Commit 0a137736 authored by H. Peter Anvin's avatar H. Peter Anvin

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: default avatarH. Peter Anvin <hpa@zytor.com>
parent 5b11f1ce
......@@ -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
......@@ -131,11 +134,6 @@ relocated:
cld
rep stosb
/*
* Setup the stack for the decompressor
*/
leal boot_stack_end(%ebx), %esp
/*
* Do the decompression, and jump to the new kernel..
*/
......
......@@ -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..
*/
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment