Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / x86 / purgatory / setup-x86_64.S

diff --git a/kernel/arch/x86/purgatory/setup-x86_64.S b/kernel/arch/x86/purgatory/setup-x86_64.S
new file mode 100644 (file)
index 0000000..fe3c91b
--- /dev/null
+++ b/kernel/arch/x86/purgatory/setup-x86_64.S
@@ -0,0 +1,58 @@
+/*
+ * purgatory:  setup code
+ *
+ * Copyright (C) 2003,2004  Eric Biederman (ebiederm@xmission.com)
+ * Copyright (C) 2014 Red Hat Inc.
+ *
+ * This code has been taken from kexec-tools.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+       .text
+       .globl purgatory_start
+       .balign 16
+purgatory_start:
+       .code64
+
+       /* Load a gdt so I know what the segment registers are */
+       lgdt    gdt(%rip)
+
+       /* load the data segments */
+       movl    $0x18, %eax     /* data segment */
+       movl    %eax, %ds
+       movl    %eax, %es
+       movl    %eax, %ss
+       movl    %eax, %fs
+       movl    %eax, %gs
+
+       /* Setup a stack */
+       leaq    lstack_end(%rip), %rsp
+
+       /* Call the C code */
+       call purgatory
+       jmp     entry64
+
+       .section ".rodata"
+       .balign 16
+gdt:   /* 0x00 unusable segment
+        * 0x08 unused
+        * so use them as the gdt ptr
+        */
+       .word   gdt_end - gdt - 1
+       .quad   gdt
+       .word   0, 0, 0
+
+       /* 0x10 4GB flat code segment */
+       .word   0xFFFF, 0x0000, 0x9A00, 0x00AF
+
+       /* 0x18 4GB flat data segment */
+       .word   0xFFFF, 0x0000, 0x9200, 0x00CF
+gdt_end:
+
+       .bss
+       .balign 4096
+lstack:
+       .skip 4096
+lstack_end: