diff options
| -rw-r--r-- | arch/powerpc/Kconfig | 41 | ||||
| -rw-r--r-- | arch/powerpc/Makefile | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/reloc_32.S | 208 | ||||
| -rw-r--r-- | arch/powerpc/kernel/vmlinux.lds.S | 8 | ||||
| -rwxr-xr-x | arch/powerpc/relocs_check.pl | 14 |
6 files changed, 256 insertions, 23 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 8b323b7b0a6..2ad5ea82782 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -847,23 +847,30 @@ config DYNAMIC_MEMSTART load address. When this option is enabled, the compile time physical address CONFIG_PHYSICAL_START is ignored. -# Mapping based RELOCATABLE is moved to DYNAMIC_MEMSTART -# config RELOCATABLE -# bool "Build a relocatable kernel (EXPERIMENTAL)" -# depends on EXPERIMENTAL && ADVANCED_OPTIONS && FLATMEM && (FSL_BOOKE || PPC_47x) -# help -# This builds a kernel image that is capable of running at the -# location the kernel is loaded at, without any alignment restrictions. -# -# One use is for the kexec on panic case where the recovery kernel -# must live at a different physical address than the primary -# kernel. -# -# Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address -# it has been loaded at and the compile time physical addresses -# CONFIG_PHYSICAL_START is ignored. However CONFIG_PHYSICAL_START -# setting can still be useful to bootwrappers that need to know the -# load location of the kernel (eg. u-boot/mkimage). + This option is overridden by CONFIG_RELOCATABLE + +config RELOCATABLE + bool "Build a relocatable kernel (EXPERIMENTAL)" + depends on EXPERIMENTAL && ADVANCED_OPTIONS && FLATMEM + select NONSTATIC_KERNEL + help + This builds a kernel image that is capable of running at the + location the kernel is loaded at, without any alignment restrictions. + This feature is a superset of DYNAMIC_MEMSTART and hence overrides it. + + One use is for the kexec on panic case where the recovery kernel + must live at a different physical address than the primary + kernel. + + Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address + it has been loaded at and the compile time physical addresses + CONFIG_PHYSICAL_START is ignored. However CONFIG_PHYSICAL_START + setting can still be useful to bootwrappers that need to know the + load address of the kernel (eg. u-boot/mkimage). + +config RELOCATABLE_PPC32 + def_bool y + depends on PPC32 && RELOCATABLE config PAGE_OFFSET_BOOL bool "Set custom page offset address" diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index ffe4d88f5a8..b8b105c01c6 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -63,9 +63,9 @@ override CC += -m$(CONFIG_WORD_SIZE) override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-powerpc $(AR) endif -LDFLAGS_vmlinux-yy := -Bstatic -LDFLAGS_vmlinux-$(CONFIG_PPC64)$(CONFIG_RELOCATABLE) := -pie -LDFLAGS_vmlinux := $(LDFLAGS_vmlinux-yy) +LDFLAGS_vmlinux-y := -Bstatic +LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie +LDFLAGS_vmlinux := $(LDFLAGS_vmlinux-y) CFLAGS-$(CONFIG_PPC64) := -mminimal-toc -mtraceback=no -mcall-aixdesc CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index ce4f7f17911..ee728e433aa 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -85,6 +85,8 @@ extra-$(CONFIG_FSL_BOOKE) := head_fsl_booke.o extra-$(CONFIG_8xx) := head_8xx.o extra-y += vmlinux.lds +obj-$(CONFIG_RELOCATABLE_PPC32) += reloc_32.o + obj-$(CONFIG_PPC32) += entry_32.o setup_32.o obj-$(CONFIG_PPC64) += dma-iommu.o iommu.o obj-$(CONFIG_KGDB) += kgdb.o diff --git a/arch/powerpc/kernel/reloc_32.S b/arch/powerpc/kernel/reloc_32.S new file mode 100644 index 00000000000..ef46ba6e094 --- /dev/null +++ b/arch/powerpc/kernel/reloc_32.S @@ -0,0 +1,208 @@ +/* + * Code to process dynamic relocations for PPC32. + * + * Copyrights (C) IBM Corporation, 2011. + * Author: Suzuki Poulose <suzuki@in.ibm.com> + * + * - Based on ppc64 code - reloc_64.S + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <asm/ppc_asm.h> + +/* Dynamic section table entry tags */ +DT_RELA = 7 /* Tag for Elf32_Rela section */ +DT_RELASZ = 8 /* Size of the Rela relocs */ +DT_RELAENT = 9 /* Size of one Rela reloc entry */ + +STN_UNDEF = 0 /* Undefined symbol index */ +STB_LOCAL = 0 /* Local binding for the symbol */ + +R_PPC_ADDR16_LO = 4 /* Lower half of (S+A) */ +R_PPC_ADDR16_HI = 5 /* Upper half of (S+A) */ +R_PPC_ADDR16_HA = 6 /* High Adjusted (S+A) */ +R_PPC_RELATIVE = 22 + +/* + * r3 = desired final address + */ + +_GLOBAL(relocate) + + mflr r0 /* Save our LR */ + bl 0f /* Find our current runtime address */ +0: mflr r12 /* Make it accessible */ + mtlr r0 + + lwz r11, (p_dyn - 0b)(r12) + add r11, r11, r12 /* runtime address of .dynamic section */ + lwz r9, (p_rela - 0b)(r12) + add r9, r9, r12 /* runtime address of .rela.dyn section */ + lwz r10, (p_st - 0b)(r12) + add r10, r10, r12 /* runtime address of _stext section */ + lwz r13, (p_sym - 0b)(r12) + add r13, r13, r12 /* runtime address of .dynsym section */ + + /* + * Scan the dynamic section for RELA, RELASZ entries + */ + li r6, 0 + li r7, 0 + li r8, 0 +1: lwz r5, 0(r11) /* ELF_Dyn.d_tag */ + cmpwi r5, 0 /* End of ELF_Dyn[] */ + beq eodyn + cmpwi r5, DT_RELA + bne relasz + lwz r7, 4(r11) /* r7 = rela.link */ + b skip +relasz: + cmpwi r5, DT_RELASZ + bne relaent + lwz r8, 4(r11) /* r8 = Total Rela relocs size */ + b skip +relaent: + cmpwi r5, DT_RELAENT + bne skip + lwz r6, 4(r11) /* r6 = Size of one Rela reloc */ +skip: + addi r11, r11, 8 + b 1b +eodyn: /* End of Dyn Table scan */ + + /* Check if we have found all the entries */ + cmpwi r7, 0 + beq done + cmpwi r8, 0 + beq done + cmpwi r6, 0 + beq done + + + /* + * Work out the current offset from the link time address of .rela + * section. + * cur_offset[r7] = rela.run[r9] - rela.link [r7] + * _stext.link[r12] = _stext.run[r10] - cur_offset[r7] + * final_offset[r3] = _stext.final[r3] - _stext.link[r12] + */ + subf r7, r7, r9 /* cur_offset */ + subf r12, r7, r10 + subf r3, r12, r3 /* final_offset */ + + subf r8, r6, r8 /* relaz -= relaent */ + /* + * Scan through the .rela table and process each entry + * r9 - points to the current .rela table entry + * r13 - points to the symbol table + */ + + /* + * Check if we have a relocation based on symbol + * r5 will hold the value of the symbol. + */ +applyrela: + lwz r4, 4(r9) /* r4 = rela.r_info */ + srwi r5, r4, 8 /* ELF32_R_SYM(r_info) */ + cmpwi r5, STN_UNDEF /* sym == STN_UNDEF ? */ + beq get_type /* value = 0 */ + /* Find the value of the symbol at index(r5) */ + slwi r5, r5, 4 /* r5 = r5 * sizeof(Elf32_Sym) */ + add r12, r13, r5 /* r12 = &__dyn_sym[Index] */ + + /* + * GNU ld has a bug, where dynamic relocs based on + * STB_LOCAL symbols, the value should be assumed + * to be zero. - Alan Modra + */ + /* XXX: Do we need to check if we are using GNU ld ? */ + lbz r5, 12(r12) /* r5 = dyn_sym[Index].st_info */ + extrwi r5, r5, 4, 24 /* r5 = ELF32_ST_BIND(r5) */ + cmpwi r5, STB_LOCAL /* st_value = 0, ld bug */ + beq get_type /* We have r5 = 0 */ + lwz r5, 4(r12) /* r5 = __dyn_sym[Index].st_value */ + +get_type: + /* Load the relocation type to r4 */ + extrwi r4, r4, 8, 24 /* r4 = ELF32_R_TYPE(r_info) = ((char*)r4)[3] */ + + /* R_PPC_RELATIVE */ + cmpwi r4, R_PPC_RELATIVE + bne hi16 + lwz r4, 0(r9) /* r_offset */ + lwz r0, 8(r9) /* r_addend */ + add r0, r0, r3 /* final addend */ + stwx r0, r4, r7 /* memory[r4+r7]) = (u32)r0 */ + b nxtrela /* continue */ + + /* R_PPC_ADDR16_HI */ +hi16: + cmpwi r4, R_PPC_ADDR16_HI + bne ha16 + lwz r4, 0(r9) /* r_offset */ + lwz r0, 8(r9) /* r_addend */ + add r0, r0, r3 + add r0, r0, r5 /* r0 = (S+A+Offset) */ + extrwi r0, r0, 16, 0 /* r0 = (r0 >> 16) */ + b store_half + + /* R_PPC_ADDR16_HA */ +ha16: + cmpwi r4, R_PPC_ADDR16_HA + bne lo16 + lwz r4, 0(r9) /* r_offset */ + lwz r0, 8(r9) /* r_addend */ + add r0, r0, r3 + add r0, r0, r5 /* r0 = (S+A+Offset) */ + extrwi r5, r0, 1, 16 /* Extract bit 16 */ + extrwi r0, r0, 16, 0 /* r0 = (r0 >> 16) */ + add r0, r0, r5 /* Add it to r0 */ + b store_half + + /* R_PPC_ADDR16_LO */ +lo16: + cmpwi r4, R_PPC_ADDR16_LO + bne nxtrela + lwz r4, 0(r9) /* r_offset */ + lwz r0, 8(r9) /* r_addend */ + add r0, r0, r3 + add r0, r0, r5 /* r0 = (S+A+Offset) */ + extrwi r0, r0, 16, 16 /* r0 &= 0xffff */ + /* Fall through to */ + + /* Store half word */ +store_half: + sthx r0, r4, r7 /* memory[r4+r7] = (u16)r0 */ + +nxtrela: + /* + * We have to flush the modified instructions to the + * main storage from the d-cache. And also, invalidate the + * cached instructions in i-cache which has been modified. + * + * We delay the sync / isync operation till the end, since + * we won't be executing the modified instructions until + * we return from here. + */ + dcbst r4,r7 + sync /* Ensure the data is flushed before icbi */ + icbi r4,r7 + cmpwi r8, 0 /* relasz = 0 ? */ + ble done + add r9, r9, r6 /* move to next entry in the .rela table */ + subf r8, r6, r8 /* relasz -= relaent */ + b applyrela + +done: + sync /* Wait for the flush to finish */ + isync /* Discard prefetched instructions */ + blr + +p_dyn: .long __dynamic_start - 0b +p_rela: .long __rela_dyn_start - 0b +p_sym: .long __dynamic_symtab - 0b +p_st: .long _stext - 0b diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 920276c0f6a..710a54005df 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -170,7 +170,13 @@ SECTIONS } #ifdef CONFIG_RELOCATABLE . = ALIGN(8); - .dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) { *(.dynsym) } + .dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) + { +#ifdef CONFIG_RELOCATABLE_PPC32 + __dynamic_symtab = .; +#endif + *(.dynsym) + } .dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) } .dynamic : AT(ADDR(.dynamic) - LOAD_OFFSET) { diff --git a/arch/powerpc/relocs_check.pl b/arch/powerpc/relocs_check.pl index d2571096c3e..7f5b8380886 100755 --- a/arch/powerpc/relocs_check.pl +++ b/arch/powerpc/relocs_check.pl @@ -32,8 +32,18 @@ while (<FD>) { next if (!/\s+R_/); # These relocations are okay - next if (/R_PPC64_RELATIVE/ or /R_PPC64_NONE/ or - /R_PPC64_ADDR64\s+mach_/); + # On PPC64: + # R_PPC64_RELATIVE, R_PPC64_NONE, R_PPC64_ADDR64 + # On PPC: + # R_PPC_RELATIVE, R_PPC_ADDR16_HI, + # R_PPC_ADDR16_HA,R_PPC_ADDR16_LO, + # R_PPC_NONE + + next if (/\bR_PPC64_RELATIVE\b/ or /\bR_PPC64_NONE\b/ or + /\bR_PPC64_ADDR64\s+mach_/); + next if (/\bR_PPC_ADDR16_LO\b/ or /\bR_PPC_ADDR16_HI\b/ or + /\bR_PPC_ADDR16_HA\b/ or /\bR_PPC_RELATIVE\b/ or + /\bR_PPC_NONE\b/); # If we see this type of relcoation it's an idication that # we /may/ be using an old version of binutils. |