x86: Allow BOOT_TRAMPOLINE to be changed without needing manual

modification of the trampoline GDT. Adjust trampoline base to
0x94000.
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S
index ca2337af239b1e38f1a2c29ac8a051f34c8df2d3..ab4c46e7281ebfe4d460c62274bcbb0a466eb6dd 100644 (file)
--- a/xen/arch/x86/boot/trampoline.S
+++ b/xen/arch/x86/boot/trampoline.S
@@ -22,13 +22,22 @@ trampoline_realmode_entry:
 idt_48: .word   0, 0, 0 # base = limit = 0
 gdt_48: .word   6*8-1
         .long   bootsym_phys(trampoline_gdt)
+        .align  8
 trampoline_gdt:
-        .quad   0x0000000000000000     /* 0x0000: unused */
-        .quad   0x00cf9a000000ffff     /* 0x0008: ring 0 code, 32-bit mode */
-        .quad   0x00af9a000000ffff     /* 0x0010: ring 0 code, 64-bit mode */
-        .quad   0x00cf92000000ffff     /* 0x0018: ring 0 data */
-        .quad   0x00009a090000ffff     /* 0x0020: real-mode code @ 0x90000 */
-        .quad   0x000092090000ffff     /* 0x0028: real-mode data @ 0x90000 */
+        /* 0x0000: unused */
+        .quad   0x0000000000000000
+        /* 0x0008: ring 0 code, 32-bit mode */
+        .quad   0x00cf9a000000ffff
+        /* 0x0010: ring 0 code, 64-bit mode */
+        .quad   0x00af9a000000ffff
+        /* 0x0018: ring 0 data */
+        .quad   0x00cf92000000ffff
+        /* 0x0020: real-mode code @ BOOT_TRAMPOLINE */
+        .long   0x0000ffff | ((BOOT_TRAMPOLINE & 0x00ffff) << 16)
+        .long   0x00009a00 | ((BOOT_TRAMPOLINE & 0xff0000) >> 16)
+        /* 0x0028: real-mode data @ BOOT_TRAMPOLINE */
+        .long   0x0000ffff | ((BOOT_TRAMPOLINE & 0x00ffff) << 16)
+        .long   0x00009200 | ((BOOT_TRAMPOLINE & 0xff0000) >> 16)
 
 cpuid_ext_features:
         .long   0
@@ -142,7 +151,7 @@ trampoline_boot_cpu_entry:
         mov     %ax,%es
         mov     %ax,%ss
 
-        /* Stack grows down from 0x93000. Initialise IDT and enable irqs. */
+        /* Stack grows down from +0x3000. Initialise IDT and enable irqs. */
         mov     $0x3000,%sp
         lidt    bootsym(rm_idt)
         sti

diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index 698868fc74051f0a13be5c32aab9432366767b78..669d0e0ea5b61be5fbf97ba32739fac2199dd026 100644 (file)
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -93,7 +93,7 @@
 
 #define CONFIG_DMA_BITSIZE 32
 
-#define BOOT_TRAMPOLINE 0x90000
+#define BOOT_TRAMPOLINE 0x94000
 #define bootsym_phys(sym)                                 \
     (((unsigned long)&(sym)-(unsigned long)&trampoline_start)+BOOT_TRAMPOLINE)
 #define bootsym(sym)                                      \