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Diffstat (limited to 'arch/x86_64/boot/compressed/head.S')
-rw-r--r--arch/x86_64/boot/compressed/head.S19
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86_64/boot/compressed/head.S b/arch/x86_64/boot/compressed/head.S
index c353a92..f9d5692 100644
--- a/arch/x86_64/boot/compressed/head.S
+++ b/arch/x86_64/boot/compressed/head.S
@@ -54,6 +54,15 @@ startup_32:
1: popl %ebp
subl $1b, %ebp
+/* setup a stack and make sure cpu supports long mode. */
+ movl $user_stack_end, %eax
+ addl %ebp, %eax
+ movl %eax, %esp
+
+ call verify_cpu
+ testl %eax, %eax
+ jnz no_longmode
+
/* Compute the delta between where we were compiled to run at
* and where the code will actually run at.
*/
@@ -159,13 +168,21 @@ startup_32:
/* Jump from 32bit compatibility mode into 64bit mode. */
lret
+no_longmode:
+ /* This isn't an x86-64 CPU so hang */
+1:
+ hlt
+ jmp 1b
+
+#include "../../kernel/verify_cpu.S"
+
/* Be careful here startup_64 needs to be at a predictable
* address so I can export it in an ELF header. Bootloaders
* should look at the ELF header to find this address, as
* it may change in the future.
*/
.code64
- .org 0x100
+ .org 0x200
ENTRY(startup_64)
/* We come here either from startup_32 or directly from a
* 64bit bootloader. If we come here from a bootloader we depend on