| /* SPDX-License-Identifier: GPL-2.0+ */ |
| /* |
| * 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> |
| */ |
| |
| /* U-Boot - Startup Code for PowerPC based Embedded Boards |
| * |
| * |
| * The processor starts at 0x00000100 and the code is executed |
| * from flash. The code is organized to be at an other address |
| * in memory, but as long we don't jump around before relocating, |
| * board_init lies at a quite high address and when the cpu has |
| * jumped there, everything is ok. |
| * This works because the cpu gives the FLASH (CS0) the whole |
| * address space at startup, and board_init lies as a echo of |
| * the flash somewhere up there in the memory map. |
| * |
| * board_init will change CS0 to be positioned at the correct |
| * address and (s)dram will be positioned at address 0 |
| */ |
| #include <asm-offsets.h> |
| #include <config.h> |
| #include <mpc8xx.h> |
| |
| #include <ppc_asm.tmpl> |
| #include <ppc_defs.h> |
| |
| #include <asm/cache.h> |
| #include <asm/mmu.h> |
| #include <asm/u-boot.h> |
| |
| /* We don't want the MMU yet. |
| */ |
| #undef MSR_KERNEL |
| #define MSR_KERNEL ( MSR_ME | MSR_RI ) /* Machine Check and Recoverable Interr. */ |
| |
| /* |
| * 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(__bss_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 */ |
| |
| . = EXC_OFF_SYS_RESET |
| .globl _start |
| _start: |
| lis r3, CONFIG_SYS_IMMR@h /* position IMMR */ |
| mtspr 638, r3 |
| |
| /* Initialize machine status; enable machine check interrupt */ |
| /*----------------------------------------------------------------------*/ |
| li r3, MSR_KERNEL /* Set ME, RI flags */ |
| mtmsr r3 |
| mtspr SRR1, r3 /* Make SRR1 match MSR */ |
| |
| mfspr r3, ICR /* clear Interrupt Cause Register */ |
| |
| /* 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 |
| |
| /* Reset the caches */ |
| /*----------------------------------------------------------------------*/ |
| |
| mfspr r3, IC_CST /* Clear error bits */ |
| mfspr r3, DC_CST |
| |
| lis r3, IDC_UNALL@h /* Unlock all */ |
| mtspr IC_CST, r3 |
| mtspr DC_CST, r3 |
| |
| lis r3, IDC_INVALL@h /* Invalidate all */ |
| mtspr IC_CST, r3 |
| mtspr DC_CST, r3 |
| |
| lis r3, IDC_DISABLE@h /* Disable data cache */ |
| mtspr DC_CST, r3 |
| |
| lis r3, IDC_ENABLE@h /* Enable instruction cache */ |
| mtspr IC_CST, r3 |
| |
| /* invalidate all tlb's */ |
| /*----------------------------------------------------------------------*/ |
| |
| tlbia |
| isync |
| |
| /* |
| * Calculate absolute address in FLASH and jump there |
| *----------------------------------------------------------------------*/ |
| |
| lis r3, CONFIG_SYS_MONITOR_BASE@h |
| ori r3, r3, CONFIG_SYS_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 */ |
| /*----------------------------------------------------------------------*/ |
| |
| /* |
| * Disable serialized ifetch and show cycles |
| * (i.e. set processor to normal mode). |
| * This is also a silicon bug workaround, see errata |
| */ |
| |
| li r2, 0x0007 |
| mtspr ICTRL, r2 |
| |
| /* Set up debug mode entry */ |
| |
| lis r2, CONFIG_SYS_DER@h |
| ori r2, r2, CONFIG_SYS_DER@l |
| mtspr DER, r2 |
| |
| /* set up the stack on top of internal DPRAM */ |
| lis r3, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@h |
| ori r3, r3, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@l |
| stw r0, -4(r3) |
| stw r0, -8(r3) |
| addi r1, r3, -8 |
| |
| bl board_init_f_alloc_reserve |
| addi r1, r3, -8 |
| |
| /* Zeroise the CPM dpram */ |
| lis r4, CONFIG_SYS_IMMR@h |
| ori r4, r4, (0x2000 - 4) |
| li r0, (0x2000 / 4) |
| mtctr r0 |
| li r0, 0 |
| 1: stwu r0, 4(r4) |
| bdnz 1b |
| |
| bl board_init_f_init_reserve |
| |
| /* let the C-code set up the rest */ |
| /* */ |
| /* Be careful to keep code relocatable ! */ |
| /*----------------------------------------------------------------------*/ |
| |
| GET_GOT /* initialize GOT access */ |
| |
| lis r3, CONFIG_SYS_IMMR@h |
| bl cpu_init_f /* run low-level CPU init code (from Flash) */ |
| |
| bl board_init_f /* run 1st part of board init code (from Flash) */ |
| |
| /* NOTREACHED - board_init_f() does not return */ |
| |
| |
| .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(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) |
| |
| /* No FPU on MPC8xx. This exception is not supposed to happen. |
| */ |
| 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) |
| |
| /* 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 |
| |
| /*------------------------------------------------------------------------------*/ |
| |
| /* |
| * 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 |
| 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 */ |
| 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 |
| cmpwi r0,0 |
| add r0,r0,r11 |
| stw r4,0(r3) |
| beq- 5f |
| stw r0,0(r4) |
| 5: bdnz 3b |
| 4: |
| clear_bss: |
| /* |
| * Now clear BSS segment |
| */ |
| lwz r3,GOT(__bss_start) |
| lwz r4,GOT(__bss_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 |
| |
| mtlr r4 /* restore link register */ |
| blr |