endmenu
if PPC64
+config RELOCATABLE
+ bool "Build a relocatable kernel"
+ help
+ This builds a kernel image that is capable of running anywhere
+ in the RMA (real memory area) at any 16k-aligned base address.
+ The kernel is linked as a position-independent executable (PIE)
+ and contains dynamic relocations which are processed early
+ in the bootup process.
+
+ One use is for the kexec on panic case where the recovery kernel
+ must live at a different physical address than the primary
+ kernel.
+
config PAGE_OFFSET
hex
default "0xc000000000000000"
override AR := GNUTARGET=elf$(CONFIG_WORD_SIZE)-powerpc $(AR)
endif
-LDFLAGS_vmlinux := -Bstatic
+LDFLAGS_vmlinux-yy := -Bstatic
+LDFLAGS_vmlinux-$(CONFIG_PPC64)$(CONFIG_RELOCATABLE) := -pie
+LDFLAGS_vmlinux := $(LDFLAGS_vmlinux-yy)
CFLAGS-$(CONFIG_PPC64) := -mminimal-toc -mtraceback=none -mcall-aixdesc
CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 -mmultiple
$(obj)/vmlinux.strip: vmlinux
$(STRIP) -s -R .comment $< -o $@
+# The iseries hypervisor won't take an ET_DYN executable, so this
+# changes the type (byte 17) in the file to ET_EXEC (2).
$(obj)/zImage.iseries: vmlinux
$(STRIP) -s -R .comment $< -o $@
+ printf "\x02" | dd of=$@ conv=notrunc bs=1 seek=17
$(obj)/uImage: vmlinux $(wrapperbits)
$(call if_changed,wrap,uboot)
elf64->e_ident[EI_MAG3] == ELFMAG3 &&
elf64->e_ident[EI_CLASS] == ELFCLASS64 &&
elf64->e_ident[EI_DATA] == ELFDATA2MSB &&
- elf64->e_type == ET_EXEC &&
+ (elf64->e_type == ET_EXEC ||
+ elf64->e_type == ET_DYN) &&
elf64->e_machine == EM_PPC64))
return 0;
elf32->e_ident[EI_MAG3] == ELFMAG3 &&
elf32->e_ident[EI_CLASS] == ELFCLASS32 &&
elf32->e_ident[EI_DATA] == ELFDATA2MSB &&
- elf32->e_type == ET_EXEC &&
+ (elf32->e_type == ET_EXEC ||
+ elf32->e_type == ET_DYN) &&
elf32->e_machine == EM_PPC))
return 0;
})
#endif /* 1 */
-/* This is only valid for addresses >= KERNELBASE */
+/* This is only valid for addresses >= PAGE_OFFSET */
static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
{
if (ssize == MMU_SEGSIZE_256M)
#define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
-#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_FLATMEM)
+#if defined(CONFIG_RELOCATABLE)
#ifndef __ASSEMBLY__
extern phys_addr_t memstart_addr;
extern phys_addr_t kernstart_addr;
#endif
#define PHYSICAL_START kernstart_addr
-#define MEMORY_START memstart_addr
#else
#define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
+#endif
+
+#ifdef CONFIG_PPC64
+#define MEMORY_START 0UL
+#elif defined(CONFIG_RELOCATABLE)
+#define MEMORY_START memstart_addr
+#else
#define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
#endif
#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) - PHYSICAL_START + KERNELBASE))
-#define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
+#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
+#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
/*
* Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
return 0;
}
+static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
+{
+ return start < (unsigned long)__init_end &&
+ (unsigned long)_stext < end;
+}
+
#undef dereference_function_descriptor
void *dereference_function_descriptor(void *);
paca.o cpu_setup_ppc970.o \
cpu_setup_pa6t.o \
firmware.o nvram_64.o
+obj64-$(CONFIG_RELOCATABLE) += reloc_64.o
obj-$(CONFIG_PPC64) += vdso64/
obj-$(CONFIG_ALTIVEC) += vecemu.o vector.o
obj-$(CONFIG_PPC_970_NAP) += idle_power4.o
*/
rldicr r1,r1,0,59
+#ifdef CONFIG_RELOCATABLE
+ /* Relocate code for where we are now */
+ mr r3,r26
+ bl .relocate
+#endif
+
/* Restore parameters */
mr r3,r31
mr r4,r30
mr r7,r27
/* Do all of the interaction with OF client interface */
+ mr r8,r26
bl .prom_init
/* We never return */
trap
_STATIC(__after_prom_start)
+#ifdef CONFIG_RELOCATABLE
+ /* process relocations for the final address of the kernel */
+ lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
+ sldi r25,r25,32
+ mr r3,r25
+ bl .relocate
+#endif
/*
* We need to run with _stext at physical address PHYSICAL_START.
*
* Note: This process overwrites the OF exception vectors.
*/
- LOAD_REG_IMMEDIATE(r3, PHYSICAL_START) /* target addr */
- cmpd r3,r26 /* In some cases the loader may */
+ li r3,0 /* target addr */
+ mr. r4,r26 /* In some cases the loader may */
beq 9f /* have already put us at zero */
- mr r4,r26 /* source address */
lis r5,(copy_to_here - _stext)@ha
addi r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
li r6,0x100 /* Start offset, the first 0x100 */
ori r6,r6,MSR_RI
mtmsrd r6 /* RI on */
+#ifdef CONFIG_RELOCATABLE
+ /* Save the physical address we're running at in kernstart_addr */
+ LOAD_REG_ADDR(r4, kernstart_addr)
+ clrldi r0,r25,2
+ std r0,0(r4)
+#endif
+
/* The following gets the stack set up with the regs */
/* pointing to the real addr of the kernel stack. This is */
/* all done to support the C function call below which sets */
#include <asm/lppaca.h>
#include <asm/paca.h>
+#include <asm/sections.h>
/* This symbol is provided by the linker - let it fill in the paca
* field correctly */
new_paca->lock_token = 0x8000;
new_paca->paca_index = cpu;
new_paca->kernel_toc = kernel_toc;
- new_paca->kernelbase = KERNELBASE;
+ new_paca->kernelbase = (unsigned long) _stext;
new_paca->kernel_msr = MSR_KERNEL;
new_paca->hw_cpu_id = 0xffff;
new_paca->slb_shadow_ptr = &slb_shadow[cpu];
/* Reserve LMB regions used by kernel, initrd, dt, etc... */
lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
+ /* If relocatable, reserve first 32k for interrupt vectors etc. */
+ if (PHYSICAL_START > MEMORY_START)
+ lmb_reserve(MEMORY_START, 0x8000);
reserve_kdump_trampoline();
reserve_crashkernel();
early_reserve_mem();
unsigned long __init prom_init(unsigned long r3, unsigned long r4,
unsigned long pp,
- unsigned long r6, unsigned long r7)
+ unsigned long r6, unsigned long r7,
+ unsigned long kbase)
{
struct prom_t *_prom;
unsigned long hdr;
- unsigned long offset = reloc_offset();
#ifdef CONFIG_PPC32
+ unsigned long offset = reloc_offset();
reloc_got2(offset);
#endif
*/
RELOC(of_platform) = prom_find_machine_type();
+#ifndef CONFIG_RELOCATABLE
/* Bail if this is a kdump kernel. */
if (PHYSICAL_START > 0)
prom_panic("Error: You can't boot a kdump kernel from OF!\n");
+#endif
/*
* Check for an initrd
* Copy the CPU hold code
*/
if (RELOC(of_platform) != PLATFORM_POWERMAC)
- copy_and_flush(0, KERNELBASE + offset, 0x100, 0);
+ copy_and_flush(0, kbase, 0x100, 0);
/*
* Do early parsing of command line
reloc_got2(-offset);
#endif
- __start(hdr, KERNELBASE + offset, 0);
+ __start(hdr, kbase, 0);
return 0;
}
--- /dev/null
+/*
+ * Code to process dynamic relocations in the kernel.
+ *
+ * Copyright 2008 Paul Mackerras, IBM Corp.
+ *
+ * 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>
+
+RELA = 7
+RELACOUNT = 0x6ffffff9
+R_PPC64_RELATIVE = 22
+
+/*
+ * r3 = desired final address of kernel
+ */
+_GLOBAL(relocate)
+ mflr r0
+ bcl 20,31,$+4
+0: mflr r12 /* r12 has runtime addr of label 0 */
+ mtlr r0
+ ld r11,(p_dyn - 0b)(r12)
+ add r11,r11,r12 /* r11 has runtime addr of .dynamic section */
+ ld r9,(p_rela - 0b)(r12)
+ add r9,r9,r12 /* r9 has runtime addr of .rela.dyn section */
+ ld r10,(p_st - 0b)(r12)
+ add r10,r10,r12 /* r10 has runtime addr of _stext */
+
+ /*
+ * Scan the dynamic section for the RELA and RELACOUNT entries.
+ */
+ li r7,0
+ li r8,0
+1: ld r6,0(r11) /* get tag */
+ cmpdi r6,0
+ beq 4f /* end of list */
+ cmpdi r6,RELA
+ bne 2f
+ ld r7,8(r11) /* get RELA pointer in r7 */
+ b 3f
+2: addis r6,r6,(-RELACOUNT)@ha
+ cmpdi r6,RELACOUNT@l
+ bne 3f
+ ld r8,8(r11) /* get RELACOUNT value in r8 */
+3: addi r11,r11,16
+ b 1b
+4: cmpdi r7,0 /* check we have both RELA and RELACOUNT */
+ cmpdi cr1,r8,0
+ beq 6f
+ beq cr1,6f
+
+ /*
+ * Work out linktime address of _stext and hence the
+ * relocation offset to be applied.
+ * cur_offset [r7] = rela.run [r9] - rela.link [r7]
+ * _stext.link [r10] = _stext.run [r10] - cur_offset [r7]
+ * final_offset [r3] = _stext.final [r3] - _stext.link [r10]
+ */
+ subf r7,r7,r9 /* cur_offset */
+ subf r10,r7,r10
+ subf r3,r10,r3 /* final_offset */
+
+ /*
+ * Run through the list of relocations and process the
+ * R_PPC64_RELATIVE ones.
+ */
+ mtctr r8
+5: lwz r0,12(9) /* ELF64_R_TYPE(reloc->r_info) */
+ cmpwi r0,R_PPC64_RELATIVE
+ bne 6f
+ ld r6,0(r9) /* reloc->r_offset */
+ ld r0,16(r9) /* reloc->r_addend */
+ add r0,r0,r3
+ stdx r0,r7,r6
+ addi r9,r9,24
+ bdnz 5b
+
+6: blr
+
+p_dyn: .llong __dynamic_start - 0b
+p_rela: .llong __rela_dyn_start - 0b
+p_st: .llong _stext - 0b
+
*(.machine.desc)
__machine_desc_end = . ;
}
+ . = ALIGN(8);
+ .dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) { *(.dynsym) }
+ .dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) }
+ .dynamic : AT(ADDR(.dynamic) - LOAD_OFFSET)
+ {
+ __dynamic_start = .;
+ *(.dynamic)
+ }
+ .hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) }
+ .interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) }
+ .rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET)
+ {
+ __rela_dyn_start = .;
+ *(.rela*)
+ }
/* freed after init ends here */
. = ALIGN(PAGE_SIZE);
unsigned long tprot = prot;
/* Make kernel text executable */
- if (in_kernel_text(vaddr))
+ if (overlaps_kernel_text(vaddr, vaddr + step))
tprot &= ~HPTE_R_N;
hash = hpt_hash(va, shift, ssize);
{
unsigned int save_vector;
unsigned long target, flags;
- unsigned int *vector = (unsigned int *)(KERNELBASE+0x100);
+ unsigned int *vector = (unsigned int *)(PAGE_OFFSET+0x100);
if (nr < 0 || nr > 3)
return;
save_vector = *vector;
/* Setup fake reset vector that does
- * b __secondary_start_pmac_0 + nr*8 - KERNELBASE
+ * b __secondary_start_pmac_0 + nr*8
*/
target = (unsigned long) __secondary_start_pmac_0 + nr * 8;
patch_branch(vector, target, BRANCH_SET_LINK);
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff