On 06/16/11 19:44, Michal Simek wrote:
Changes:
- Find out address where kernel runs
- Create the first 256MB TLB from online detected address
Limitations:
- Kernel must be aligned to 256MB
Backport:
- Changes in page.h are backported from newer kernel version
mmu_mapin_ram function has to reflect offset in memory start.
memstart_addr and kernstart_addr are setup directly from asm
code to ensure that only ppc44x is affected.
Signed-off-by: Michal Simek<mon...@monstr.eu>
---
arch/powerpc/Kconfig | 3 ++-
arch/powerpc/include/asm/page.h | 7 ++++++-
arch/powerpc/kernel/head_44x.S | 28 ++++++++++++++++++++++++++++
arch/powerpc/mm/44x_mmu.c | 6 +++++-
4 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 45c9683..34c521e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -796,7 +796,8 @@ config LOWMEM_CAM_NUM
config RELOCATABLE
bool "Build a relocatable kernel (EXPERIMENTAL)"
- depends on EXPERIMENTAL&& ADVANCED_OPTIONS&& FLATMEM&& FSL_BOOKE
+ depends on EXPERIMENTAL&& ADVANCED_OPTIONS&& FLATMEM
+ depends on FSL_BOOKE || (44x&& !SMP)
help
This builds a kernel image that is capable of running at the
location the kernel is loaded at (some alignment restrictions may
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 4940662..e813cc2 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -108,8 +108,13 @@ extern phys_addr_t kernstart_addr;
#define pfn_to_kaddr(pfn) __va((pfn)<< PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr)>> PAGE_SHIFT)
-#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
+#ifdef CONFIG_BOOKE
+#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) - PHYSICAL_START +
KERNELBASE))
+#define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
+#else
+#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET -
MEMORY_START))
#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
+#endif
/*
* Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index d80ce05..6a63d32 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -59,6 +59,17 @@ _ENTRY(_start);
* of abatron_pteptrs
*/
nop
+
+#ifdef CONFIG_RELOCATABLE
+ bl jump /* Find our address */
+ nop
+jump: mflr r25 /* Make it accessible */
+ /* just for and */
+ lis r26, 0xfffffff0@h
+ ori r26, r26, 0xfffffff0@l
+ and. r21, r25, r26
+#endif
Hmm. So we are assuming we are running from a 1:1 mapping at the entry.
It is much more safe to read our tlb entry and use the RPN instead.
+#ifdef CONFIG_RELOCATABLE
+ /* load physical address where kernel runs */
+ mr r4,r21
+#else
/* Kernel is at PHYSICAL_START */
lis r4,PHYSICAL_START@h
ori r4,r4,PHYSICAL_START@l
+#endif
/* Load the kernel PID = 0 */
li r0,0
@@ -258,6 +274,18 @@ skpinv: addi r4,r4,1 /*
Increment */
mr r5,r29
mr r6,r28
mr r7,r27
+
+#ifdef CONFIG_RELOCATABLE
+ /* save kernel and memory start */
+ lis r25,kernstart_addr@h
+ ori r25,r25,kernstart_addr@l
+ stw r21,4(r25)
1) You have to use ERPN value in the higher word of kernel_start_addr.
2) You have to account for the (KERNEL_BASE - PAGE_OFFSET) shift for
kernel_start_addr.
+
+ lis r25,memstart_addr@h
+ ori r25,r25,memstart_addr@l
+ stw r21,4(r25)
+#endif
+
Suzuki
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