x86: cleanup boot-heap usage

The kernel decompressor wrapper uses memory located beyond the
end of the image. This might lead to hard to debug problems,
but even if it can be proven to be safe, it is at the very
least unclean. I don't see any advantages either, unless you
count it not being zeroed out as an advantage. This patch
moves the boot-heap area to the bss segment.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/boot/compressed/head_32.S

@@ -130,7 +130,7 @@ relocated:
 /*
  * Setup the stack for the decompressor
  */
-	leal stack_end(%ebx), %esp
+	leal boot_stack_end(%ebx), %esp
 
 /*
  * Do the decompression, and jump to the new kernel..
@@ -142,8 +142,8 @@ relocated:
 	pushl %eax	# input_len
 	leal input_data(%ebx), %eax
 	pushl %eax	# input_data
-	leal _end(%ebx), %eax
-	pushl %eax	# end of the image as third argument
+	leal boot_heap(%ebx), %eax
+	pushl %eax	# heap area as third argument
 	pushl %esi	# real mode pointer as second arg
 	call decompress_kernel
 	addl $20, %esp
@@ -181,7 +181,10 @@ relocated:
 	jmp *%ebp
 
 .bss
+/* Stack and heap for uncompression */
 .balign 4
-stack:
-	.fill 4096, 1, 0
-stack_end:
+boot_heap:
+	.fill BOOT_HEAP_SIZE, 1, 0
+boot_stack:
+	.fill BOOT_STACK_SIZE, 1, 0
+boot_stack_end: