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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/boot/compressed/head-shark.S
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm/boot/compressed/head-shark.S')
-rw-r--r--arch/arm/boot/compressed/head-shark.S115
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/head-shark.S b/arch/arm/boot/compressed/head-shark.S
new file mode 100644
index 000000000000..848f60e5429b
--- /dev/null
+++ b/arch/arm/boot/compressed/head-shark.S
@@ -0,0 +1,115 @@
+/* The head-file for the Shark
+ * by Alexander Schulz
+ *
+ * Does the following:
+ * - get the memory layout from firmware. This can only be done as long as the mmu
+ * is still on.
+ * - switch the mmu off, so we have physical addresses
+ * - copy the kernel to 0x08508000. This is done to have a fixed address where the
+ * C-parts (misc.c) are executed. This address must be known at compile-time,
+ * but the load-address of the kernel depends on how much memory is installed.
+ * - Jump to this location.
+ * - Set r8 with 0, r7 with the architecture ID for head.S
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+
+ .section ".start", "ax"
+
+ b __beginning
+
+__ofw_data: .long 0 @ the number of memory blocks
+ .space 128 @ (startaddr,size) ...
+ .space 128 @ bootargs
+ .align
+
+__beginning: mov r4, r0 @ save the entry to the firmware
+
+ mov r0, #0xC0 @ disable irq and fiq
+ mov r1, r0
+ mrs r3, cpsr
+ bic r2, r3, r0
+ eor r2, r2, r1
+ msr cpsr_c, r2
+
+ mov r0, r4 @ get the Memory layout from firmware
+ adr r1, __ofw_data
+ add r2, r1, #4
+ mov lr, pc
+ b ofw_init
+ mov r1, #0
+
+ adr r2, __mmu_off @ calculate physical address
+ sub r2, r2, #0xf0000000 @ openprom maps us at f000 virt, 0e50 phys
+ adr r0, __ofw_data
+ ldr r0, [r0, #4]
+ add r2, r2, r0
+ add r2, r2, #0x00500000
+
+ mrc p15, 0, r3, c1, c0
+ bic r3, r3, #0xC @ Write Buffer and DCache
+ bic r3, r3, #0x1000 @ ICache
+ mcr p15, 0, r3, c1, c0 @ disabled
+
+ mov r0, #0
+ mcr p15, 0, r0, c7, c7 @ flush I,D caches on v4
+ mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4
+ mcr p15, 0, r0, c8, c7 @ flush I,D TLBs on v4
+
+ bic r3, r3, #0x1 @ MMU
+ mcr p15, 0, r3, c1, c0 @ disabled
+
+ mov pc, r2
+
+__copy_target: .long 0x08508000
+__copy_end: .long 0x08608000
+
+ .word _start
+ .word __bss_start
+
+ .align
+__temp_stack: .space 128
+
+__mmu_off:
+ adr r0, __ofw_data
+ ldr r0, [r0, #4]
+ orr r0, r0, #0x00600000
+
+ ldr r1, __copy_end
+ ldr r3, __copy_target
+
+/* r0 = 0x0e600000 (current end of kernelcode)
+ * r3 = 0x08508000 (where it should begin)
+ * r1 = 0x08608000 (end of copying area, 1MB)
+ * The kernel is compressed, so 1 MB should be enough.
+ * copy the kernel to the beginning of physical memory
+ * We start from the highest address, so we can copy
+ * from 0x08500000 to 0x08508000 if we have only 8MB
+ */
+
+
+__Copy: ldr r2, [r0], #-4
+ str r2, [r1], #-4
+ teq r1, r3
+ bne __Copy
+ /* and jump to it */
+ adr r2, __go_on
+ adr r0, __ofw_data
+ ldr r0, [r0, #4]
+ sub r2, r2, r0
+ sub r2, r2, #0x00500000
+ ldr r0, __copy_target
+ add r2, r2, r0
+ mov pc, r2
+
+__go_on:
+ adr sp, __temp_stack
+ add sp, sp, #128
+ adr r0, __ofw_data
+ mov lr, pc
+ b create_params
+
+ mov r8, #0
+ mov r7, #15