From dd189692d40948d6445bbaeb8cb9bf9d15f54dc6 Mon Sep 17 00:00:00 2001 From: Kevin Hao Date: Tue, 24 Dec 2013 15:12:06 +0800 Subject: [PATCH] powerpc: enable the relocatable support for the fsl booke 32bit kernel 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 Signed-off-by: Scott Wood --- arch/powerpc/Kconfig | 2 +- arch/powerpc/kernel/fsl_booke_entry_mapping.S | 2 ++ arch/powerpc/kernel/head_fsl_booke.S | 34 +++++++++++++++++++ arch/powerpc/mm/fsl_booke_mmu.c | 28 +++++++++++++++ 4 files changed, 65 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index f0a893142cee..4bb52e6488ea 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -884,7 +884,7 @@ 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 a92c79be2728..f22e7e44fbf3 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 196950f29c00..19bd574bda9d 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -73,6 +73,30 @@ _ENTRY(_start); li r24,0 /* CPU number */ li r23,0 /* phys kernel start (high) */ +#ifdef CONFIG_RELOCATABLE + LOAD_REG_ADDR_PIC(r3, _stext) /* 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 +206,16 @@ _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 07ba45b0f07c..ce4a1163ddd3 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