| /* |
| * Copyright (C) 1998 Dan Malek <dmalek@jlc.net> |
| * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> |
| * Copyright (C) 2000, 2001, 2002 Wolfgang Denk <wd@denx.de> |
| * Copyright (C) 2003 Martin Winistoerfer, martinwinistoerfer@gmx.ch. |
| * |
| * 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 |
| */ |
| |
| /* |
| * File: start.S |
| * |
| * Discription: startup code |
| * |
| */ |
| |
| #include <config.h> |
| #include <mpc5xx.h> |
| #include <version.h> |
| |
| #define CONFIG_5xx 1 /* needed for Linux kernel header files */ |
| #define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */ |
| |
| #include <ppc_asm.tmpl> |
| #include <ppc_defs.h> |
| |
| #include <linux/config.h> |
| #include <asm/processor.h> |
| |
| #ifndef CONFIG_IDENT_STRING |
| #define CONFIG_IDENT_STRING "" |
| #endif |
| |
| /* We don't have a MMU. |
| */ |
| #undef MSR_KERNEL |
| #define MSR_KERNEL ( MSR_ME | MSR_RI ) /* Machine Check and Recoverable Interr. */ |
| |
| /* |
| * 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 |
| |
| /* |
| * r3 - 1st arg to board_init(): IMMP pointer |
| * r4 - 2nd arg to board_init(): boot flag |
| */ |
| .text |
| .long 0x27051956 /* U-Boot Magic Number */ |
| .globl version_string |
| version_string: |
| .ascii U_BOOT_VERSION |
| .ascii " (", __DATE__, " - ", __TIME__, ")" |
| .ascii CONFIG_IDENT_STRING, "\0" |
| |
| . = EXC_OFF_SYS_RESET |
| .globl _start |
| _start: |
| mfspr r3, 638 |
| li r4, CFG_ISB /* Set ISB bit */ |
| or r3, r3, r4 |
| mtspr 638, r3 |
| li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH */ |
| b boot_cold |
| |
| . = EXC_OFF_SYS_RESET + 0x20 |
| |
| .globl _start_warm |
| _start_warm: |
| li r21, BOOTFLAG_WARM /* Software reboot */ |
| b boot_warm |
| |
| boot_cold: |
| boot_warm: |
| |
| /* Initialize machine status; enable machine check interrupt */ |
| /*----------------------------------------------------------------------*/ |
| li r3, MSR_KERNEL /* Set ME, RI flags */ |
| mtmsr r3 |
| mtspr SRR1, r3 /* Make SRR1 match MSR */ |
| |
| /* Initialize debug port registers */ |
| /*----------------------------------------------------------------------*/ |
| xor r0, r0, r0 /* Clear R0 */ |
| mtspr LCTRL1, r0 /* Initialize debug port regs */ |
| mtspr LCTRL2, r0 |
| mtspr COUNTA, r0 |
| mtspr COUNTB, r0 |
| |
| /* |
| * Calculate absolute address in FLASH and jump there |
| *----------------------------------------------------------------------*/ |
| |
| lis r3, CFG_MONITOR_BASE@h |
| ori r3, r3, CFG_MONITOR_BASE@l |
| addi r3, r3, in_flash - _start + EXC_OFF_SYS_RESET |
| mtlr r3 |
| blr |
| |
| in_flash: |
| |
| /* Initialize some SPRs that are hard to access from C */ |
| /*----------------------------------------------------------------------*/ |
| |
| lis r3, CFG_IMMR@h /* Pass IMMR as arg1 to C routine */ |
| lis r2, CFG_INIT_SP_ADDR@h |
| ori r1, r2, CFG_INIT_SP_ADDR@l /* Set up the stack in internal SRAM */ |
| /* Note: R0 is still 0 here */ |
| stwu r0, -4(r1) /* Clear final stack frame so that */ |
| stwu r0, -4(r1) /* stack backtraces terminate cleanly */ |
| |
| /* |
| * Disable serialized ifetch and show cycles |
| * (i.e. set processor to normal mode) for maximum |
| * performance. |
| */ |
| |
| li r2, 0x0007 |
| mtspr ICTRL, r2 |
| |
| /* Set up debug mode entry */ |
| |
| lis r2, CFG_DER@h |
| ori r2, r2, CFG_DER@l |
| mtspr DER, r2 |
| |
| /* 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 (from Flash) */ |
| |
| mr r3, r21 |
| /* r3: BOOTFLAG */ |
| bl board_init_f /* run 1st part of board init code (from Flash) */ |
| |
| |
| .globl _start_of_vectors |
| _start_of_vectors: |
| |
| /* Machine check */ |
| STD_EXCEPTION(0x200, MachineCheck, MachineCheckException) |
| |
| /* Data Storage exception. "Never" generated on the 860. */ |
| STD_EXCEPTION(0x300, DataStorage, UnknownException) |
| |
| /* Instruction Storage exception. "Never" generated on the 860. */ |
| 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 */ |
| 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 */ |
| 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 |
| |
| /* FPU on MPC5xx available. We will use it later. |
| */ |
| 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) |
| |
| . = 0xc00 |
| /* |
| * r0 - SYSCALL number |
| * r3-... arguments |
| */ |
| SystemCall: |
| addis r11,r0,0 /* get functions table addr */ |
| ori r11,r11,0 /* Note: this code is patched in trap_init */ |
| addis r12,r0,0 /* get number of functions */ |
| ori r12,r12,0 |
| |
| cmplw 0, r0, r12 |
| bge 1f |
| |
| rlwinm r0,r0,2,0,31 /* fn_addr = fn_tbl[r0] */ |
| add r11,r11,r0 |
| lwz r11,0(r11) |
| |
| li r20,0xd00-4 /* Get stack pointer */ |
| lwz r12,0(r20) |
| subi r12,r12,12 /* Adjust stack pointer */ |
| li r0,0xc00+_end_back-SystemCall |
| cmplw 0, r0, r12 /* Check stack overflow */ |
| bgt 1f |
| stw r12,0(r20) |
| |
| mflr r0 |
| stw r0,0(r12) |
| mfspr r0,SRR0 |
| stw r0,4(r12) |
| mfspr r0,SRR1 |
| stw r0,8(r12) |
| |
| li r12,0xc00+_back-SystemCall |
| mtlr r12 |
| mtspr SRR0,r11 |
| |
| 1: SYNC |
| rfi |
| |
| _back: |
| |
| mfmsr r11 /* Disable interrupts */ |
| li r12,0 |
| ori r12,r12,MSR_EE |
| andc r11,r11,r12 |
| SYNC /* Some chip revs need this... */ |
| mtmsr r11 |
| SYNC |
| |
| li r12,0xd00-4 /* restore regs */ |
| lwz r12,0(r12) |
| |
| lwz r11,0(r12) |
| mtlr r11 |
| lwz r11,4(r12) |
| mtspr SRR0,r11 |
| lwz r11,8(r12) |
| mtspr SRR1,r11 |
| |
| addi r12,r12,12 /* Adjust stack pointer */ |
| li r20,0xd00-4 |
| stw r12,0(r20) |
| |
| SYNC |
| rfi |
| _end_back: |
| |
| STD_EXCEPTION(0xd00, SingleStep, UnknownException) |
| |
| STD_EXCEPTION(0xe00, Trap_0e, UnknownException) |
| STD_EXCEPTION(0xf00, Trap_0f, UnknownException) |
| |
| /* On the MPC8xx, this is a software emulation interrupt. It occurs |
| * for all unimplemented and illegal instructions. |
| */ |
| STD_EXCEPTION(0x1000, SoftEmu, SoftEmuException) |
| STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException) |
| STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException) |
| STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException) |
| STD_EXCEPTION(0x1400, DataTLBError, UnknownException) |
| |
| STD_EXCEPTION(0x1500, Reserved5, UnknownException) |
| STD_EXCEPTION(0x1600, Reserved6, UnknownException) |
| STD_EXCEPTION(0x1700, Reserved7, UnknownException) |
| STD_EXCEPTION(0x1800, Reserved8, UnknownException) |
| STD_EXCEPTION(0x1900, Reserved9, UnknownException) |
| STD_EXCEPTION(0x1a00, ReservedA, UnknownException) |
| STD_EXCEPTION(0x1b00, ReservedB, UnknownException) |
| |
| STD_EXCEPTION(0x1c00, DataBreakpoint, UnknownException) |
| STD_EXCEPTION(0x1d00, InstructionBreakpoint, DebugException) |
| STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException) |
| STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException) |
| |
| |
| .globl _end_of_vectors |
| _end_of_vectors: |
| |
| |
| . = 0x2000 |
| |
| /* |
| * 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) |
| mtspr SPRG2,r22 /* r1 is now kernel sp */ |
| 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 |
| |
| |
| /* |
| * unsigned int get_immr (unsigned int mask) |
| * |
| * return (mask ? (IMMR & mask) : IMMR); |
| */ |
| .globl get_immr |
| get_immr: |
| mr r4,r3 /* save mask */ |
| mfspr r3, IMMR /* IMMR */ |
| cmpwi 0,r4,0 /* mask != 0 ? */ |
| beq 4f |
| and r3,r3,r4 /* IMMR & mask */ |
| 4: |
| 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 in SRAM */ |
| mr r9, r4 /* Save copy of global data pointer in SRAM */ |
| mr r10, r5 /* Save copy of monitor destination Address in SRAM */ |
| |
| 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 |
| |
| /* |
| * 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 |
| /* the 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 4f /* 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 |
| |
| 4: sync |
| 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 |
| |
| 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) |
| |
| sync |
| isync |
| |
| blr |