diff options
Diffstat (limited to 'src/cpu')
| -rw-r--r-- | src/cpu/ppc/ppc4xx/ppc4xx.inc | 703 |
1 files changed, 34 insertions, 669 deletions
diff --git a/src/cpu/ppc/ppc4xx/ppc4xx.inc b/src/cpu/ppc/ppc4xx/ppc4xx.inc index b365988d6c..a0b2bc8333 100644 --- a/src/cpu/ppc/ppc4xx/ppc4xx.inc +++ b/src/cpu/ppc/ppc4xx/ppc4xx.inc @@ -1,4 +1,3 @@ -#if 0 /* * Copyright (C) 1998 Dan Malek <dmalek@jlc.net> * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> @@ -48,24 +47,16 @@ * Base on the U-Boot Startup Code * * The processor starts at 0xfffffffc and the code is executed - * from flash/rom. - * 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 memorymap. + * from flash/rom. * - * board_init will change CS0 to be positioned at the correct - * address and (s)dram will be positioned at address 0 + * The purpose of this code is: + * - initalize the processor to a known state + * - turn on the I cache so things execute at a reasonable speed + * - set up a temporary stack in D cache */ -#include <ppc_asm.tmpl> -#include <ppc_defs.h> - .globl _start -_start: +#include "ppc4xx.h" -/*****************************************************************************/ addi r4,r0,0x0000 mtspr sgr,r4 mtspr dcwr,r4 @@ -76,675 +67,49 @@ _start: addi r4,r0,0x1000 /* set ME bit (Machine Exceptions) */ oris r4,r4,0x0002 /* set CE bit (Critical Exceptions) */ mtmsr r4 /* change MSR */ - addi r4,r0,(0xFFFF-0x10000) /* set r4 to 0xFFFFFFFF (status in the */ - /* dbsr is cleared by setting bits to 1) */ + addi r4,r0,(0xFFFF-0x10000) /* set r4 to 0xFFFFFFFF (status in */ + /* the dbsr is cleared by setting */ + /* bits to 1) */ mtdbsr r4 /* clear/reset the dbsr */ - /*----------------------------------------------------------------------- */ - /* Invalidate I and D caches. Enable I cache for defined memory regions */ - /* to speed things up. Leave the D cache disabled for now. It will be */ - /* enabled/left disabled later based on user selected menu options. */ - /* Be aware that the I cache may be disabled later based on the menu */ - /* options as well. See miscLib/main.c. */ - /*----------------------------------------------------------------------- */ - bl invalidate_icache - bl invalidate_dcache - - /*----------------------------------------------------------------------- */ - /* Enable two 128MB cachable regions. */ - /*----------------------------------------------------------------------- */ - addis r4,r0,0x8000 - addi r4,r4,0x0001 - mticcr r4 /* instruction cache */ - isync - - addis r4,r0,0x0000 - addi r4,r4,0x0000 - mtdccr r4 /* data cache */ - -#if !(defined(CFG_EBC_PB0AP) && defined(CFG_EBC_PB0CR)) - /*----------------------------------------------------------------------- */ - /* Tune the speed and size for flash CS0 */ - /*----------------------------------------------------------------------- */ - bl ext_bus_cntlr_init -#endif - -#if defined(CONFIG_405EP) - /*----------------------------------------------------------------------- */ - /* DMA Status, clear to come up clean */ - /*----------------------------------------------------------------------- */ - addis r3,r0, 0xFFFF /* Clear all existing DMA status */ - ori r3,r3, 0xFFFF - mtdcr dmasr, r3 - - bl ppc405ep_init /* do ppc405ep specific init */ -#endif /* CONFIG_405EP */ - - /*----------------------------------------------------------------------- */ - /* Setup temporary stack in DCACHE or OCM if needed for SDRAM SPD. */ - /*----------------------------------------------------------------------- */ -#ifdef CFG_INIT_DCACHE_CS - /*----------------------------------------------------------------------- */ - /* Memory Bank x (nothingness) initialization 1GB+64MEG */ - /* used as temporary stack pointer for stage0 */ - /*----------------------------------------------------------------------- */ - li r4,PBxAP - mtdcr ebccfga,r4 - lis r4,0x0380 - ori r4,r4,0x0480 - mtdcr ebccfgd,r4 - - addi r4,0,PBxCR - mtdcr ebccfga,r4 - lis r4,0x400D - ori r4,r4,0xa000 - mtdcr ebccfgd,r4 - - /* turn on data chache for this region */ - lis r4,0x0080 - mtdccr r4 - - /* set stack pointer and clear stack to known value */ - - lis r1,CFG_INIT_RAM_ADDR@h - ori r1,r1,CFG_INIT_SP_OFFSET@l - - li r4,2048 /* we store 2048 words to stack */ - mtctr r4 - - lis r2,CFG_INIT_RAM_ADDR@h /* we also clear data area */ - ori r2,r2,CFG_INIT_RAM_END@l /* so cant copy value from r1 */ - - lis r4,0xdead /* we store 0xdeaddead in the stack */ - ori r4,r4,0xdead - -..stackloop: - stwu r4,-4(r2) - bdnz ..stackloop - - 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 */ - /* - * Set up a dummy frame to store reset vector as return address. - * this causes stack underflow to reset board. - */ - stwu r1, -8(r1) /* Save back chain and move SP */ - addis r0, 0, RESET_VECTOR@h /* Address of reset vector */ - ori r0, r0, RESET_VECTOR@l - stwu r1, -8(r1) /* Save back chain and move SP */ - stw r0, +12(r1) /* Save return addr (underflow vect) */ -#endif /* CFG_INIT_DCACHE_CS */ - - /*----------------------------------------------------------------------- */ - /* Initialize SDRAM Controller */ - /*----------------------------------------------------------------------- */ - bl sdram_init - - /* - * Setup temporary stack pointer only for boards - * that do not use SDRAM SPD I2C stuff since it - * is already initialized to use DCACHE or OCM - * stacks. - */ -#if !(defined(CFG_INIT_DCACHE_CS) || defined(CFG_TEMP_STACK_OCM)) - lis r1, CFG_INIT_RAM_ADDR@h - ori r1,r1,CFG_INIT_SP_OFFSET /* set up the stack in SDRAM */ - - 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 */ /* - * Set up a dummy frame to store reset vector as return address. - * this causes stack underflow to reset board. + * Invalidate I and D caches. Enable I cache for defined memory + * regions to speed things up. Enable D cache for use as + * temporary memory until real memory is enabled. */ - stwu r1, -8(r1) /* Save back chain and move SP */ - lis r0, RESET_VECTOR@h /* Address of reset vector */ - ori r0, r0, RESET_VECTOR@l - stwu r1, -8(r1) /* Save back chain and move SP */ - stw r0, +12(r1) /* Save return addr (underflow vect) */ -#endif /* !(CFG_INIT_DCACHE_CS || !CFG_TEM_STACK_OCM) */ - - GET_GOT /* initialize GOT access */ - - bl cpu_init_f /* run low-level CPU init code (from Flash) */ - /* NEVER RETURNS! */ - bl board_init_f /* run first part of init code (from Flash) */ - - - -/* Cache functions. -*/ -invalidate_icache: - iccci r0,r0 /* for 405, iccci invalidates the */ - blr /* entire I cache */ - -invalidate_dcache: - addi r6,0,0x0000 /* clear GPR 6 */ - /* Do loop for # of dcache congruence classes. */ - addi r7,r0, (CFG_DCACHE_SIZE / CFG_CACHELINE_SIZE / 2) - /* NOTE: dccci invalidates both */ - mtctr r7 /* ways in the D cache */ -..dcloop: - dccci 0,r6 /* invalidate line */ - addi r6,r6, CFG_CACHELINE_SIZE /* bump to next line */ - bdnz ..dcloop - blr - -flush_dcache: - addis r9,r0,0x0002 /* set mask for EE and CE msr bits */ - ori r9,r9,0x8000 - mfmsr r12 /* save msr */ - andc r9,r12,r9 - mtmsr r9 /* disable EE and CE */ - addi r10,r0,0x0001 /* enable data cache for unused memory */ - mfdccr r9 /* region 0xF8000000-0xFFFFFFFF via */ - or r10,r10,r9 /* bit 31 in dccr */ - mtdccr r10 - - /* do loop for # of congruence classes. */ - addi r10,r0,(CFG_DCACHE_SIZE / CFG_CACHELINE_SIZE / 2) - addi r11,r0,(CFG_DCACHE_SIZE / 2) /* D cache set size - 2 way sets */ - mtctr r10 - addi r10,r0,(0xE000-0x10000) /* start at 0xFFFFE000 */ - add r11,r10,r11 /* add to get to other side of cache line */ -..flush_dcache_loop: - lwz r3,0(r10) /* least recently used side */ - lwz r3,0(r11) /* the other side */ - dccci r0,r11 /* invalidate both sides */ - addi r10,r10,CFG_CACHELINE_SIZE /* bump to next line */ - addi r11,r11,CFG_CACHELINE_SIZE /* bump to next line */ - bdnz ..flush_dcache_loop - sync /* allow memory access to complete */ - mtdccr r9 /* restore dccr */ - mtmsr r12 /* restore msr */ - blr - - .globl icache_enable -icache_enable: - mflr r8 bl invalidate_icache - mtlr r8 - isync - addis r3,r0, 0x8000 /* set bit 0 */ - mticcr r3 - blr - - .globl icache_disable -icache_disable: - addis r3,r0, 0x0000 /* clear bit 0 */ - mticcr r3 - isync - blr - - .globl icache_status -icache_status: - mficcr r3 - srwi r3, r3, 31 /* >>31 => select bit 0 */ - blr - - .globl dcache_enable -dcache_enable: - mflr r8 bl invalidate_dcache - mtlr r8 - isync - addis r3,r0, 0x8000 /* set bit 0 */ - mtdccr r3 - blr - - .globl dcache_disable -dcache_disable: - mflr r8 - bl flush_dcache - mtlr r8 - addis r3,r0, 0x0000 /* clear bit 0 */ - mtdccr r3 - blr - - .globl dcache_status -dcache_status: - mfdccr r3 - srwi r3, r3, 31 /* >>31 => select bit 0 */ - blr - - .globl get_pvr -get_pvr: - mfspr r3, PVR - blr -#if !defined(CONFIG_440) - .globl wr_pit -wr_pit: - mtspr pit, r3 - blr -#endif - - .globl wr_tcr -wr_tcr: - mtspr tcr, r3 - blr - -/*------------------------------------------------------------------------------- */ -/* Function: ppcDcbf */ -/* Description: Data Cache block flush */ -/* Input: r3 = effective address */ -/* Output: none. */ -/*------------------------------------------------------------------------------- */ - .globl ppcDcbf -ppcDcbf: - dcbf r0,r3 - blr - -/*------------------------------------------------------------------------------- */ -/* Function: ppcDcbi */ -/* Description: Data Cache block Invalidate */ -/* Input: r3 = effective address */ -/* Output: none. */ -/*------------------------------------------------------------------------------- */ - .globl ppcDcbi -ppcDcbi: - dcbi r0,r3 - blr - -/*------------------------------------------------------------------------------- */ -/* Function: ppcSync */ -/* Description: Processor Synchronize */ -/* Input: none. */ -/* Output: none. */ -/*------------------------------------------------------------------------------- */ - .globl ppcSync -ppcSync: - sync - 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 Init 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: + /* + * Enable two 128MB cachable instruction regions * - * 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 + * 0x00000000 - 0x07FFFFFF + * 0xF8000000 - 0xFFFFFFFF */ - 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 */ + lis r4,0x8000 + addi r4,r4,0x0001 + mticcr r4 /* instruction cache enable */ 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 /* NEVER RETURNS! */ - -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 /* Init 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 + * Enable dcache region containing DCACHE_RAM_BASE + * and set region to write-back */ -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 - - -#ifdef CONFIG_405EP -ppc405ep_init: - /* - !----------------------------------------------------------------------- - ! Check FPGA for PCI internal/external arbitration - ! If board is set to internal arbitration, update cpc0_pci - !----------------------------------------------------------------------- - */ - addi r3,0,CPC0_PCI_HOST_CFG_EN -#ifdef CONFIG_BUBINGA405EP - addis r5,r0,FPGA_REG1@h /* set offset for FPGA_REG1 */ - ori r5,r5,FPGA_REG1@l - lbz r5,0x0(r5) /* read to get PCI arb selection */ - andi. r6,r5,FPGA_REG1_PCI_INT_ARB /* using internal arbiter ?*/ - beq ..pci_cfg_set /* if not set, then bypass reg write*/ -#endif - ori r3,r3,CPC0_PCI_ARBIT_EN -..pci_cfg_set: - mtdcr CPC0_PCI, r3 /* Enable internal arbiter*/ - - /* - !----------------------------------------------------------------------- - ! Check to see if chip is in bypass mode. - ! If so, write stored CPC0_PLLMR0 and CPC0_PLLMR1 values and perform a - ! CPU reset Otherwise, skip this step and keep going. - ! Note: Running BIOS in bypass mode is not supported since PLB speed - ! will not be fast enough for the SDRAM (min 66MHz) - !----------------------------------------------------------------------- - */ - mfdcr r5, CPC0_PLLMR1 - rlwinm r4,r5,1,0x1 /* get system clock source (SSCS) */ - cmpi cr0,0,r4,0x1 - - beq pll_done /* if SSCS =b'1' then PLL has */ - /* already been set */ - /* and CPU has been reset */ - /* so skip to next section */ - -#ifdef CONFIG_BUBINGA405EP - /* - !----------------------------------------------------------------------- - ! Read NVRAM to get value to write in PLLMR. - ! If value has not been correctly saved, write default value - ! Default config values (assuming on-board 33MHz SYS_CLK) are above. - ! See CPU_DEFAULT_200 and CPU_DEFAULT_266 above. - ! - ! WARNING: This code assumes the first three words in the nvram_t - ! structure in openbios.h. Changing the beginning of - ! the structure will break this code. - ! - !----------------------------------------------------------------------- - */ - addis r3,0,NVRAM_BASE@h - addi r3,r3,NVRAM_BASE@l - - lwz r4, 0(r3) - addis r5,0,NVRVFY1@h - addi r5,r5,NVRVFY1@l - cmp cr0,0,r4,r5 /* Compare 1st NVRAM Magic number*/ - bne ..no_pllset - addi r3,r3,4 - lwz r4, 0(r3) - addis r5,0,NVRVFY2@h - addi r5,r5,NVRVFY2@l - cmp cr0,0,r4,r5 /* Compare 2 NVRAM Magic number */ - bne ..no_pllset - addi r3,r3,8 /* Skip over conf_size */ - lwz r4, 4(r3) /* Load PLLMR1 value from NVRAM */ - lwz r3, 0(r3) /* Load PLLMR0 value from NVRAM */ - rlwinm r5,r4,1,0x1 /* get system clock source (SSCS) */ - cmpi cr0,0,r5,1 /* See if PLL is locked */ - beq pll_write -..no_pllset: -#endif /* CONFIG_BUBINGA405EP */ - - addis r3,0,PLLMR0_DEFAULT@h /* PLLMR0 default value */ - ori r3,r3,PLLMR0_DEFAULT@l /* */ - addis r4,0,PLLMR1_DEFAULT@h /* PLLMR1 default value */ - ori r4,r4,PLLMR1_DEFAULT@l /* */ - - b pll_write /* Write the CPC0_PLLMR with new value */ - -pll_done: - /* - !----------------------------------------------------------------------- - ! Clear Soft Reset Register - ! This is needed to enable PCI if not booting from serial EPROM - !----------------------------------------------------------------------- - */ - addi r3, 0, 0x0 - mtdcr CPC0_SRR, r3 - - addis r3,0,0x0010 - mtctr r3 -pci_wait: - bdnz pci_wait - - blr /* return to main code */ - -/* -!----------------------------------------------------------------------------- -! Function: pll_write -! Description: Updates the value of the CPC0_PLLMR according to CMOS27E documentation -! That is: -! 1. Pll is first disabled (de-activated by putting in bypass mode) -! 2. PLL is reset -! 3. Clock dividers are set while PLL is held in reset and bypassed -! 4. PLL Reset is cleared -! 5. Wait 100us for PLL to lock -! 6. A core reset is performed -! Input: r3 = Value to write to CPC0_PLLMR0 -! Input: r4 = Value to write to CPC0_PLLMR1 -! Output r3 = none -!----------------------------------------------------------------------------- -*/ -pll_write: - mfdcr r5, CPC0_UCR - andis. r5,r5,0xFFFF - ori r5,r5,0x0101 /* Stop the UART clocks */ - mtdcr CPC0_UCR,r5 /* Before changing PLL */ - - mfdcr r5, CPC0_PLLMR1 - rlwinm r5,r5,0,0x7FFFFFFF /* Disable PLL */ - mtdcr CPC0_PLLMR1,r5 - oris r5,r5,0x4000 /* Set PLL Reset */ - mtdcr CPC0_PLLMR1,r5 - mtdcr CPC0_PLLMR0,r3 /* Set clock dividers */ - rlwinm r5,r4,0,0x3FFFFFFF /* Reset & Bypass new PLL dividers */ - oris r5,r5,0x4000 /* Set PLL Reset */ - mtdcr CPC0_PLLMR1,r5 /* Set clock dividers */ - rlwinm r5,r5,0,0xBFFFFFFF /* Clear PLL Reset */ - mtdcr CPC0_PLLMR1,r5 - - /* - ! Wait min of 100us for PLL to lock. - ! See CMOS 27E databook for more info. - ! At 200MHz, that means waiting 20,000 instructions - */ - addi r3,0,20000 /* 2000 = 0x4e20 */ - mtctr r3 -pll_wait: - bdnz pll_wait + lis r4, DCACHE_RAM_BASE@ha + addi r4, r4, DCACHE_RAM_BASE@l + srwi r4, r4, 27 + li r0, 1 + slw r4, r0, r4 + nor r0, r4, r4 + mtdcr dcwr, r0 /* data cache write-back */ + mtdccr r4 /* data cache enable */ + sync - oris r5,r5,0x8000 /* Enable PLL */ - mtdcr CPC0_PLLMR1,r5 /* Engage */ + /* DMA Status, clear to come up clean */ - /* - * Reset CPU to guarantee timings are OK - * Not sure if this is needed... - */ - addis r3,0,0x1000 - mtspr dbcr0,r3 /* This will cause a CPU core reset, and */ - /* execution will continue from the poweron */ - /* vector of 0xfffffffc */ -#endif /* CONFIG_405EP */ -#endif + addis r3,r0, 0xFFFF /* Clear all existing DMA status */ + ori r3,r3, 0xFFFF + mtdcr dmasr, r3 |