diff options
Diffstat (limited to 'arch/powerpc/cpu/mpc512x/start.S')
| -rw-r--r-- | arch/powerpc/cpu/mpc512x/start.S | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc512x/start.S b/arch/powerpc/cpu/mpc512x/start.S new file mode 100644 index 0000000..d26b617 --- /dev/null +++ b/arch/powerpc/cpu/mpc512x/start.S @@ -0,0 +1,711 @@ +/* + * Copyright (C) 1998 Dan Malek <dmalek@jlc.net> + * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> + * Copyright (C) 2000-2009 Wolfgang Denk <wd@denx.de> + * Copyright Freescale Semiconductor, Inc. 2004, 2006. + * + * 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 + * + * Based on the MPC83xx code. + */ + +/* + * U-Boot - Startup Code for MPC512x based Embedded Boards + */ + +#include <config.h> +#include <timestamp.h> +#include <version.h> + +#define CONFIG_521X 1 /* needed for Linux kernel header files*/ + +#include <asm/immap_512x.h> +#include "asm-offsets.h" + +#include <ppc_asm.tmpl> +#include <ppc_defs.h> + +#include <asm/cache.h> +#include <asm/mmu.h> + +#ifndef CONFIG_IDENT_STRING +#define CONFIG_IDENT_STRING "MPC512X" +#endif + +/* + * Floating Point enable, Machine Check and Recoverable Interr. + */ +#undef MSR_KERNEL +#ifdef DEBUG +#define MSR_KERNEL (MSR_FP|MSR_RI) +#else +#define MSR_KERNEL (MSR_FP|MSR_ME|MSR_RI) +#endif + +/* Macros for manipulating CSx_START/STOP */ +#define START_REG(start) ((start) >> 16) +#define STOP_REG(start, size) (((start) + (size) - 1) >> 16) + +/* + * 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 + +/* + * Magic number and version string + */ + .long 0x27051956 /* U-Boot Magic Number */ + .globl version_string +version_string: + .ascii U_BOOT_VERSION + .ascii " (", U_BOOT_DATE, " - ", U_BOOT_TIME, ")" + .ascii " ", CONFIG_IDENT_STRING, "\0" + +/* + * Vector Table + */ + .text + . = EXC_OFF_SYS_RESET + + .globl _start + /* Start from here after reset/power on */ +_start: + li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH */ + b boot_cold + + .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, UnknownException) + +/* 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) + +/* Floating Point Unit unavailable exception */ + STD_EXCEPTION(0x800, FPUnavailable, UnknownException) + +/* Decrementer */ + STD_EXCEPTION(0x900, Decrementer, timer_interrupt) + +/* Critical interrupt */ + STD_EXCEPTION(0xa00, Critical, UnknownException) + +/* System Call */ + STD_EXCEPTION(0xc00, SystemCall, UnknownException) + +/* Trace interrupt */ + STD_EXCEPTION(0xd00, Trace, UnknownException) + +/* Performance Monitor interrupt */ + STD_EXCEPTION(0xf00, PerfMon, UnknownException) + +/* Intruction Translation Miss */ + STD_EXCEPTION(0x1000, InstructionTLBMiss, UnknownException) + +/* Data Load Translation Miss */ + STD_EXCEPTION(0x1100, DataLoadTLBMiss, UnknownException) + +/* Data Store Translation Miss */ + STD_EXCEPTION(0x1200, DataStoreTLBMiss, UnknownException) + +/* Instruction Address Breakpoint */ + STD_EXCEPTION(0x1300, InstructionAddrBreakpoint, DebugException) + +/* System Management interrupt */ + STD_EXCEPTION(0x1400, SystemMgmtInterrupt, UnknownException) + + .globl _end_of_vectors +_end_of_vectors: + + . = 0x3000 +boot_cold: + /* Save msr contents */ + mfmsr r5 + + /* Set IMMR area to our preferred location */ + lis r4, CONFIG_DEFAULT_IMMR@h + lis r3, CONFIG_SYS_IMMR@h + ori r3, r3, CONFIG_SYS_IMMR@l + stw r3, IMMRBAR(r4) + mtspr MBAR, r3 /* IMMRBAR is mirrored into the MBAR SPR (311) */ + + /* Initialise the machine */ + bl cpu_early_init + + /* + * Set up Local Access Windows: + * + * 1) Boot/CS0 (boot FLASH) + * 2) On-chip SRAM (initial stack purposes) + */ + + /* Boot CS/CS0 window range */ + lis r3, CONFIG_SYS_IMMR@h + ori r3, r3, CONFIG_SYS_IMMR@l + + lis r4, START_REG(CONFIG_SYS_FLASH_BASE) + ori r4, r4, STOP_REG(CONFIG_SYS_FLASH_BASE, CONFIG_SYS_FLASH_SIZE) + stw r4, LPCS0AW(r3) + + /* + * The SRAM window has a fixed size (256K), so only the start address + * is necessary + */ + lis r4, START_REG(CONFIG_SYS_SRAM_BASE) & 0xff00 + stw r4, SRAMBAR(r3) + + /* + * According to MPC5121e RM, configuring local access windows should + * be followed by a dummy read of the config register that was + * modified last and an isync + */ + lwz r4, SRAMBAR(r3) + isync + + /* + * Set configuration of the Boot/CS0, the SRAM window does not have a + * config register so no params can be set for it + */ + lis r3, (CONFIG_SYS_IMMR + LPC_OFFSET)@h + ori r3, r3, (CONFIG_SYS_IMMR + LPC_OFFSET)@l + + lis r4, CONFIG_SYS_CS0_CFG@h + ori r4, r4, CONFIG_SYS_CS0_CFG@l + stw r4, CS0_CONFIG(r3) + + /* Master enable all CS's */ + lis r4, CS_CTRL_ME@h + ori r4, r4, CS_CTRL_ME@l + stw r4, CS_CTRL(r3) + + lis r4, (CONFIG_SYS_MONITOR_BASE)@h + ori r4, r4, (CONFIG_SYS_MONITOR_BASE)@l + addi r5, r4, in_flash - _start + EXC_OFF_SYS_RESET + mtlr r5 + blr + +in_flash: + lis r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@h + ori r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@l + + 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 & stack humble */ + /*------------------------------------------------------*/ + + GET_GOT /* initialize GOT access */ + + /* r3: IMMR */ + lis r3, CONFIG_SYS_IMMR@h + /* run low-level CPU init code (in Flash) */ + bl cpu_init_f + + /* r3: BOOTFLAG */ + mr r3, r21 + /* run 1st part of board init code (in Flash) */ + bl board_init_f + + /* NOTREACHED - board_init_f() does not return */ + +/* + * 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 machine, it expects original MSR contents to be in r5. + */ +cpu_early_init: + /* 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 */ +#ifdef DEBUG + rlwimi r3, r5, 0, 21, 22 /* debugger might set SE, BE bits */ +#endif + mtmsr r3 + SYNC + mtspr SRR1, r3 /* Mirror current MSR state in SRR1 */ + + lis r3, CONFIG_SYS_IMMR@h + +#if defined(CONFIG_WATCHDOG) + /* Initialise the watchdog and reset it */ + /*--------------------------------------*/ + lis r4, CONFIG_SYS_WATCHDOG_VALUE + ori r4, r4, (SWCRR_SWEN | SWCRR_SWRI | SWCRR_SWPR) + stw r4, SWCRR(r3) + + /* reset */ + li r4, 0x556C + sth r4, SWSRR@l(r3) + li r4, 0x0 + ori r4, r4, 0xAA39 + sth r4, SWSRR@l(r3) +#else + /* Disable the watchdog */ + /*----------------------*/ + lwz r4, SWCRR(r3) + /* + * Check to see if it's enabled for disabling: once disabled by s/w + * it's not possible to re-enable it + */ + andi. r4, r4, 0x4 + beq 1f + xor r4, r4, r4 + stw r4, SWCRR(r3) +1: +#endif /* CONFIG_WATCHDOG */ + + /* 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 + + lis r3, CONFIG_SYS_HID2@h + ori r3, r3, CONFIG_SYS_HID2@l + SYNC + mtspr HID2, r3 + sync + blr + + +/* Cache functions. + * + * Note: requires that all cache bits in + * HID0 are in the low half word. + */ + .globl icache_enable +icache_enable: + mfspr r3, HID0 + ori r3, r3, HID0_ICE + lis r4, 0 + ori r4, r4, HID0_ILOCK + andc r3, r3, r4 + ori r4, r3, HID0_ICFI + isync + mtspr HID0, r4 /* sets enable and invalidate, clears lock */ + isync + mtspr HID0, r3 /* clears invalidate */ + blr + + .globl icache_disable +icache_disable: + mfspr r3, HID0 + lis r4, 0 + ori r4, r4, HID0_ICE|HID0_ILOCK + andc r3, r3, r4 + ori r4, r3, HID0_ICFI + isync + mtspr HID0, r4 /* sets invalidate, clears enable and lock*/ + isync + mtspr HID0, r3 /* clears invalidate */ + blr + + .globl icache_status +icache_status: + mfspr r3, HID0 + rlwinm r3, r3, (31 - HID0_ICE_SHIFT + 1), 31, 31 + blr + + .globl dcache_enable +dcache_enable: + mfspr r3, HID0 + li r5, HID0_DCFI|HID0_DLOCK + andc r3, r3, r5 + mtspr HID0, r3 /* no invalidate, unlock */ + ori r3, r3, HID0_DCE + ori r5, r3, HID0_DCFI + mtspr HID0, r5 /* enable + invalidate */ + mtspr HID0, r3 /* enable */ + sync + blr + + .globl dcache_disable +dcache_disable: + mfspr r3, HID0 + lis r4, 0 + ori r4, r4, HID0_DCE|HID0_DLOCK + andc r3, r3, r4 + ori r4, r3, HID0_DCI + sync + mtspr HID0, r4 /* sets invalidate, clears enable and lock */ + sync + mtspr HID0, r3 /* clears invalidate */ + blr + + .globl dcache_status +dcache_status: + mfspr r3, HID0 + rlwinm r3, r3, (31 - HID0_DCE_SHIFT + 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) + + /* copy */ +1: lwzu r0,4(r8) + stwu r0,4(r7) + bdnz 1b + + addi r0,r5,3 + srwi. r0,r0,2 + mtctr r0 + la r8,-4(r4) + la r7,-4(r3) + + /* and compare */ +20: lwzu r20,4(r8) + lwzu r21,4(r7) + xor. r22, r20, r21 + bne 30f + bdnz 20b + b 4f + + /* compare failed */ +30: li r3, 0 + blr + +2: slwi r0,r0,2 /* re copy in reverse order ... y do we needed it? */ + 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 + 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 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_Trace - _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 |