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Diffstat (limited to 'arch/powerpc/kernel/head_64.S')
| -rw-r--r-- | arch/powerpc/kernel/head_64.S | 852 |
1 files changed, 852 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S new file mode 100644 index 000000000..d48125d0c --- /dev/null +++ b/arch/powerpc/kernel/head_64.S @@ -0,0 +1,852 @@ +/* + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP + * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> + * Adapted for Power Macintosh by Paul Mackerras. + * Low-level exception handlers and MMU support + * rewritten by Paul Mackerras. + * Copyright (C) 1996 Paul Mackerras. + * + * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and + * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com + * + * This file contains the entry point for the 64-bit kernel along + * with some early initialization code common to all 64-bit powerpc + * variants. + * + * 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 <linux/threads.h> +#include <linux/init.h> +#include <asm/reg.h> +#include <asm/page.h> +#include <asm/mmu.h> +#include <asm/ppc_asm.h> +#include <asm/asm-offsets.h> +#include <asm/bug.h> +#include <asm/cputable.h> +#include <asm/setup.h> +#include <asm/hvcall.h> +#include <asm/thread_info.h> +#include <asm/firmware.h> +#include <asm/page_64.h> +#include <asm/irqflags.h> +#include <asm/kvm_book3s_asm.h> +#include <asm/ptrace.h> +#include <asm/hw_irq.h> + +/* The physical memory is laid out such that the secondary processor + * spin code sits at 0x0000...0x00ff. On server, the vectors follow + * using the layout described in exceptions-64s.S + */ + +/* + * Entering into this code we make the following assumptions: + * + * For pSeries or server processors: + * 1. The MMU is off & open firmware is running in real mode. + * 2. The kernel is entered at __start + * -or- For OPAL entry: + * 1. The MMU is off, processor in HV mode, primary CPU enters at 0 + * with device-tree in gpr3. We also get OPAL base in r8 and + * entry in r9 for debugging purposes + * 2. Secondary processors enter at 0x60 with PIR in gpr3 + * + * For Book3E processors: + * 1. The MMU is on running in AS0 in a state defined in ePAPR + * 2. The kernel is entered at __start + */ + + .text + .globl _stext +_stext: +_GLOBAL(__start) + /* NOP this out unconditionally */ +BEGIN_FTR_SECTION + FIXUP_ENDIAN + b __start_initialization_multiplatform +END_FTR_SECTION(0, 1) + + /* Catch branch to 0 in real mode */ + trap + + /* Secondary processors spin on this value until it becomes non-zero. + * When non-zero, it contains the real address of the function the cpu + * should jump to. + */ + .balign 8 + .globl __secondary_hold_spinloop +__secondary_hold_spinloop: + .llong 0x0 + + /* Secondary processors write this value with their cpu # */ + /* after they enter the spin loop immediately below. */ + .globl __secondary_hold_acknowledge +__secondary_hold_acknowledge: + .llong 0x0 + +#ifdef CONFIG_RELOCATABLE + /* This flag is set to 1 by a loader if the kernel should run + * at the loaded address instead of the linked address. This + * is used by kexec-tools to keep the the kdump kernel in the + * crash_kernel region. The loader is responsible for + * observing the alignment requirement. + */ + /* Do not move this variable as kexec-tools knows about it. */ + . = 0x5c + .globl __run_at_load +__run_at_load: + .long 0x72756e30 /* "run0" -- relocate to 0 by default */ +#endif + + . = 0x60 +/* + * The following code is used to hold secondary processors + * in a spin loop after they have entered the kernel, but + * before the bulk of the kernel has been relocated. This code + * is relocated to physical address 0x60 before prom_init is run. + * All of it must fit below the first exception vector at 0x100. + * Use .globl here not _GLOBAL because we want __secondary_hold + * to be the actual text address, not a descriptor. + */ + .globl __secondary_hold +__secondary_hold: + FIXUP_ENDIAN +#ifndef CONFIG_PPC_BOOK3E + mfmsr r24 + ori r24,r24,MSR_RI + mtmsrd r24 /* RI on */ +#endif + /* Grab our physical cpu number */ + mr r24,r3 + /* stash r4 for book3e */ + mr r25,r4 + + /* Tell the master cpu we're here */ + /* Relocation is off & we are located at an address less */ + /* than 0x100, so only need to grab low order offset. */ + std r24,__secondary_hold_acknowledge-_stext(0) + sync + + li r26,0 +#ifdef CONFIG_PPC_BOOK3E + tovirt(r26,r26) +#endif + /* All secondary cpus wait here until told to start. */ +100: ld r12,__secondary_hold_spinloop-_stext(r26) + cmpdi 0,r12,0 + beq 100b + +#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC) +#ifdef CONFIG_PPC_BOOK3E + tovirt(r12,r12) +#endif + mtctr r12 + mr r3,r24 + /* + * it may be the case that other platforms have r4 right to + * begin with, this gives us some safety in case it is not + */ +#ifdef CONFIG_PPC_BOOK3E + mr r4,r25 +#else + li r4,0 +#endif + /* Make sure that patched code is visible */ + isync + bctr +#else + BUG_OPCODE +#endif + +/* This value is used to mark exception frames on the stack. */ + .section ".toc","aw" +exception_marker: + .tc ID_72656773_68657265[TC],0x7265677368657265 + .text + +/* + * On server, we include the exception vectors code here as it + * relies on absolute addressing which is only possible within + * this compilation unit + */ +#ifdef CONFIG_PPC_BOOK3S +#include "exceptions-64s.S" +#endif + +#ifdef CONFIG_PPC_BOOK3E +_GLOBAL(fsl_secondary_thread_init) + /* Enable branch prediction */ + lis r3,BUCSR_INIT@h + ori r3,r3,BUCSR_INIT@l + mtspr SPRN_BUCSR,r3 + isync + + /* + * Fix PIR to match the linear numbering in the device tree. + * + * On e6500, the reset value of PIR uses the low three bits for + * the thread within a core, and the upper bits for the core + * number. There are two threads per core, so shift everything + * but the low bit right by two bits so that the cpu numbering is + * continuous. + */ + mfspr r3, SPRN_PIR + rlwimi r3, r3, 30, 2, 30 + mtspr SPRN_PIR, r3 +#endif + +_GLOBAL(generic_secondary_thread_init) + mr r24,r3 + + /* turn on 64-bit mode */ + bl enable_64b_mode + + /* get a valid TOC pointer, wherever we're mapped at */ + bl relative_toc + tovirt(r2,r2) + +#ifdef CONFIG_PPC_BOOK3E + /* Book3E initialization */ + mr r3,r24 + bl book3e_secondary_thread_init +#endif + b generic_secondary_common_init + +/* + * On pSeries and most other platforms, secondary processors spin + * in the following code. + * At entry, r3 = this processor's number (physical cpu id) + * + * On Book3E, r4 = 1 to indicate that the initial TLB entry for + * this core already exists (setup via some other mechanism such + * as SCOM before entry). + */ +_GLOBAL(generic_secondary_smp_init) + FIXUP_ENDIAN + mr r24,r3 + mr r25,r4 + + /* turn on 64-bit mode */ + bl enable_64b_mode + + /* get a valid TOC pointer, wherever we're mapped at */ + bl relative_toc + tovirt(r2,r2) + +#ifdef CONFIG_PPC_BOOK3E + /* Book3E initialization */ + mr r3,r24 + mr r4,r25 + bl book3e_secondary_core_init +#endif + +generic_secondary_common_init: + /* Set up a paca value for this processor. Since we have the + * physical cpu id in r24, we need to search the pacas to find + * which logical id maps to our physical one. + */ + LOAD_REG_ADDR(r13, paca) /* Load paca pointer */ + ld r13,0(r13) /* Get base vaddr of paca array */ +#ifndef CONFIG_SMP + addi r13,r13,PACA_SIZE /* know r13 if used accidentally */ + b kexec_wait /* wait for next kernel if !SMP */ +#else + LOAD_REG_ADDR(r7, nr_cpu_ids) /* Load nr_cpu_ids address */ + lwz r7,0(r7) /* also the max paca allocated */ + li r5,0 /* logical cpu id */ +1: lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */ + cmpw r6,r24 /* Compare to our id */ + beq 2f + addi r13,r13,PACA_SIZE /* Loop to next PACA on miss */ + addi r5,r5,1 + cmpw r5,r7 /* Check if more pacas exist */ + blt 1b + + mr r3,r24 /* not found, copy phys to r3 */ + b kexec_wait /* next kernel might do better */ + +2: SET_PACA(r13) +#ifdef CONFIG_PPC_BOOK3E + addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */ + mtspr SPRN_SPRG_TLB_EXFRAME,r12 +#endif + + /* From now on, r24 is expected to be logical cpuid */ + mr r24,r5 + + /* See if we need to call a cpu state restore handler */ + LOAD_REG_ADDR(r23, cur_cpu_spec) + ld r23,0(r23) + ld r12,CPU_SPEC_RESTORE(r23) + cmpdi 0,r12,0 + beq 3f +#if !defined(_CALL_ELF) || _CALL_ELF != 2 + ld r12,0(r12) +#endif + mtctr r12 + bctrl + +3: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */ + lwarx r4,0,r3 + subi r4,r4,1 + stwcx. r4,0,r3 + bne 3b + isync + +4: HMT_LOW + lbz r23,PACAPROCSTART(r13) /* Test if this processor should */ + /* start. */ + cmpwi 0,r23,0 + beq 4b /* Loop until told to go */ + + sync /* order paca.run and cur_cpu_spec */ + isync /* In case code patching happened */ + + /* Create a temp kernel stack for use before relocation is on. */ + ld r1,PACAEMERGSP(r13) + subi r1,r1,STACK_FRAME_OVERHEAD + + b __secondary_start +#endif /* SMP */ + +/* + * Turn the MMU off. + * Assumes we're mapped EA == RA if the MMU is on. + */ +#ifdef CONFIG_PPC_BOOK3S +__mmu_off: + mfmsr r3 + andi. r0,r3,MSR_IR|MSR_DR + beqlr + mflr r4 + andc r3,r3,r0 + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r3 + sync + rfid + b . /* prevent speculative execution */ +#endif + + +/* + * Here is our main kernel entry point. We support currently 2 kind of entries + * depending on the value of r5. + * + * r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content + * in r3...r7 + * + * r5 == NULL -> kexec style entry. r3 is a physical pointer to the + * DT block, r4 is a physical pointer to the kernel itself + * + */ +__start_initialization_multiplatform: + /* Make sure we are running in 64 bits mode */ + bl enable_64b_mode + + /* Get TOC pointer (current runtime address) */ + bl relative_toc + + /* find out where we are now */ + bcl 20,31,$+4 +0: mflr r26 /* r26 = runtime addr here */ + addis r26,r26,(_stext - 0b)@ha + addi r26,r26,(_stext - 0b)@l /* current runtime base addr */ + + /* + * Are we booted from a PROM Of-type client-interface ? + */ + cmpldi cr0,r5,0 + beq 1f + b __boot_from_prom /* yes -> prom */ +1: + /* Save parameters */ + mr r31,r3 + mr r30,r4 +#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL + /* Save OPAL entry */ + mr r28,r8 + mr r29,r9 +#endif + +#ifdef CONFIG_PPC_BOOK3E + bl start_initialization_book3e + b __after_prom_start +#else + /* Setup some critical 970 SPRs before switching MMU off */ + mfspr r0,SPRN_PVR + srwi r0,r0,16 + cmpwi r0,0x39 /* 970 */ + beq 1f + cmpwi r0,0x3c /* 970FX */ + beq 1f + cmpwi r0,0x44 /* 970MP */ + beq 1f + cmpwi r0,0x45 /* 970GX */ + bne 2f +1: bl __cpu_preinit_ppc970 +2: + + /* Switch off MMU if not already off */ + bl __mmu_off + b __after_prom_start +#endif /* CONFIG_PPC_BOOK3E */ + +__boot_from_prom: +#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE + /* Save parameters */ + mr r31,r3 + mr r30,r4 + mr r29,r5 + mr r28,r6 + mr r27,r7 + + /* + * Align the stack to 16-byte boundary + * Depending on the size and layout of the ELF sections in the initial + * boot binary, the stack pointer may be unaligned on PowerMac + */ + 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 r5,r29 + mr r6,r28 + mr r7,r27 + + /* Do all of the interaction with OF client interface */ + mr r8,r26 + bl prom_init +#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */ + + /* We never return. We also hit that trap if trying to boot + * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */ + trap + +__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 + lwz r7,__run_at_load-_stext(r26) + cmplwi cr0,r7,1 /* flagged to stay where we are ? */ + bne 1f + add r25,r25,r26 +1: mr r3,r25 + bl relocate +#endif + +/* + * We need to run with _stext at physical address PHYSICAL_START. + * This will leave some code in the first 256B of + * real memory, which are reserved for software use. + * + * Note: This process overwrites the OF exception vectors. + */ + li r3,0 /* target addr */ +#ifdef CONFIG_PPC_BOOK3E + tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */ +#endif + mr. r4,r26 /* In some cases the loader may */ + beq 9f /* have already put us at zero */ + li r6,0x100 /* Start offset, the first 0x100 */ + /* bytes were copied earlier. */ +#ifdef CONFIG_PPC_BOOK3E + tovirt(r6,r6) /* on booke, we already run at PAGE_OFFSET */ +#endif + +#ifdef CONFIG_RELOCATABLE +/* + * Check if the kernel has to be running as relocatable kernel based on the + * variable __run_at_load, if it is set the kernel is treated as relocatable + * kernel, otherwise it will be moved to PHYSICAL_START + */ + lwz r7,__run_at_load-_stext(r26) + cmplwi cr0,r7,1 + bne 3f + + /* just copy interrupts */ + LOAD_REG_IMMEDIATE(r5, __end_interrupts - _stext) + b 5f +3: +#endif + lis r5,(copy_to_here - _stext)@ha + addi r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */ + + bl copy_and_flush /* copy the first n bytes */ + /* this includes the code being */ + /* executed here. */ + addis r8,r3,(4f - _stext)@ha /* Jump to the copy of this code */ + addi r12,r8,(4f - _stext)@l /* that we just made */ + mtctr r12 + bctr + +.balign 8 +p_end: .llong _end - _stext + +4: /* Now copy the rest of the kernel up to _end */ + addis r5,r26,(p_end - _stext)@ha + ld r5,(p_end - _stext)@l(r5) /* get _end */ +5: bl copy_and_flush /* copy the rest */ + +9: b start_here_multiplatform + +/* + * Copy routine used to copy the kernel to start at physical address 0 + * and flush and invalidate the caches as needed. + * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset + * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5. + * + * Note: this routine *only* clobbers r0, r6 and lr + */ +_GLOBAL(copy_and_flush) + addi r5,r5,-8 + addi r6,r6,-8 +4: li r0,8 /* Use the smallest common */ + /* denominator cache line */ + /* size. This results in */ + /* extra cache line flushes */ + /* but operation is correct. */ + /* Can't get cache line size */ + /* from NACA as it is being */ + /* moved too. */ + + mtctr r0 /* put # words/line in ctr */ +3: addi r6,r6,8 /* copy a cache line */ + ldx r0,r6,r4 + stdx r0,r6,r3 + bdnz 3b + dcbst r6,r3 /* write it to memory */ + sync + icbi r6,r3 /* flush the icache line */ + cmpld 0,r6,r5 + blt 4b + sync + addi r5,r5,8 + addi r6,r6,8 + isync + blr + +.align 8 +copy_to_here: + +#ifdef CONFIG_SMP +#ifdef CONFIG_PPC_PMAC +/* + * On PowerMac, secondary processors starts from the reset vector, which + * is temporarily turned into a call to one of the functions below. + */ + .section ".text"; + .align 2 ; + + .globl __secondary_start_pmac_0 +__secondary_start_pmac_0: + /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */ + li r24,0 + b 1f + li r24,1 + b 1f + li r24,2 + b 1f + li r24,3 +1: + +_GLOBAL(pmac_secondary_start) + /* turn on 64-bit mode */ + bl enable_64b_mode + + li r0,0 + mfspr r3,SPRN_HID4 + rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */ + sync + mtspr SPRN_HID4,r3 + isync + sync + slbia + + /* get TOC pointer (real address) */ + bl relative_toc + tovirt(r2,r2) + + /* Copy some CPU settings from CPU 0 */ + bl __restore_cpu_ppc970 + + /* pSeries do that early though I don't think we really need it */ + mfmsr r3 + ori r3,r3,MSR_RI + mtmsrd r3 /* RI on */ + + /* Set up a paca value for this processor. */ + LOAD_REG_ADDR(r4,paca) /* Load paca pointer */ + ld r4,0(r4) /* Get base vaddr of paca array */ + mulli r13,r24,PACA_SIZE /* Calculate vaddr of right paca */ + add r13,r13,r4 /* for this processor. */ + SET_PACA(r13) /* Save vaddr of paca in an SPRG*/ + + /* Mark interrupts soft and hard disabled (they might be enabled + * in the PACA when doing hotplug) + */ + li r0,0 + stb r0,PACASOFTIRQEN(r13) + li r0,PACA_IRQ_HARD_DIS + stb r0,PACAIRQHAPPENED(r13) + + /* Create a temp kernel stack for use before relocation is on. */ + ld r1,PACAEMERGSP(r13) + subi r1,r1,STACK_FRAME_OVERHEAD + + b __secondary_start + +#endif /* CONFIG_PPC_PMAC */ + +/* + * This function is called after the master CPU has released the + * secondary processors. The execution environment is relocation off. + * The paca for this processor has the following fields initialized at + * this point: + * 1. Processor number + * 2. Segment table pointer (virtual address) + * On entry the following are set: + * r1 = stack pointer (real addr of temp stack) + * r24 = cpu# (in Linux terms) + * r13 = paca virtual address + * SPRG_PACA = paca virtual address + */ + .section ".text"; + .align 2 ; + + .globl __secondary_start +__secondary_start: + /* Set thread priority to MEDIUM */ + HMT_MEDIUM + + /* Initialize the kernel stack */ + LOAD_REG_ADDR(r3, current_set) + sldi r28,r24,3 /* get current_set[cpu#] */ + ldx r14,r3,r28 + addi r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD + std r14,PACAKSAVE(r13) + + /* Do early setup for that CPU (SLB and hash table pointer) */ + bl early_setup_secondary + + /* + * setup the new stack pointer, but *don't* use this until + * translation is on. + */ + mr r1, r14 + + /* Clear backchain so we get nice backtraces */ + li r7,0 + mtlr r7 + + /* Mark interrupts soft and hard disabled (they might be enabled + * in the PACA when doing hotplug) + */ + stb r7,PACASOFTIRQEN(r13) + li r0,PACA_IRQ_HARD_DIS + stb r0,PACAIRQHAPPENED(r13) + + /* enable MMU and jump to start_secondary */ + LOAD_REG_ADDR(r3, start_secondary_prolog) + LOAD_REG_IMMEDIATE(r4, MSR_KERNEL) + + mtspr SPRN_SRR0,r3 + mtspr SPRN_SRR1,r4 + RFI + b . /* prevent speculative execution */ + +/* + * Running with relocation on at this point. All we want to do is + * zero the stack back-chain pointer and get the TOC virtual address + * before going into C code. + */ +start_secondary_prolog: + ld r2,PACATOC(r13) + li r3,0 + std r3,0(r1) /* Zero the stack frame pointer */ + bl start_secondary + b . +/* + * Reset stack pointer and call start_secondary + * to continue with online operation when woken up + * from cede in cpu offline. + */ +_GLOBAL(start_secondary_resume) + ld r1,PACAKSAVE(r13) /* Reload kernel stack pointer */ + li r3,0 + std r3,0(r1) /* Zero the stack frame pointer */ + bl start_secondary + b . +#endif + +/* + * This subroutine clobbers r11 and r12 + */ +enable_64b_mode: + mfmsr r11 /* grab the current MSR */ +#ifdef CONFIG_PPC_BOOK3E + oris r11,r11,0x8000 /* CM bit set, we'll set ICM later */ + mtmsr r11 +#else /* CONFIG_PPC_BOOK3E */ + li r12,(MSR_64BIT | MSR_ISF)@highest + sldi r12,r12,48 + or r11,r11,r12 + mtmsrd r11 + isync +#endif + blr + +/* + * This puts the TOC pointer into r2, offset by 0x8000 (as expected + * by the toolchain). It computes the correct value for wherever we + * are running at the moment, using position-independent code. + * + * Note: The compiler constructs pointers using offsets from the + * TOC in -mcmodel=medium mode. After we relocate to 0 but before + * the MMU is on we need our TOC to be a virtual address otherwise + * these pointers will be real addresses which may get stored and + * accessed later with the MMU on. We use tovirt() at the call + * sites to handle this. + */ +_GLOBAL(relative_toc) + mflr r0 + bcl 20,31,$+4 +0: mflr r11 + ld r2,(p_toc - 0b)(r11) + add r2,r2,r11 + mtlr r0 + blr + +.balign 8 +p_toc: .llong __toc_start + 0x8000 - 0b + +/* + * This is where the main kernel code starts. + */ +start_here_multiplatform: + /* set up the TOC */ + bl relative_toc + tovirt(r2,r2) + + /* Clear out the BSS. It may have been done in prom_init, + * already but that's irrelevant since prom_init will soon + * be detached from the kernel completely. Besides, we need + * to clear it now for kexec-style entry. + */ + LOAD_REG_ADDR(r11,__bss_stop) + LOAD_REG_ADDR(r8,__bss_start) + sub r11,r11,r8 /* bss size */ + addi r11,r11,7 /* round up to an even double word */ + srdi. r11,r11,3 /* shift right by 3 */ + beq 4f + addi r8,r8,-8 + li r0,0 + mtctr r11 /* zero this many doublewords */ +3: stdu r0,8(r8) + bdnz 3b +4: + +#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL + /* Setup OPAL entry */ + LOAD_REG_ADDR(r11, opal) + std r28,0(r11); + std r29,8(r11); +#endif + +#ifndef CONFIG_PPC_BOOK3E + mfmsr r6 + ori r6,r6,MSR_RI + mtmsrd r6 /* RI on */ +#endif + +#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 */ + /* up the htab. This is done because we have relocated the */ + /* kernel but are still running in real mode. */ + + LOAD_REG_ADDR(r3,init_thread_union) + + /* set up a stack pointer */ + addi r1,r3,THREAD_SIZE + li r0,0 + stdu r0,-STACK_FRAME_OVERHEAD(r1) + + /* + * Do very early kernel initializations, including initial hash table + * and SLB setup before we turn on relocation. + */ + + /* Restore parameters passed from prom_init/kexec */ + mr r3,r31 + bl early_setup /* also sets r13 and SPRG_PACA */ + + LOAD_REG_ADDR(r3, start_here_common) + ld r4,PACAKMSR(r13) + mtspr SPRN_SRR0,r3 + mtspr SPRN_SRR1,r4 + RFI + b . /* prevent speculative execution */ + + /* This is where all platforms converge execution */ + +start_here_common: + /* relocation is on at this point */ + std r1,PACAKSAVE(r13) + + /* Load the TOC (virtual address) */ + ld r2,PACATOC(r13) + + /* Do more system initializations in virtual mode */ + bl setup_system + + /* Mark interrupts soft and hard disabled (they might be enabled + * in the PACA when doing hotplug) + */ + li r0,0 + stb r0,PACASOFTIRQEN(r13) + li r0,PACA_IRQ_HARD_DIS + stb r0,PACAIRQHAPPENED(r13) + + /* Generic kernel entry */ + bl start_kernel + + /* Not reached */ + BUG_OPCODE + +/* + * We put a few things here that have to be page-aligned. + * This stuff goes at the beginning of the bss, which is page-aligned. + */ + .section ".bss" + + .align PAGE_SHIFT + + .globl empty_zero_page +empty_zero_page: + .space PAGE_SIZE + + .globl swapper_pg_dir +swapper_pg_dir: + .space PGD_TABLE_SIZE |