This is based on the codes in the head_44x.S. The difference is that
the init tlb size we used is 64M. With this patch we can only load the
kernel at address between memstart_addr ~ memstart_addr + 64M. We will
fix this restriction in the following patches.
Signed-off-by: Kevin Hao <haoke...@gmail.com>
---
v3:
* Use the 64M align.
* typo fix.
v2: Move the code to set kernstart_addr and virt_phys_offset to a c function.
So we can expand it easily later.
arch/powerpc/Kconfig | 2 +-
arch/powerpc/kernel/fsl_booke_entry_mapping.S | 2 ++
arch/powerpc/kernel/head_fsl_booke.S | 37 +++++++++++++++++++++++++++
arch/powerpc/mm/fsl_booke_mmu.c | 28 ++++++++++++++++++++
4 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3bf72cd..57dc8f9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -859,7 +859,7 @@ config DYNAMIC_MEMSTART
config RELOCATABLE
bool "Build a relocatable kernel"
- depends on ADVANCED_OPTIONS && FLATMEM && 44x
+ depends on ADVANCED_OPTIONS && FLATMEM && (44x || FSL_BOOKE)
select NONSTATIC_KERNEL
help
This builds a kernel image that is capable of running at the
diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S
b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
index a92c79b..f22e7e4 100644
--- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S
+++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
@@ -176,6 +176,8 @@ skpinv: addi r6,r6,1 /*
Increment */
/* 7. Jump to KERNELBASE mapping */
lis r6,(KERNELBASE & ~0xfff)@h
ori r6,r6,(KERNELBASE & ~0xfff)@l
+ rlwinm r7,r25,0,0x03ffffff
+ add r6,r7,r6
#elif defined(ENTRY_MAPPING_KEXEC_SETUP)
/*
diff --git a/arch/powerpc/kernel/head_fsl_booke.S
b/arch/powerpc/kernel/head_fsl_booke.S
index 377bd81..f6ec9a3 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -73,6 +73,33 @@ _ENTRY(_start);
li r24,0 /* CPU number */
li r23,0 /* phys kernel start (high) */
+#ifdef CONFIG_RELOCATABLE
+ bl 0f /* Get our runtime address */
+0: mflr r3 /* Make it accessible */
+ addis r3,r3,(_stext - 0b)@ha
+ addi r3,r3,(_stext - 0b)@l /* Get our current runtime base */
+
+ /* Translate _stext address to physical, save in r23/r25 */
+ bl get_phys_addr
+ mr r23,r3
+ mr r25,r4
+
+ /*
+ * We have the runtime (virutal) address of our base.
+ * We calculate our shift of offset from a 64M page.
+ * We could map the 64M page we belong to at PAGE_OFFSET and
+ * get going from there.
+ */
+ lis r4,KERNELBASE@h
+ ori r4,r4,KERNELBASE@l
+ rlwinm r6,r25,0,0x3ffffff /* r6 = PHYS_START % 64M */
+ rlwinm r5,r4,0,0x3ffffff /* r5 = KERNELBASE % 64M */
+ subf r3,r5,r6 /* r3 = r6 - r5 */
+ add r3,r4,r3 /* Required Virtual Address */
+
+ bl relocate
+#endif
+
/* We try to not make any assumptions about how the boot loader
* setup or used the TLBs. We invalidate all mappings from the
* boot loader and load a single entry in TLB1[0] to map the
@@ -182,6 +209,16 @@ _ENTRY(__early_start)
bl early_init
+#ifdef CONFIG_RELOCATABLE
+#ifdef CONFIG_PHYS_64BIT
+ mr r3,r23
+ mr r4,r25
+#else
+ mr r3,r25
+#endif
+ bl relocate_init
+#endif
+
#ifdef CONFIG_DYNAMIC_MEMSTART
lis r3,kernstart_addr@ha
la r3,kernstart_addr@l(r3)
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 07ba45b..ce4a116 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -241,4 +241,32 @@ void setup_initial_memory_limit(phys_addr_t
first_memblock_base,
/* 64M mapped initially according to head_fsl_booke.S */
memblock_set_current_limit(min_t(u64, limit, 0x04000000));
}
+
+#ifdef CONFIG_RELOCATABLE
+notrace void __init relocate_init(phys_addr_t start)
+{
+ unsigned long base = KERNELBASE;
+
+ /*
+ * Relocatable kernel support based on processing of dynamic
+ * relocation entries.
+ * Compute the virt_phys_offset :
+ * virt_phys_offset = stext.run - kernstart_addr
+ *
+ * stext.run = (KERNELBASE & ~0x3ffffff) + (kernstart_addr & 0x3ffffff)
+ * When we relocate, we have :
+ *
+ * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
+ *
+ * hence:
+ * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
+ * (kernstart_addr & ~0x3ffffff)
+ *
+ */
+ kernstart_addr = start;
+ start &= ~0x3ffffff;
+ base &= ~0x3ffffff;
+ virt_phys_offset = base - start;
+}
+#endif
#endif
--
1.8.3.1
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