*/
.text
- adr r0, LC0
- ldmia r0, {r1, r2, r3, r5, r6, r11, ip}
- ldr sp, [r0, #28]
+
#ifdef CONFIG_AUTO_ZRELADDR
@ determine final kernel image address
mov r4, pc
#else
ldr r4, =zreladdr
#endif
- subs r0, r0, r1 @ calculate the delta offset
- @ if delta is zero, we are
- beq not_relocated @ running at the address we
- @ were linked at.
+ bl cache_on
+
+restart: adr r0, LC0
+ ldmia r0, {r1, r2, r3, r5, r6, r9, r11, r12}
+ ldr sp, [r0, #32]
+
+ /*
+ * We might be running at a different address. We need
+ * to fix up various pointers.
+ */
+ sub r0, r0, r1 @ calculate the delta offset
+ add r5, r5, r0 @ _start
+ add r6, r6, r0 @ _edata
+#ifndef CONFIG_ZBOOT_ROM
+ /* malloc space is above the relocated stack (64k max) */
+ add sp, sp, r0
+ add r10, sp, #0x10000
+#else
/*
- * We're running at a different address. We need to fix
- * up various pointers:
- * r5 - zImage base address (_start)
- * r6 - size of decompressed image
- * r11 - GOT start
- * ip - GOT end
+ * With ZBOOT_ROM the bss/stack is non relocatable,
+ * but someone could still run this code from RAM,
+ * in which case our reference is _edata.
*/
- add r5, r5, r0
+ mov r10, r6
+#endif
+
+/*
+ * Check to see if we will overwrite ourselves.
+ * r4 = final kernel address
+ * r5 = start of this image
+ * r9 = size of decompressed image
+ * r10 = end of this image, including bss/stack/malloc space if non XIP
+ * We basically want:
+ * r4 >= r10 -> OK
+ * r4 + image length <= r5 -> OK
+ */
+ cmp r4, r10
+ bhs wont_overwrite
+ add r10, r4, r9
+ cmp r10, r5
+ bls wont_overwrite
+
+/*
+ * Relocate ourselves past the end of the decompressed kernel.
+ * r5 = start of this image
+ * r6 = _edata
+ * r10 = end of the decompressed kernel
+ * Because we always copy ahead, we need to do it from the end and go
+ * backward in case the source and destination overlap.
+ */
+ /* Round up to next 256-byte boundary. */
+ add r10, r10, #256
+ bic r10, r10, #255
+
+ sub r9, r6, r5 @ size to copy
+ add r9, r9, #31 @ rounded up to a multiple
+ bic r9, r9, #31 @ ... of 32 bytes
+ add r6, r9, r5
+ add r9, r9, r10
+
+1: ldmdb r6!, {r0 - r3, r10 - r12, lr}
+ cmp r6, r5
+ stmdb r9!, {r0 - r3, r10 - r12, lr}
+ bhi 1b
+
+ /* Preserve offset to relocated code. */
+ sub r6, r9, r6
+
+ bl cache_clean_flush
+
+ adr r0, BSYM(restart)
+ add r0, r0, r6
+ mov pc, r0
+
+wont_overwrite:
+/*
+ * If delta is zero, we are running at the address we were linked at.
+ * r0 = delta
+ * r2 = BSS start
+ * r3 = BSS end
+ * r4 = kernel execution address
+ * r7 = architecture ID
+ * r8 = atags pointer
+ * r11 = GOT start
+ * r12 = GOT end
+ * sp = stack pointer
+ */
+ teq r0, #0
+ beq not_relocated
add r11, r11, r0
- add ip, ip, r0
+ add r12, r12, r0
#ifndef CONFIG_ZBOOT_ROM
/*
* If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
* we need to fix up pointers into the BSS region.
- * r2 - BSS start
- * r3 - BSS end
- * sp - stack pointer
+ * Note that the stack pointer has already been fixed up.
*/
add r2, r2, r0
add r3, r3, r0
- add sp, sp, r0
/*
* Relocate all entries in the GOT table.
1: ldr r1, [r11, #0] @ relocate entries in the GOT
add r1, r1, r0 @ table. This fixes up the
str r1, [r11], #4 @ C references.
- cmp r11, ip
+ cmp r11, r12
blo 1b
#else
cmphs r3, r1 @ _end < entry
addlo r1, r1, r0 @ table. This fixes up the
str r1, [r11], #4 @ C references.
- cmp r11, ip
+ cmp r11, r12
blo 1b
#endif
cmp r2, r3
blo 1b
- /*
- * The C runtime environment should now be setup
- * sufficiently. Turn the cache on, set up some
- * pointers, and start decompressing.
- */
- bl cache_on
-
- mov r1, sp @ malloc space above stack
- add r2, sp, #0x10000 @ 64k max
-
/*
- * Check to see if we will overwrite ourselves.
- * r4 = final kernel address
- * r5 = start of this image
- * r6 = size of decompressed image
- * r2 = end of malloc space (and therefore this image)
- * We basically want:
- * r4 >= r2 -> OK
- * r4 + image length <= r5 -> OK
+ * The C runtime environment should now be setup sufficiently.
+ * Set up some pointers, and start decompressing.
+ * r4 = kernel execution address
+ * r7 = architecture ID
+ * r8 = atags pointer
*/
- cmp r4, r2
- bhs wont_overwrite
- add r0, r4, r6
- cmp r0, r5
- bls wont_overwrite
-
- mov r5, r2 @ decompress after malloc space
- mov r0, r5
+ mov r0, r4
+ mov r1, sp @ malloc space above stack
+ add r2, sp, #0x10000 @ 64k max
mov r3, r7
bl decompress_kernel
-
- add r0, r0, #127 + 128 @ alignment + stack
- bic r0, r0, #127 @ align the kernel length
-/*
- * r0 = decompressed kernel length
- * r1-r3 = unused
- * r4 = kernel execution address
- * r5 = decompressed kernel start
- * r7 = architecture ID
- * r8 = atags pointer
- * r9-r12,r14 = corrupted
- */
- add r1, r5, r0 @ end of decompressed kernel
- adr r2, reloc_start
- ldr r3, LC1
- add r3, r2, r3
-1: ldmia r2!, {r9 - r12, r14} @ copy relocation code
- stmia r1!, {r9 - r12, r14}
- ldmia r2!, {r9 - r12, r14}
- stmia r1!, {r9 - r12, r14}
- cmp r2, r3
- blo 1b
- mov sp, r1
- add sp, sp, #128 @ relocate the stack
-
bl cache_clean_flush
- ARM( add pc, r5, r0 ) @ call relocation code
- THUMB( add r12, r5, r0 )
- THUMB( mov pc, r12 ) @ call relocation code
-
-/*
- * We're not in danger of overwriting ourselves. Do this the simple way.
- *
- * r4 = kernel execution address
- * r7 = architecture ID
- */
-wont_overwrite: mov r0, r4
- mov r3, r7
- bl decompress_kernel
- b call_kernel
+ bl cache_off
+ mov r0, #0 @ must be zero
+ mov r1, r7 @ restore architecture number
+ mov r2, r8 @ restore atags pointer
+ mov pc, r4 @ call kernel
.align 2
.type LC0, #object
.word __bss_start @ r2
.word _end @ r3
.word _start @ r5
- .word _image_size @ r6
+ .word _edata @ r6
+ .word _image_size @ r9
.word _got_start @ r11
.word _got_end @ ip
.word user_stack_end @ sp
-LC1: .word reloc_end - reloc_start
.size LC0, . - LC0
#ifdef CONFIG_ARCH_RPC
* On exit,
* r0, r1, r2, r3, r9, r10, r12 corrupted
* This routine must preserve:
- * r4, r5, r6, r7, r8
+ * r4, r7, r8
*/
.align 5
cache_on: mov r3, #8 @ cache_on function
sub pc, lr, r0, lsr #32 @ properly flush pipeline
#endif
-/*
- * All code following this line is relocatable. It is relocated by
- * the above code to the end of the decompressed kernel image and
- * executed there. During this time, we have no stacks.
- *
- * r0 = decompressed kernel length
- * r1-r3 = unused
- * r4 = kernel execution address
- * r5 = decompressed kernel start
- * r7 = architecture ID
- * r8 = atags pointer
- * r9-r12,r14 = corrupted
- */
- .align 5
-reloc_start: add r9, r5, r0
- sub r9, r9, #128 @ do not copy the stack
- debug_reloc_start
- mov r1, r4
-1:
- .rept 4
- ldmia r5!, {r0, r2, r3, r10 - r12, r14} @ relocate kernel
- stmia r1!, {r0, r2, r3, r10 - r12, r14}
- .endr
-
- cmp r5, r9
- blo 1b
- mov sp, r1
- add sp, sp, #128 @ relocate the stack
- debug_reloc_end
-
-call_kernel: bl cache_clean_flush
- bl cache_off
- mov r0, #0 @ must be zero
- mov r1, r7 @ restore architecture number
- mov r2, r8 @ restore atags pointer
- mov pc, r4 @ call kernel
-
/*
* Here follow the relocatable cache support functions for the
* various processors. This is a generic hook for locating an
* On exit,
* r0, r1, r2, r3, r9, r12 corrupted
* This routine must preserve:
- * r4, r6, r7
+ * r4, r7, r8
*/
.align 5
cache_off: mov r3, #12 @ cache_off function
* On exit,
* r1, r2, r3, r9, r10, r11, r12 corrupted
* This routine must preserve:
- * r0, r4, r5, r6, r7
+ * r4, r6, r7, r8
*/
.align 5
cache_clean_flush:
#endif
.ltorg
-reloc_end:
.align
.section ".stack", "aw", %nobits
git.openpandora.org / pandora-kernel.git / commitdiff