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Commit 22a57f58 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, setup: Allow global variables and functions in the decompressor 



In order for global variables and functions to work in the
decompressor, we need to fix up the GOT in assembly code.

Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4C57382E.8050501@zytor.com>
parent 70b0d22d

arch/x86/boot/compressed/head_32.S

+13 −0
Original line number Diff line number Diff line
@@ -123,6 +123,19 @@ relocated: 
	shrl	$2, %ecx

	rep	stosl



/*

 * Adjust our own GOT

 */

	leal	_got(%ebx), %edx

	leal	_egot(%ebx), %ecx

1:

	cmpl	%ecx, %edx

	jae	2f

	addl	%ebx, (%edx)

	addl	$4, %edx

	jmp	1b

2:



/*

 * Do the decompression, and jump to the new kernel..

 */

arch/x86/boot/compressed/head_64.S

+13 −0
Original line number Diff line number Diff line
@@ -279,6 +279,19 @@ relocated: 
	shrq	$3, %rcx

	rep	stosq



/*

 * Adjust our own GOT

 */

	leaq	_got(%rip), %rdx

	leaq	_egot(%rip), %rcx

1:

	cmpq	%rcx, %rdx

	jae	2f

	addq	%rbx, (%rdx)

	addq	$8, %rdx

	jmp	1b

2:

	

/*

 * Do the decompression, and jump to the new kernel..

 */

arch/x86/boot/compressed/vmlinux.lds.S

+6 −0
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ SECTIONS 
		*(.rodata.*)

		_erodata = . ;

	}

	.got : {

		_got = .;

		KEEP(*(.got.plt))

		KEEP(*(.got))

		_egot = .;

	}

	.data :	{

		_data = . ;

		*(.data)