[Xen-devel] [PATCH] xen/arm: build as zImage

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

The zImage format is extremely simple: it only consists of a magic
number and 2 addresses in a specific position (see
http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html#d0e309).

Some bootloaders expect a zImage; considering that it doesn't cost us
much to build Xen compatible with the format, make it so.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


diff --git a/xen/arch/arm/head.S b/xen/arch/arm/head.S
index 25c4cfe..de9cdb2 100644
--- a/xen/arch/arm/head.S
+++ b/xen/arch/arm/head.S
@@ -22,6 +22,9 @@
 #include <asm/processor-ca15.h>
 #include <asm/asm_defns.h>
 
+#define ZIMAGE_MAGIC_NUMBER 0x016f2818
+#define XEN_PHYS_ADDRESS    0x80000000
+
 #define PT_PT  0xe7f /* nG=1, AF=1, SH=10, AP=01, NS=1, ATTR=111, T=1, P=1 */
 #define PT_MEM 0xe7d /* nG=1, AF=1, SH=10, AP=01, NS=1, ATTR=111, T=0, P=1 */
 #define PT_DEV 0xe71 /* nG=1, AF=1, SH=10, AP=01, NS=1, ATTR=100, T=0, P=1 */
@@ -52,6 +55,18 @@
         * or the initial pagetable code below will need adjustment. */
        .global start
 start:
+
+       .rept   7
+       mov     r0, r0
+       .endr
+       mov     r0, r0
+       b       1f
+
+       .word   ZIMAGE_MAGIC_NUMBER                             @ Magic numbers 
to help the loader
+       .word   (_start + XEN_PHYS_ADDRESS)             @ absolute load/run 
zImage address
+       .word   (_end + XEN_PHYS_ADDRESS)               @ zImage end address
+
+1:
        cpsid aif                    /* Disable all interrupts */
 
        /* Save the bootloader arguments in less-clobberable registers */

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel