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Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
-rw-r--r--arch/x86/boot/compressed/head_64.S41
1 files changed, 13 insertions, 28 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 723c72dfd7b..2b9f2510507 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -90,16 +90,8 @@ ENTRY(startup_32)
movl $CONFIG_PHYSICAL_START, %ebx
#endif
- /* Replace the compressed data size with the uncompressed size */
- subl input_len(%ebp), %ebx
- movl output_len(%ebp), %eax
- addl %eax, %ebx
- /* Add 8 bytes for every 32K input block */
- shrl $12, %eax
- addl %eax, %ebx
- /* Add 32K + 18 bytes of extra slack and align on a 4K boundary */
- addl $(32768 + 18 + 4095), %ebx
- andl $~4095, %ebx
+ /* Target address to relocate to for decompression */
+ addl $z_extract_offset, %ebx
/*
* Prepare for entering 64 bit mode
@@ -224,6 +216,9 @@ ENTRY(startup_64)
* If it is a relocatable kernel then decompress and run the kernel
* from load address aligned to 2MB addr, otherwise decompress and
* run the kernel from CONFIG_PHYSICAL_START
+ *
+ * We cannot rely on the calculation done in 32-bit mode, since we
+ * may have been invoked via the 64-bit entry point.
*/
/* Start with the delta to where the kernel will run at. */
@@ -237,17 +232,8 @@ ENTRY(startup_64)
movq %rbp, %rbx
#endif
- /* Replace the compressed data size with the uncompressed size */
- movl input_len(%rip), %eax
- subq %rax, %rbx
- movl output_len(%rip), %eax
- addq %rax, %rbx
- /* Add 8 bytes for every 32K input block */
- shrq $12, %rax
- addq %rax, %rbx
- /* Add 32K + 18 bytes of extra slack and align on a 4K boundary */
- addq $(32768 + 18 + 4095), %rbx
- andq $~4095, %rbx
+ /* Target address to relocate to for decompression */
+ leaq z_extract_offset(%rbp), %rbx
/* Set up the stack */
leaq boot_stack_end(%rbx), %rsp
@@ -292,13 +278,12 @@ relocated:
/*
* Do the decompression, and jump to the new kernel..
*/
- pushq %rsi # Save the real mode argument
- movq %rsi, %rdi # real mode address
- leaq boot_heap(%rip), %rsi # malloc area for uncompression
- leaq input_data(%rip), %rdx # input_data
- movl input_len(%rip), %eax
- movq %rax, %rcx # input_len
- movq %rbp, %r8 # output
+ pushq %rsi /* Save the real mode argument */
+ movq %rsi, %rdi /* real mode address */
+ leaq boot_heap(%rip), %rsi /* malloc area for uncompression */
+ leaq input_data(%rip), %rdx /* input_data */
+ movl $z_input_len, %ecx /* input_len */
+ movq %rbp, %r8 /* output target address */
call decompress_kernel
popq %rsi