[PATCH] ARM: 2816/1: Shark: boot kernel images bigger than 1 MB

Patch from Alexander Schulz

Up to now, shark kernels were limited to one megabyte compressed
size. As the kernels get bigger, this becomes more and more
uncomfortable. So I added a loop to copy 3 MB instead of one
and added some comments.

Signed-off-by: Alexander Schulz <alex@shark-linux.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 33 insertions, 9 deletions

diff --git a/arch/arm/boot/compressed/head-shark.S b/arch/arm/boot/compressed/head-shark.S
index 848f60e5429b..089c560e07f1 100644
--- a/arch/arm/boot/compressed/head-shark.S
+++ b/arch/arm/boot/compressed/head-shark.S
@@ -63,8 +63,8 @@ __beginning:	mov	r4, r0				@ save the entry to the firmware
 
                 mov     pc, r2
 
-__copy_target:  .long   0x08508000
-__copy_end:     .long   0x08608000
+__copy_target:  .long   0x08507FFC
+__copy_end:     .long   0x08607FFC
                 
                 .word   _start
                 .word   __bss_start
@@ -73,9 +73,10 @@ __copy_end:	.long	0x08608000
 __temp_stack:   .space 128
 
 __mmu_off:
-                adr     r0, __ofw_data
+                adr     r0, __ofw_data                  @ read the 1. entry of the memory map
                 ldr     r0, [r0, #4]
                 orr     r0, r0, #0x00600000
+                sub     r0, r0, #4
         
                 ldr     r1, __copy_end
                 ldr     r3, __copy_target
@@ -89,20 +90,43 @@ __mmu_off:
  * from 0x08500000 to 0x08508000 if we have only 8MB
  */
 
+/* As we get more 2.6-kernels it gets more and more
+ * uncomfortable to be bound to kernel images of 1MB only.
+ * So we add a loop here, to be able to copy some more.
+ * Alexander Schulz 2005-07-17
+ */
+
+                mov     r4, #3                          @ How many megabytes to copy
+
+
+__MoveCode:     sub     r4, r4, #1
         
 __Copy:         ldr     r2, [r0], #-4
                 str     r2, [r1], #-4
                 teq     r1, r3
                 bne     __Copy
+
+                /* The firmware maps us in blocks of 1 MB, the next block is
+                   _below_ the last one. So our decrementing source pointer
+                   ist right here, but the destination pointer must be increased
+                   by 2 MB */
+                add     r1, r1, #0x00200000
+                add     r3, r3, #0x00100000
+
+                teq     r4, #0
+                bne     __MoveCode
+
+
                 /* and jump to it */
-                adr     r2, __go_on
-                adr     r0, __ofw_data
+                adr     r2, __go_on                     @ where we want to jump
+                adr     r0, __ofw_data                  @ read the 1. entry of the memory map
                 ldr     r0, [r0, #4]
-                sub     r2, r2, r0
-                sub     r2, r2, #0x00500000
-                ldr     r0, __copy_target
+                sub     r2, r2, r0                      @ we are mapped add 0e50 now, sub that (-0e00)
+                sub     r2, r2, #0x00500000             @ -0050
+                ldr     r0, __copy_target               @ and add 0850 8000 instead
+                add     r0, r0, #4
                 add     r2, r2, r0
-                mov     pc, r2
+                mov     pc, r2                          @ and jump there
 
 __go_on:
                 adr     sp, __temp_stack