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Diffstat (limited to 'arch/powerpc/cpu/mpc8220/start.S')
| -rw-r--r-- | arch/powerpc/cpu/mpc8220/start.S | 750 |
1 files changed, 750 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc8220/start.S b/arch/powerpc/cpu/mpc8220/start.S new file mode 100644 index 0000000..3d79d8e --- /dev/null +++ b/arch/powerpc/cpu/mpc8220/start.S @@ -0,0 +1,750 @@ +/* + * Copyright (C) 1998 Dan Malek <dmalek@jlc.net> + * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> + * Copyright (C) 2000 - 2003 Wolfgang Denk <wd@denx.de> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* + * U-Boot - Startup Code for MPC8220 CPUs + */ +#include <config.h> +#include <mpc8220.h> +#include <timestamp.h> +#include <version.h> + +#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */ + +#include <ppc_asm.tmpl> +#include <ppc_defs.h> + +#include <asm/cache.h> +#include <asm/mmu.h> + +#ifndef CONFIG_IDENT_STRING +#define CONFIG_IDENT_STRING "" +#endif + +/* We don't want the MMU yet. +*/ +#undef MSR_KERNEL +/* Floating Point enable, Machine Check and Recoverable Interr. */ +#ifdef DEBUG +#define MSR_KERNEL (MSR_FP|MSR_RI) +#else +#define MSR_KERNEL (MSR_FP|MSR_ME|MSR_RI) +#endif + +/* + * Set up GOT: Global Offset Table + * + * Use r12 to access the GOT + */ + START_GOT + GOT_ENTRY(_GOT2_TABLE_) + GOT_ENTRY(_FIXUP_TABLE_) + + GOT_ENTRY(_start) + GOT_ENTRY(_start_of_vectors) + GOT_ENTRY(_end_of_vectors) + GOT_ENTRY(transfer_to_handler) + + GOT_ENTRY(__init_end) + GOT_ENTRY(_end) + GOT_ENTRY(__bss_start) + END_GOT + +/* + * Version string + */ + .data + .globl version_string +version_string: + .ascii U_BOOT_VERSION + .ascii " (", U_BOOT_DATE, " - ", U_BOOT_TIME, ")" + .ascii CONFIG_IDENT_STRING, "\0" + +/* + * Exception vectors + */ + .text + . = EXC_OFF_SYS_RESET + .globl _start +_start: + li r21, BOOTFLAG_COLD /* Normal Power-On */ + nop + b boot_cold + + . = EXC_OFF_SYS_RESET + 0x10 + + .globl _start_warm +_start_warm: + li r21, BOOTFLAG_WARM /* Software reboot */ + b boot_warm + +boot_cold: +boot_warm: + mfmsr r5 /* save msr contents */ + + /* replace default MBAR base address from 0x80000000 + to 0xf0000000 */ + +#if defined(CONFIG_SYS_DEFAULT_MBAR) && !defined(CONFIG_SYS_RAMBOOT) + lis r3, CONFIG_SYS_MBAR@h + ori r3, r3, CONFIG_SYS_MBAR@l + + /* MBAR is mirrored into the MBAR SPR */ + mtspr MBAR,r3 + mtspr SPRN_SPRG7W,r3 + lis r4, CONFIG_SYS_DEFAULT_MBAR@h + stw r3, 0(r4) +#endif /* CONFIG_SYS_DEFAULT_MBAR */ + + /* Initialise the MPC8220 processor core */ + /*--------------------------------------------------------------*/ + + bl init_8220_core + + /* initialize some things that are hard to access from C */ + /*--------------------------------------------------------------*/ + + /* set up stack in on-chip SRAM */ + lis r3, CONFIG_SYS_INIT_RAM_ADDR@h + ori r3, r3, CONFIG_SYS_INIT_RAM_ADDR@l + ori r1, r3, CONFIG_SYS_INIT_SP_OFFSET + + li r0, 0 /* Make room for stack frame header and */ + stwu r0, -4(r1) /* clear final stack frame so that */ + stwu r0, -4(r1) /* stack backtraces terminate cleanly */ + + /* let the C-code set up the rest */ + /* */ + /* Be careful to keep code relocatable ! */ + /*--------------------------------------------------------------*/ + + GET_GOT /* initialize GOT access */ + + /* r3: IMMR */ + bl cpu_init_f /* run low-level CPU init code (in Flash)*/ + + mr r3, r21 + /* r3: BOOTFLAG */ + bl board_init_f /* run 1st part of board init code (in Flash)*/ + +/* + * Vector Table + */ + + .globl _start_of_vectors +_start_of_vectors: + +/* Machine check */ + STD_EXCEPTION(0x200, MachineCheck, MachineCheckException) + +/* Data Storage exception. */ + STD_EXCEPTION(0x300, DataStorage, UnknownException) + +/* Instruction Storage exception. */ + STD_EXCEPTION(0x400, InstStorage, UnknownException) + +/* External Interrupt exception. */ + STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt) + +/* Alignment exception. */ + . = 0x600 +Alignment: + EXCEPTION_PROLOG(SRR0, SRR1) + mfspr r4,DAR + stw r4,_DAR(r21) + mfspr r5,DSISR + stw r5,_DSISR(r21) + addi r3,r1,STACK_FRAME_OVERHEAD + EXC_XFER_TEMPLATE(Alignment, AlignmentException, MSR_KERNEL, COPY_EE) + +/* Program check exception */ + . = 0x700 +ProgramCheck: + EXCEPTION_PROLOG(SRR0, SRR1) + addi r3,r1,STACK_FRAME_OVERHEAD + EXC_XFER_TEMPLATE(ProgramCheck, ProgramCheckException, + MSR_KERNEL, COPY_EE) + + STD_EXCEPTION(0x800, FPUnavailable, UnknownException) + + /* I guess we could implement decrementer, and may have + * to someday for timekeeping. + */ + STD_EXCEPTION(0x900, Decrementer, timer_interrupt) + + STD_EXCEPTION(0xa00, Trap_0a, UnknownException) + STD_EXCEPTION(0xb00, Trap_0b, UnknownException) + STD_EXCEPTION(0xc00, SystemCall, UnknownException) + STD_EXCEPTION(0xd00, SingleStep, UnknownException) + + STD_EXCEPTION(0xe00, Trap_0e, UnknownException) + STD_EXCEPTION(0xf00, Trap_0f, UnknownException) + + STD_EXCEPTION(0x1000, InstructionTLBMiss, UnknownException) + STD_EXCEPTION(0x1100, DataLoadTLBMiss, UnknownException) + STD_EXCEPTION(0x1200, DataStoreTLBMiss, UnknownException) +#ifdef DEBUG + . = 0x1300 + /* + * This exception occurs when the program counter matches the + * Instruction Address Breakpoint Register (IABR). + * + * I want the cpu to halt if this occurs so I can hunt around + * with the debugger and look at things. + * + * When DEBUG is defined, both machine check enable (in the MSR) + * and checkstop reset enable (in the reset mode register) are + * turned off and so a checkstop condition will result in the cpu + * halting. + * + * I force the cpu into a checkstop condition by putting an illegal + * instruction here (at least this is the theory). + * + * well - that didnt work, so just do an infinite loop! + */ +1: b 1b +#else + STD_EXCEPTION(0x1300, InstructionBreakpoint, DebugException) +#endif + STD_EXCEPTION(0x1400, SMI, UnknownException) + + STD_EXCEPTION(0x1500, Trap_15, UnknownException) + STD_EXCEPTION(0x1600, Trap_16, UnknownException) + STD_EXCEPTION(0x1700, Trap_17, UnknownException) + STD_EXCEPTION(0x1800, Trap_18, UnknownException) + STD_EXCEPTION(0x1900, Trap_19, UnknownException) + STD_EXCEPTION(0x1a00, Trap_1a, UnknownException) + STD_EXCEPTION(0x1b00, Trap_1b, UnknownException) + STD_EXCEPTION(0x1c00, Trap_1c, UnknownException) + STD_EXCEPTION(0x1d00, Trap_1d, UnknownException) + STD_EXCEPTION(0x1e00, Trap_1e, UnknownException) + STD_EXCEPTION(0x1f00, Trap_1f, UnknownException) + STD_EXCEPTION(0x2000, Trap_20, UnknownException) + STD_EXCEPTION(0x2100, Trap_21, UnknownException) + STD_EXCEPTION(0x2200, Trap_22, UnknownException) + STD_EXCEPTION(0x2300, Trap_23, UnknownException) + STD_EXCEPTION(0x2400, Trap_24, UnknownException) + STD_EXCEPTION(0x2500, Trap_25, UnknownException) + STD_EXCEPTION(0x2600, Trap_26, UnknownException) + STD_EXCEPTION(0x2700, Trap_27, UnknownException) + STD_EXCEPTION(0x2800, Trap_28, UnknownException) + STD_EXCEPTION(0x2900, Trap_29, UnknownException) + STD_EXCEPTION(0x2a00, Trap_2a, UnknownException) + STD_EXCEPTION(0x2b00, Trap_2b, UnknownException) + STD_EXCEPTION(0x2c00, Trap_2c, UnknownException) + STD_EXCEPTION(0x2d00, Trap_2d, UnknownException) + STD_EXCEPTION(0x2e00, Trap_2e, UnknownException) + STD_EXCEPTION(0x2f00, Trap_2f, UnknownException) + + + .globl _end_of_vectors +_end_of_vectors: + + . = 0x3000 + +/* + * This code finishes saving the registers to the exception frame + * and jumps to the appropriate handler for the exception. + * Register r21 is pointer into trap frame, r1 has new stack pointer. + */ + .globl transfer_to_handler +transfer_to_handler: + stw r22,_NIP(r21) + lis r22,MSR_POW@h + andc r23,r23,r22 + stw r23,_MSR(r21) + SAVE_GPR(7, r21) + SAVE_4GPRS(8, r21) + SAVE_8GPRS(12, r21) + SAVE_8GPRS(24, r21) + mflr r23 + andi. r24,r23,0x3f00 /* get vector offset */ + stw r24,TRAP(r21) + li r22,0 + stw r22,RESULT(r21) + lwz r24,0(r23) /* virtual address of handler */ + lwz r23,4(r23) /* where to go when done */ + mtspr SRR0,r24 + mtspr SRR1,r20 + mtlr r23 + SYNC + rfi /* jump to handler, enable MMU */ + +int_return: + mfmsr r28 /* Disable interrupts */ + li r4,0 + ori r4,r4,MSR_EE + andc r28,r28,r4 + SYNC /* Some chip revs need this... */ + mtmsr r28 + SYNC + lwz r2,_CTR(r1) + lwz r0,_LINK(r1) + mtctr r2 + mtlr r0 + lwz r2,_XER(r1) + lwz r0,_CCR(r1) + mtspr XER,r2 + mtcrf 0xFF,r0 + REST_10GPRS(3, r1) + REST_10GPRS(13, r1) + REST_8GPRS(23, r1) + REST_GPR(31, r1) + lwz r2,_NIP(r1) /* Restore environment */ + lwz r0,_MSR(r1) + mtspr SRR0,r2 + mtspr SRR1,r0 + lwz r0,GPR0(r1) + lwz r2,GPR2(r1) + lwz r1,GPR1(r1) + SYNC + rfi + +/* + * This code initialises the MPC8220 processor core + * (conforms to PowerPC 603e spec) + * Note: expects original MSR contents to be in r5. + */ + + .globl init_8220_core +init_8220_core: + + /* Initialize machine status; enable machine check interrupt */ + /*--------------------------------------------------------------*/ + + li r3, MSR_KERNEL /* Set ME and RI flags */ + rlwimi r3, r5, 0, 25, 25 /* preserve IP bit set by HRCW */ +#ifdef DEBUG + rlwimi r3, r5, 0, 21, 22 /* debugger might set SE & BE bits */ +#endif + SYNC /* Some chip revs need this... */ + mtmsr r3 + SYNC + mtspr SRR1, r3 /* Make SRR1 match MSR */ + + /* Initialize the Hardware Implementation-dependent Registers */ + /* HID0 also contains cache control */ + /*--------------------------------------------------------------*/ + + lis r3, CONFIG_SYS_HID0_INIT@h + ori r3, r3, CONFIG_SYS_HID0_INIT@l + SYNC + mtspr HID0, r3 + + lis r3, CONFIG_SYS_HID0_FINAL@h + ori r3, r3, CONFIG_SYS_HID0_FINAL@l + SYNC + mtspr HID0, r3 + + /* Enable Extra BATs */ + mfspr r3, 1011 /* HID2 */ + lis r4, 0x0004 + ori r4, r4, 0x0000 + or r4, r4, r3 + mtspr 1011, r4 + sync + + /* clear all BAT's */ + /*--------------------------------------------------------------*/ + + li r0, 0 + mtspr DBAT0U, r0 + mtspr DBAT0L, r0 + mtspr DBAT1U, r0 + mtspr DBAT1L, r0 + mtspr DBAT2U, r0 + mtspr DBAT2L, r0 + mtspr DBAT3U, r0 + mtspr DBAT3L, r0 + mtspr DBAT4U, r0 + mtspr DBAT4L, r0 + mtspr DBAT5U, r0 + mtspr DBAT5L, r0 + mtspr DBAT6U, r0 + mtspr DBAT6L, r0 + mtspr DBAT7U, r0 + mtspr DBAT7L, r0 + mtspr IBAT0U, r0 + mtspr IBAT0L, r0 + mtspr IBAT1U, r0 + mtspr IBAT1L, r0 + mtspr IBAT2U, r0 + mtspr IBAT2L, r0 + mtspr IBAT3U, r0 + mtspr IBAT3L, r0 + mtspr IBAT4U, r0 + mtspr IBAT4L, r0 + mtspr IBAT5U, r0 + mtspr IBAT5L, r0 + mtspr IBAT6U, r0 + mtspr IBAT6L, r0 + mtspr IBAT7U, r0 + mtspr IBAT7L, r0 + SYNC + + /* invalidate all tlb's */ + /* */ + /* From the 603e User Manual: "The 603e provides the ability to */ + /* invalidate a TLB entry. The TLB Invalidate Entry (tlbie) */ + /* instruction invalidates the TLB entry indexed by the EA, and */ + /* operates on both the instruction and data TLBs simultaneously*/ + /* invalidating four TLB entries (both sets in each TLB). The */ + /* index corresponds to bits 15-19 of the EA. To invalidate all */ + /* entries within both TLBs, 32 tlbie instructions should be */ + /* issued, incrementing this field by one each time." */ + /* */ + /* "Note that the tlbia instruction is not implemented on the */ + /* 603e." */ + /* */ + /* bits 15-19 correspond to addresses 0x00000000 to 0x0001F000 */ + /* incrementing by 0x1000 each time. The code below is sort of */ + /* based on code in "flush_tlbs" from arch/powerpc/kernel/head.S */ + /* */ + /*--------------------------------------------------------------*/ + + li r3, 32 + mtctr r3 + li r3, 0 +1: tlbie r3 + addi r3, r3, 0x1000 + bdnz 1b + SYNC + + /* Done! */ + /*--------------------------------------------------------------*/ + + blr + +/* Cache functions. + * + * Note: requires that all cache bits in + * HID0 are in the low half word. + */ + .globl icache_enable +icache_enable: + lis r4, 0 + ori r4, r4, CONFIG_SYS_HID0_INIT /* set ICE & ICFI bit */ + rlwinm r3, r4, 0, 21, 19 /* clear the ICFI bit */ + + /* + * The setting of the instruction cache enable (ICE) bit must be + * preceded by an isync instruction to prevent the cache from being + * enabled or disabled while an instruction access is in progress. + */ + isync + mtspr HID0, r4 /* Enable Instr Cache & Inval cache */ + mtspr HID0, r3 /* using 2 consec instructions */ + isync + blr + + .globl icache_disable +icache_disable: + mfspr r3, HID0 + rlwinm r3, r3, 0, 17, 15 /* clear the ICE bit */ + mtspr HID0, r3 + isync + blr + + .globl icache_status +icache_status: + mfspr r3, HID0 + rlwinm r3, r3, HID0_ICE_BITPOS + 1, 31, 31 + blr + + .globl dcache_enable +dcache_enable: + lis r4, 0 + ori r4, r4, HID0_DCE|HID0_DCFI /* set DCE & DCFI bit */ + rlwinm r3, r4, 0, 22, 20 /* clear the DCFI bit */ + + /* Enable address translation in MSR bit */ + mfmsr r5 + ori r5, r5, 0x + + + /* + * The setting of the instruction cache enable (ICE) bit must be + * preceded by an isync instruction to prevent the cache from being + * enabled or disabled while an instruction access is in progress. + */ + isync + mtspr HID0, r4 /* Enable Data Cache & Inval cache*/ + mtspr HID0, r3 /* using 2 consec instructions */ + isync + blr + + .globl dcache_disable +dcache_disable: + mfspr r3, HID0 + rlwinm r3, r3, 0, 18, 16 /* clear the DCE bit */ + mtspr HID0, r3 + isync + blr + + .globl dcache_status +dcache_status: + mfspr r3, HID0 + rlwinm r3, r3, HID0_DCE_BITPOS + 1, 31, 31 + blr + + .globl get_pvr +get_pvr: + mfspr r3, PVR + blr + +/*------------------------------------------------------------------------------*/ + +/* + * void relocate_code (addr_sp, gd, addr_moni) + * + * This "function" does not return, instead it continues in RAM + * after relocating the monitor code. + * + * r3 = dest + * r4 = src + * r5 = length in bytes + * r6 = cachelinesize + */ + .globl relocate_code +relocate_code: + mr r1, r3 /* Set new stack pointer */ + mr r9, r4 /* Save copy of Global Data pointer */ + mr r10, r5 /* Save copy of Destination Address */ + + GET_GOT + mr r3, r5 /* Destination Address */ + lis r4, CONFIG_SYS_MONITOR_BASE@h /* Source Address */ + ori r4, r4, CONFIG_SYS_MONITOR_BASE@l + lwz r5, GOT(__init_end) + sub r5, r5, r4 + li r6, CONFIG_SYS_CACHELINE_SIZE /* Cache Line Size */ + + /* + * Fix GOT pointer: + * + * New GOT-PTR = (old GOT-PTR - CONFIG_SYS_MONITOR_BASE) + Destination Address + * + * Offset: + */ + sub r15, r10, r4 + + /* First our own GOT */ + add r12, r12, r15 + /* then the one used by the C code */ + add r30, r30, r15 + + /* + * Now relocate code + */ + + cmplw cr1,r3,r4 + addi r0,r5,3 + srwi. r0,r0,2 + beq cr1,4f /* In place copy is not necessary */ + beq 7f /* Protect against 0 count */ + mtctr r0 + bge cr1,2f + + la r8,-4(r4) + la r7,-4(r3) +1: lwzu r0,4(r8) + stwu r0,4(r7) + bdnz 1b + b 4f + +2: slwi r0,r0,2 + add r8,r4,r0 + add r7,r3,r0 +3: lwzu r0,-4(r8) + stwu r0,-4(r7) + bdnz 3b + +/* + * Now flush the cache: note that we must start from a cache aligned + * address. Otherwise we might miss one cache line. + */ +4: cmpwi r6,0 + add r5,r3,r5 + beq 7f /* Always flush prefetch queue in any case */ + subi r0,r6,1 + andc r3,r3,r0 + mfspr r7,HID0 /* don't do dcbst if dcache is disabled */ + rlwinm r7,r7,HID0_DCE_BITPOS+1,31,31 + cmpwi r7,0 + beq 9f + mr r4,r3 +5: dcbst 0,r4 + add r4,r4,r6 + cmplw r4,r5 + blt 5b + sync /* Wait for all dcbst to complete on bus */ +9: mfspr r7,HID0 /* don't do icbi if icache is disabled */ + rlwinm r7,r7,HID0_ICE_BITPOS+1,31,31 + cmpwi r7,0 + beq 7f + mr r4,r3 +6: icbi 0,r4 + add r4,r4,r6 + cmplw r4,r5 + blt 6b +7: sync /* Wait for all icbi to complete on bus */ + isync + +/* + * We are done. Do not return, instead branch to second part of board + * initialization, now running from RAM. + */ + + addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET + mtlr r0 + blr + +in_ram: + + /* + * Relocation Function, r12 point to got2+0x8000 + * + * Adjust got2 pointers, no need to check for 0, this code + * already puts a few entries in the table. + */ + li r0,__got2_entries@sectoff@l + la r3,GOT(_GOT2_TABLE_) + lwz r11,GOT(_GOT2_TABLE_) + mtctr r0 + sub r11,r3,r11 + addi r3,r3,-4 +1: lwzu r0,4(r3) + cmpwi r0,0 + beq- 2f + add r0,r0,r11 + stw r0,0(r3) +2: bdnz 1b + + /* + * Now adjust the fixups and the pointers to the fixups + * in case we need to move ourselves again. + */ + li r0,__fixup_entries@sectoff@l + lwz r3,GOT(_FIXUP_TABLE_) + cmpwi r0,0 + mtctr r0 + addi r3,r3,-4 + beq 4f +3: lwzu r4,4(r3) + lwzux r0,r4,r11 + add r0,r0,r11 + stw r10,0(r3) + stw r0,0(r4) + bdnz 3b +4: +clear_bss: + /* + * Now clear BSS segment + */ + lwz r3,GOT(__bss_start) + lwz r4,GOT(_end) + + cmplw 0, r3, r4 + beq 6f + + li r0, 0 +5: + stw r0, 0(r3) + addi r3, r3, 4 + cmplw 0, r3, r4 + bne 5b +6: + + mr r3, r9 /* Global Data pointer */ + mr r4, r10 /* Destination Address */ + bl board_init_r + + /* + * Copy exception vector code to low memory + * + * r3: dest_addr + * r7: source address, r8: end address, r9: target address + */ + .globl trap_init +trap_init: + mflr r4 /* save link register */ + GET_GOT + lwz r7, GOT(_start) + lwz r8, GOT(_end_of_vectors) + + li r9, 0x100 /* reset vector always at 0x100 */ + + cmplw 0, r7, r8 + bgelr /* return if r7>=r8 - just in case */ +1: + lwz r0, 0(r7) + stw r0, 0(r9) + addi r7, r7, 4 + addi r9, r9, 4 + cmplw 0, r7, r8 + bne 1b + + /* + * relocate `hdlr' and `int_return' entries + */ + li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET + li r8, Alignment - _start + EXC_OFF_SYS_RESET +2: + bl trap_reloc + addi r7, r7, 0x100 /* next exception vector */ + cmplw 0, r7, r8 + blt 2b + + li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET + bl trap_reloc + + li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET + bl trap_reloc + + li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET + li r8, SystemCall - _start + EXC_OFF_SYS_RESET +3: + bl trap_reloc + addi r7, r7, 0x100 /* next exception vector */ + cmplw 0, r7, r8 + blt 3b + + li r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET + li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET +4: + bl trap_reloc + addi r7, r7, 0x100 /* next exception vector */ + cmplw 0, r7, r8 + blt 4b + + mfmsr r3 /* now that the vectors have */ + lis r7, MSR_IP@h /* relocated into low memory */ + ori r7, r7, MSR_IP@l /* MSR[IP] can be turned off */ + andc r3, r3, r7 /* (if it was on) */ + SYNC /* Some chip revs need this... */ + mtmsr r3 + SYNC + + mtlr r4 /* restore link register */ + blr |