| /* |
| * 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 <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 r14 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 " (", __DATE__, " - ", __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(CFG_DEFAULT_MBAR) && !defined(CFG_RAMBOOT) |
| lis r3, CFG_MBAR@h |
| ori r3, r3, CFG_MBAR@l |
| |
| /* MBAR is mirrored into the MBAR SPR */ |
| mtspr MBAR,r3 |
| mtspr SPRN_SPRG7W,r3 |
| lis r4, CFG_DEFAULT_MBAR@h |
| stw r3, 0(r4) |
| #endif /* CFG_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, CFG_INIT_RAM_ADDR@h |
| ori r3, r3, CFG_INIT_RAM_ADDR@l |
| ori r1, r3, CFG_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 |
| mfspr r4,DAR |
| stw r4,_DAR(r21) |
| mfspr r5,DSISR |
| stw r5,_DSISR(r21) |
| addi r3,r1,STACK_FRAME_OVERHEAD |
| li r20,MSR_KERNEL |
| rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */ |
| rlwimi r20,r23,0,25,25 /* copy IP bit from saved MSR */ |
| lwz r6,GOT(transfer_to_handler) |
| mtlr r6 |
| blrl |
| .L_Alignment: |
| .long AlignmentException - _start + EXC_OFF_SYS_RESET |
| .long int_return - _start + EXC_OFF_SYS_RESET |
| |
| /* Program check exception */ |
| . = 0x700 |
| ProgramCheck: |
| EXCEPTION_PROLOG |
| addi r3,r1,STACK_FRAME_OVERHEAD |
| li r20,MSR_KERNEL |
| rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */ |
| rlwimi r20,r23,0,25,25 /* copy IP bit from saved MSR */ |
| lwz r6,GOT(transfer_to_handler) |
| mtlr r6 |
| blrl |
| .L_ProgramCheck: |
| .long ProgramCheckException - _start + EXC_OFF_SYS_RESET |
| .long int_return - _start + EXC_OFF_SYS_RESET |
| |
| 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, CFG_HID0_INIT@h |
| ori r3, r3, CFG_HID0_INIT@l |
| SYNC |
| mtspr HID0, r3 |
| |
| lis r3, CFG_HID0_FINAL@h |
| ori r3, r3, CFG_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/ppc/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, CFG_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 */ |
| |
| mr r3, r5 /* Destination Address */ |
| lis r4, CFG_MONITOR_BASE@h /* Source Address */ |
| ori r4, r4, CFG_MONITOR_BASE@l |
| lwz r5, GOT(__init_end) |
| sub r5, r5, r4 |
| li r6, CFG_CACHELINE_SIZE /* Cache Line Size */ |
| |
| /* |
| * Fix GOT pointer: |
| * |
| * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address |
| * |
| * Offset: |
| */ |
| sub r15, r10, r4 |
| |
| /* First our own GOT */ |
| add r14, r14, 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, r14 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) |
| add r0,r0,r11 |
| stw r0,0(r3) |
| bdnz 1b |
| |
| /* |
| * Now adjust the fixups and the pointers to the fixups |
| * in case we need to move ourselves again. |
| */ |
| 2: 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: |
| 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 */ |
| |
| mflr r4 /* save link register */ |
| 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 |
| |
| /* |
| * Function: relocate entries for one exception vector |
| */ |
| trap_reloc: |
| lwz r0, 0(r7) /* hdlr ... */ |
| add r0, r0, r3 /* ... += dest_addr */ |
| stw r0, 0(r7) |
| |
| lwz r0, 4(r7) /* int_return ... */ |
| add r0, r0, r3 /* ... += dest_addr */ |
| stw r0, 4(r7) |
| |
| blr |
