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-rw-r--r--arch/powerpc/Kconfig41
-rw-r--r--arch/powerpc/Makefile6
-rw-r--r--arch/powerpc/kernel/Makefile2
-rw-r--r--arch/powerpc/kernel/reloc_32.S208
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S8
-rwxr-xr-xarch/powerpc/relocs_check.pl14
6 files changed, 256 insertions, 23 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8b323b7b0a61..2ad5ea827820 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 ffe4d88f5a8a..b8b105c01c64 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-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index ce4f7f179117..ee728e433aa2 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -85,6 +85,8 @@ extra-$(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 000000000000..ef46ba6e094f
--- /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 920276c0f6a1..710a54005dfb 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 d2571096c3e9..7f5b83808862 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.

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