280,7 @@ ENTRY(startup_64) relocated: /* - * Clear BSS + * Clear BSS (stack is currently empty) */ xorq %rax, %rax leaq _bss(%rbx), %rdi @@ -282,13 +289,6 @@ relocated: cld rep stosb - /* Setup the stack */ - leaq boot_stack_end(%rip), %rsp - - /* zero EFLAGS after setting rsp */ - pushq $0 - popfq - /* * Do the decompression, and jump to the new kernel.. */ -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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