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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libbsp/] [m68k/] [gen68340/] [start/] [start.S] - Rev 173
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/** This file contains the entry point for the application.* The name of this entry point is compiler dependent.* It jumps to the BSP which is responsible for performing* all initialization.** COPYRIGHT (c) 1989-1999.* On-Line Applications Research Corporation (OAR).** The license and distribution terms for this file may in* the file LICENSE in this distribution or at* http://www.OARcorp.com/rtems/license.html.** Based on the `gen68360' board support package, and covered by the* original distribution terms.** Geoffroy Montel* France Telecom - CNET/DSM/TAM/CAT* 4, rue du Clos Courtel* 35512 CESSON-SEVIGNE* FRANCE** e-mail: g_montel@yahoo.com** $Id: start.S,v 1.2 2001-09-27 12:00:07 chris Exp $*/#include "asm.h"#include <m68349.inc>#define _OLD_ASTECC 1 /* old addresses for AST68340 only, undefine for AST68349 */BEGIN_CODE/** Step 1: Decide on Reset Stack Pointer and Initial Program Counter*/Entry:.long SYM(m340)+1024 | 0: Initial SSP.long start | 1: Initial PC.long SYM(_uhoh) | 2: Bus error.long SYM(_uhoh) | 3: Address error.long SYM(_uhoh) | 4: Illegal instruction.long SYM(_uhoh) | 5: Zero division.long SYM(_uhoh) | 6: CHK, CHK2 instruction.long SYM(_uhoh) | 7: TRAPcc, TRAPV instructions.long SYM(_uhoh) | 8: Privilege violation.long SYM(_uhoh) | 9: Trace.long SYM(_uhoh) | 10: Line 1010 emulator.long SYM(_uhoh) | 11: Line 1111 emulator.long SYM(_uhoh) | 12: Hardware breakpoint.long SYM(_uhoh) | 13: Reserved for coprocessor violation.long SYM(_uhoh) | 14: Format error.long SYM(_uhoh) | 15: Uninitialized interrupt.long SYM(_uhoh) | 16: Unassigned, reserved.long SYM(_uhoh) | 17:.long SYM(_uhoh) | 18:.long SYM(_uhoh) | 19:.long SYM(_uhoh) | 20:.long SYM(_uhoh) | 21:.long SYM(_uhoh) | 22:.long SYM(_uhoh) | 23:.long SYM(_spuriousInterrupt) | 24: Spurious interrupt.long SYM(_uhoh) | 25: Level 1 interrupt autovector.long SYM(_uhoh) | 26: Level 2 interrupt autovector.long SYM(_uhoh) | 27: Level 3 interrupt autovector.long SYM(_uhoh) | 28: Level 4 interrupt autovector.long SYM(_uhoh) | 29: Level 5 interrupt autovector.long SYM(_uhoh) | 30: Level 6 interrupt autovector.long SYM(_uhoh) | 31: Level 7 interrupt autovector.long SYM(_uhoh) | 32: Trap instruction (0-15).long SYM(_uhoh) | 33:.long SYM(_uhoh) | 34:.long SYM(_uhoh) | 35:.long SYM(_uhoh) | 36:.long SYM(_uhoh) | 37:.long SYM(_uhoh) | 38:.long SYM(_uhoh) | 39:.long SYM(_uhoh) | 40:.long SYM(_uhoh) | 41:.long SYM(_uhoh) | 42:.long SYM(_uhoh) | 43:.long SYM(_uhoh) | 44:.long SYM(_uhoh) | 45:.long SYM(_uhoh) | 46:.long SYM(_uhoh) | 47:.long SYM(_uhoh) | 48: Reserved for coprocessor.long SYM(_uhoh) | 49:.long SYM(_uhoh) | 50:.long SYM(_uhoh) | 51:.long SYM(_uhoh) | 52:.long SYM(_uhoh) | 53:.long SYM(_uhoh) | 54:.long SYM(_uhoh) | 55:.long SYM(_uhoh) | 56:.long SYM(_uhoh) | 57:.long SYM(_uhoh) | 58:.long SYM(_uhoh) | 59: Unassigned, reserved.long SYM(_uhoh) | 60:.long SYM(_uhoh) | 61:.long SYM(_uhoh) | 62:.long SYM(_uhoh) | 63:.long SYM(_uhoh) | 64: User defined vectors (192).long SYM(_uhoh) | 65:.long SYM(_uhoh) | 66:.long SYM(_uhoh) | 67:.long SYM(_uhoh) | 68:.long SYM(_uhoh) | 69:.long SYM(_uhoh) | 70:.long SYM(_uhoh) | 71:.long SYM(_uhoh) | 72:.long SYM(_uhoh) | 73:.long SYM(_uhoh) | 74:.long SYM(_uhoh) | 75:.long SYM(_uhoh) | 76:.long SYM(_uhoh) | 77:.long SYM(_uhoh) | 78:.long SYM(_uhoh) | 79:.long SYM(_uhoh) | 80:.long SYM(_uhoh) | 81:.long SYM(_uhoh) | 82:.long SYM(_uhoh) | 83:.long SYM(_uhoh) | 84:.long SYM(_uhoh) | 85:.long SYM(_uhoh) | 86:.long SYM(_uhoh) | 87:.long SYM(_uhoh) | 88:.long SYM(_uhoh) | 89:.long SYM(_uhoh) | 90:.long SYM(_uhoh) | 91:.long SYM(_uhoh) | 92:.long SYM(_uhoh) | 93:.long SYM(_uhoh) | 94:.long SYM(_uhoh) | 95:.long SYM(_uhoh) | 96:.long SYM(_uhoh) | 97:.long SYM(_uhoh) | 98:.long SYM(_uhoh) | 99:.long SYM(_uhoh) | 100:.long SYM(_uhoh) | 101:.long SYM(_uhoh) | 102:.long SYM(_uhoh) | 103:.long SYM(_uhoh) | 104:.long SYM(_uhoh) | 105:.long SYM(_uhoh) | 106:.long SYM(_uhoh) | 107:.long SYM(_uhoh) | 108:.long SYM(_uhoh) | 109:.long SYM(_uhoh) | 110:.long SYM(_uhoh) | 111:.long SYM(_uhoh) | 112:.long SYM(_uhoh) | 113:.long SYM(_uhoh) | 114:.long SYM(_uhoh) | 115:.long SYM(_uhoh) | 116:.long SYM(_uhoh) | 117:.long SYM(_uhoh) | 118:.long SYM(_uhoh) | 119:.long SYM(_uhoh) | 120:.long SYM(_uhoh) | 121:.long SYM(_uhoh) | 122:.long SYM(_uhoh) | 123:.long SYM(_uhoh) | 124:.long SYM(_uhoh) | 125:.long SYM(_uhoh) | 126:.long SYM(_uhoh) | 127:.long SYM(_uhoh) | 128:.long SYM(_uhoh) | 129:.long SYM(_uhoh) | 130:.long SYM(_uhoh) | 131:.long SYM(_uhoh) | 132:.long SYM(_uhoh) | 133:.long SYM(_uhoh) | 134:.long SYM(_uhoh) | 135:.long SYM(_uhoh) | 136:.long SYM(_uhoh) | 137:.long SYM(_uhoh) | 138:.long SYM(_uhoh) | 139:.long SYM(_uhoh) | 140:.long SYM(_uhoh) | 141:.long SYM(_uhoh) | 142:.long SYM(_uhoh) | 143:.long SYM(_uhoh) | 144:.long SYM(_uhoh) | 145:.long SYM(_uhoh) | 146:.long SYM(_uhoh) | 147:.long SYM(_uhoh) | 148:.long SYM(_uhoh) | 149:.long SYM(_uhoh) | 150:.long SYM(_uhoh) | 151:.long SYM(_uhoh) | 152:.long SYM(_uhoh) | 153:.long SYM(_uhoh) | 154:.long SYM(_uhoh) | 155:.long SYM(_uhoh) | 156:.long SYM(_uhoh) | 157:.long SYM(_uhoh) | 158:.long SYM(_uhoh) | 159:.long SYM(_uhoh) | 160:.long SYM(_uhoh) | 161:.long SYM(_uhoh) | 162:.long SYM(_uhoh) | 163:.long SYM(_uhoh) | 164:.long SYM(_uhoh) | 165:.long SYM(_uhoh) | 166:.long SYM(_uhoh) | 167:.long SYM(_uhoh) | 168:.long SYM(_uhoh) | 169:.long SYM(_uhoh) | 170:.long SYM(_uhoh) | 171:.long SYM(_uhoh) | 172:.long SYM(_uhoh) | 173:.long SYM(_uhoh) | 174:.long SYM(_uhoh) | 175:.long SYM(_uhoh) | 176:.long SYM(_uhoh) | 177:.long SYM(_uhoh) | 178:.long SYM(_uhoh) | 179:.long SYM(_uhoh) | 180:.long SYM(_uhoh) | 181:.long SYM(_uhoh) | 182:.long SYM(_uhoh) | 183:.long SYM(_uhoh) | 184:.long SYM(_uhoh) | 185:.long SYM(_uhoh) | 186:.long SYM(_uhoh) | 187:.long SYM(_uhoh) | 188:.long SYM(_uhoh) | 189:.long SYM(_uhoh) | 190:.long SYM(_uhoh) | 191:.long SYM(_uhoh) | 192:.long SYM(_uhoh) | 193:.long SYM(_uhoh) | 194:.long SYM(_uhoh) | 195:.long SYM(_uhoh) | 196:.long SYM(_uhoh) | 197:.long SYM(_uhoh) | 198:.long SYM(_uhoh) | 199:.long SYM(_uhoh) | 200:.long SYM(_uhoh) | 201:.long SYM(_uhoh) | 202:.long SYM(_uhoh) | 203:.long SYM(_uhoh) | 204:.long SYM(_uhoh) | 205:.long SYM(_uhoh) | 206:.long SYM(_uhoh) | 207:.long SYM(_uhoh) | 208:.long SYM(_uhoh) | 209:.long SYM(_uhoh) | 210:.long SYM(_uhoh) | 211:.long SYM(_uhoh) | 212:.long SYM(_uhoh) | 213:.long SYM(_uhoh) | 214:.long SYM(_uhoh) | 215:.long SYM(_uhoh) | 216:.long SYM(_uhoh) | 217:.long SYM(_uhoh) | 218:.long SYM(_uhoh) | 219:.long SYM(_uhoh) | 220:.long SYM(_uhoh) | 221:.long SYM(_uhoh) | 222:.long SYM(_uhoh) | 223:.long SYM(_uhoh) | 224:.long SYM(_uhoh) | 225:.long SYM(_uhoh) | 226:.long SYM(_uhoh) | 227:.long SYM(_uhoh) | 228:.long SYM(_uhoh) | 229:.long SYM(_uhoh) | 230:.long SYM(_uhoh) | 231:.long SYM(_uhoh) | 232:.long SYM(_uhoh) | 233:.long SYM(_uhoh) | 234:.long SYM(_uhoh) | 235:.long SYM(_uhoh) | 236:.long SYM(_uhoh) | 237:.long SYM(_uhoh) | 238:.long SYM(_uhoh) | 239:.long SYM(_uhoh) | 240:.long SYM(_uhoh) | 241:.long SYM(_uhoh) | 242:.long SYM(_uhoh) | 243:.long SYM(_uhoh) | 244:.long SYM(_uhoh) | 245:.long SYM(_uhoh) | 246:.long SYM(_uhoh) | 247:.long SYM(_uhoh) | 248:.long SYM(_uhoh) | 249:.long SYM(_uhoh) | 250:.long SYM(_uhoh) | 251:.long SYM(_uhoh) | 252:.long SYM(_uhoh) | 253:.long SYM(_uhoh) | 254:.long SYM(_uhoh) | 255:/** Default trap handler* With an oscilloscope you can see AS* stop*/PUBLIC (_uhoh)SYM(_uhoh): nop | Leave spot for breakpoint/* stop #0x2700 | Stop with interrupts disabled */move.w #0x2700,srmove.w (a7),_boot_panic_registers+4 | SRmove.l 2(a7),_boot_panic_registers | PCmove.w 6(a7),_boot_panic_registers+6 | format & vectormovem.l d0-d7/a0-a7, _boot_panic_registers+8movec sfc, d0movem.l d0, _boot_panic_registers+72movec dfc, d0movem.l d0, _boot_panic_registers+76movec vbr, d0movem.l d0, _boot_panic_registers+80jmp SYM(_dbug_dumpanic)bra.s _crt0_cold_start/** Log, but otherwise ignore, spurious interrupts*/PUBLIC (_spuriousInterrupt)SYM(_spuriousInterrupt):addql #1,SYM(_M68kSpuriousInterruptCount)rte/** Place the low-order 3 octets of the board's ethernet address at* a `well-known' fixed location relative to the startup location.*/.align 2.word 0 | Paddingethernet_address_buffer:.word 0x08F3 | Default address.word 0xDEAD.word 0xCAFEBEGIN_DATA/* equates */.equ _CPU340, 0x0.equ _CPU349, 0x31#ifdef _OLD_ASTECC /* old addresses for AST68340 only */.equ _EPLD_CS_BASE, 0x1.equ _PROM_Start, 0x01000000 /* CS0 */.equ _FLEX_Start, 0x08000000 /* CS2 */.equ _I2C_Start, 0x0c000000 /* CS3 */.equ _BCCram_Start, 0x00000000 /* CS1 64 Kbytes */.equ _BCCram_Size, 0x00010000 /* CS1 64 Kbytes */.equ _ExtRam_Start, 0x10000000 /* SRAM */.equ _ExtRam_Size, 0x00400000 /* 4 Mbytes */.equ _FastRam_Start, 0x00000000 /* overlap /CS1 for the first 4 Kbytes */.equ _FastRam_Size, 0x00001000 /* 4 Kbytes */#else /* new addresses for AST68349 and 68340 */.equ _EPLD_CS_BASE, 0x5.equ _PROM_Start, 0x50000000 /* CS0 */.equ _FLEX_Start, 0x08000000 /* CS2 */.equ _I2C_Start, 0x0c000000 /* CS3 */.equ _BCCram_Start, 0x00000000 /* CS1 64 Kbytes */.equ _BCCram_Size, 0x00010000 /* CS1 64 Kbytes */.equ _ExtRam_Start, 0x80000000 /* DRAM */.equ _ExtRam_Size, 0x00400000 /* 4 Mbytes */.equ _FastRam_Start, 0x00000000 /* overlap /CS1 for the first 4 Kbytes */.equ _FastRam_Size, 0x00001000 /* 4 Kbytes */#endif.equ _SPEED349, 0xD680 /* 24 Mhz */.equ _SPEED340, 0xD700 /* 25 Mhz *//* .equ _SPEED340, 0xCE00 16 Mhz */#define crt0_boot_type d0 /* cold/warm start (must be D0) */#define crt0_temp d1#define crt0_cpu_type d2#define crt0_csswitch d3#define crt0_buswidth d4#define crt0_pdcs d5#define crt0_spare6 d6#define crt0_spare7 d7#define crt0_sim_base a0#define crt0_glue a1#define crt0_dram a2#define crt0_ptr3 a3#define crt0_ptr4 a4#define crt0_ptr5 a5#define crt0_ptr6 a6/* -- PDCS buffer equates -- */.equ pdcs_mask, 0x1F /* DRAM configuration */.equ pdcs_sw12, 7 /* switch 12 */.equ pdcs_sw11, 6 /* switch 11 */.equ pdcs_sw14, 5 /* switch 14 */.equ bit_cache, pdcs_sw12 /* enable cache if on */.equ bit_meminit, pdcs_sw11 /* init memory if on *//* -- Initialization stack and vars -- */_AsteccBusWidth: ds.b 1_AsteccCsSwitch: ds.b 1_AsteccCpuName: ds.l 1.align 4_crt0_init_stack:ds.l 500_crt0_init_stktop:/* -- Initialization code -- */BEGIN_CODE.align 4dc.l _crt0_init_stktop /* reset SP */dc.l _crt0_cold_start /* reset PC */dc.l _crt0_warm_start.ascii "BOOT XHM68K/Spectra for ASTECC 68349 and 68340 boards"dc.w 0.align 4.globl startstart:_crt0_cold_start:moveq.l #0,crt0_boot_type | signal cold resetbra.s _crt0_common_start_crt0_warm_start:moveq.l #1,crt0_boot_type | signal warm reset_crt0_common_start:move.w #0x2700,sr | disable interrupts and switch to interrupt modemovea.l #_crt0_init_stktop,sp | set up initialization stackmove.l #Entry,crt0_temp | VBR initializationmovec.l crt0_temp,vbr |moveq.l #0x07,crt0_tempmovec.l crt0_temp,dfc | prepare access in CPU spacemove.l #(BASE_SIM+0x111),crt0_temp | mask CPU, RESERVED USER SPACESmoves.l crt0_temp,BASE_REG | base initialization (must be MOVES, PCC-130795)movea.l #BASE_SIM,crt0_sim_base/* -- disable Bus Monitor -- */move.b #0,SIM_SYPCR(crt0_sim_base) | system protection control register/* -- enable A31-A24 -- */clr.b SIM_PPRA1(crt0_sim_base)/* -- show cycles, user acces to SIM, 4 /CS & 4 /IT -- */move.w #0x427F,SIM_MCR(crt0_sim_base)/* -- enable /IRQ3, 5, 6, 7 -- */move.b #0xE8,SIM_PPRB(crt0_sim_base)/* -- enable autovector on /IRQ7 -- */move.b #0x80,SIM_AVR(crt0_sim_base)/* -- test CPU type -- */cmp.b #_CPU349,SIM_IDR(crt0_sim_base)bne cpu_is_68340/*-------------------------------------------------------------------------------------------*/cpu_is_68349:/* -- set cpu clock -- */move.w #_SPEED349,SIM_SYNCR(crt0_sim_base) | clocksync_wait349:btst.b #3,(SIM_SYNCR+1)(crt0_sim_base)beq sync_wait349/* to allow access to the EPLD internal registers, it is necessaryto disable the global chip-select /CS0 (which decodes every externalcycles). To do that, we initialize the 68349 internal RAM,copy a part of the initialization code in it, and jump there.from that moment, /CS0 is not used, therefore it can be initializedwith its default value. Its width may be incorrect, but it will beadjusted later. The goal is to avoid any conflict withthe accesses to the EPLD registers.When this is done, we read the RESET parameters (boot prom widthand chip-select switch) and proceed with the initializationwhen all is done, we jump back to the boot prom nowdecoded with a properly configured /CS0 *//*-------------------------------------*//* -- configure internal SRAM banks -- */move.l #0x00000000,QDMM_MCR(crt0_sim_base)move.l #_FastRam_Start+0x0005,QDMM_QBAR0(crt0_sim_base)move.l #_FastRam_Start+0x0405,QDMM_QBAR1(crt0_sim_base)move.l #_FastRam_Start+0x0805,QDMM_QBAR2(crt0_sim_base)move.l #_FastRam_Start+0x0c05,QDMM_QBAR3(crt0_sim_base)/*--------------------------------------------------------*//* -- copy to address of the 68349 initialization code -- */lea.l _copy_start_code(%pc),crt0_ptr3lea.l _copy_end_code(%pc),crt0_ptr4move.l crt0_ptr4,crt0_tempsub.l crt0_ptr3,crt0_tempadd.l #3,crt0_temp | adjust to next long wordlsr.l #2,crt0_tempmove.l #_FastRam_Start,crt0_ptr4_copy_loop:move.l (crt0_ptr3)+,(crt0_ptr4)+subq.l #1,crt0_tempbne.s _copy_loopbra.l _FastRam_Start | jump to code in internal RAM/*------------------------------------*//* -- start of initialization code -- */_copy_start_code:bra.l _begin_68349_init/*----------------------------------------------------------*//* Astecc 68349 board : chip-select initialization values */_table_csepld:dc.b (_EPLD_CS_BASE&0x0F)+0x80 | 16 bits, 0wsdc.b 0x80 | 16 bits, 0 wsdc.b 0x90 | 16 bits, ext /dsackdc.b 0x90 | 16 bits, ext /dsack_table_cs349:dc.l 0x003FFFF4 | Mask CS0 (4Mbytes PROM, 32bits, 1WS)dc.l (_PROM_Start&0xFFFFFF00)+0x00000003 | Base CS0dc.l 0x003FFFF1 | MASK CS1 (4Mbytes RAM, 16bits, 0WS)dc.l (_BCCram_Start&0xFFFFFF00)+0x00000003 | Base CS1dc.l 0x000000FF | MASK CS2 (FLEX, ext DTACK, 256 bytes)dc.l (_FLEX_Start&0xFFFFFF00)+0x00000003 | Base CS2dc.l 0x000000FF | Mask CS3 (I2C, ext DTACK, 256 bytes)dc.l (_I2C_Start&0xFFFFFF00)+0x00000003 | Base CS3/*-------------------------------------------------*/_begin_68349_init:/*-------------------------------------------------*//* 68349 chip select initializationat this stage, the width of /CS0 may be incorrectit will be corrected later*/_cs68349_init:lea.l SIM_MASKH0(crt0_sim_base),crt0_ptr4lea.l _table_cs349(%pc),crt0_ptr3moveq.l #0x07,crt0_temp_cs349_init2:move.l (crt0_ptr3)+,(crt0_ptr4)+dbra crt0_temp,_cs349_init2/*-----------------------------------------------*//* -- prepare access to the internal registers --*/moveq.l #EPLD_SPACE,crt0_tempmovec.l crt0_temp,dfcmovec.l crt0_temp,sfcmove.l #GLUE_EPLD,crt0_gluemove.l #DRAM_EPLD,crt0_dram/*-------------------------------------------*//* EPLD generated /CS[3..0] must be disabled */_csepld_clear:move.l crt0_glue,crt0_ptr4move.w #3,crt0_spare6clr.b crt0_temp_csepld_clear1:moves.b crt0_temp,(crt0_ptr4)+dbra crt0_spare6,_csepld_clear1/*---------------------------------------------------------*//* -- get width of boot PROM, and active chip-select set --*/moves.b REG_BUSWIDTH(crt0_dram),crt0_csswitchmove.b crt0_csswitch,crt0_buswidth/* state of CS_SWITCH : sel == 0 => CPU chip_selects (/CS[3..0]): sel == 1 => EPLD chip_selects (/CS[3..0]) */and.b #1,crt0_csswitch/* bus width of /CS0 during reset bw[1..0] : 0 1 2 3bus width : 32 16 8 ext./dsackx */rol.b #2,crt0_buswidthand.b #3,crt0_buswidth/*----------------------------------------------------*//* -- configure chip select 0 with boot prom width -- */lea.l SIM_MASKH0(crt0_sim_base),crt0_ptr4lea.l _table_cs349(%pc),crt0_ptr3move.l (crt0_ptr3)+,crt0_tempand.b #0xFC,crt0_temp | clear PS0 & PS1or.b crt0_buswidth,crt0_temp | set boot PROM bus widthmove.l crt0_temp,(crt0_ptr4)+/*------------------------*//* -- read PDCS buffer -- */moves.b REG_PDCS(crt0_glue),crt0_pdcs/* move.b #0x3F,crt0_pdcs pour test *//*---------------------------------------*//* -- EPLD chip-select initialization -- *//*---------------------------------------*/btst.b #0,crt0_csswitchbeq _cs_init_end/*--------------------------------------------*//* 68349 generated /CS[3..0] must be disabled */lea.l SIM_MASKH0(crt0_sim_base),crt0_ptr4lea.l _table_cs349(%pc),crt0_ptr3moveq.l #0x03,crt0_temp_cs349_clear:move.l (crt0_ptr3)+,(crt0_ptr4)+move.l (crt0_ptr3)+,crt0_spare6and.b #0xFE,crt0_spare6 | disable chip-selectmove.l crt0_spare6,(crt0_ptr4)+dbra crt0_temp,_cs349_clear/*---------------------------------------------*//* EPLD generated /CS[3..0] must be configured */_csepld_init:move.l crt0_glue,crt0_ptr4lea.l _table_csepld(%pc),crt0_ptr3move.b (crt0_ptr3)+,crt0_tempor.b #0x20,crt0_temp | default width is 32 bitstst.b crt0_buswidth | is boot PROM bus width 32 bits ?beq _csepld1 | if notand.b #0xDF,crt0_temp | set width to 16 bits_csepld1:moves.b crt0_temp,(crt0_ptr4)+moveq.l #0x02,crt0_spare6_csepld2:move.b (crt0_ptr3)+,crt0_tempmoves.b crt0_temp,(crt0_ptr4)+dbra crt0_spare6,_csepld2_cs_init_end:/*--------------------------------------*//* -- DRAM controller initialization -- */_dram_init:move.w #15,crt0_tempmove.l #_ExtRam_Start,crt0_ptr3_dram_init1:clr.l (crt0_ptr3)+ | must access DRAMdbra crt0_temp,_dram_init1 | prior to init refresh_dram_init2:move.b #3,crt0_tempmoves.b crt0_temp,REG_WS(crt0_dram) | set 3 wait-statesmove.b #0x81,crt0_tempmove.b #0,crt0_tempmoves.b crt0_temp,REG_CONFIG(crt0_dram) | default size = 4Mbytes/*-----------------------*//* -- configure cache -- */_init_cache:move.l #0x000001E0,CACHE_MCR(crt0_sim_base)btst.b #bit_cache,crt0_pdcsbne _init_cache_endor.l #0x00000001,CACHE_MCR(crt0_sim_base)_init_cache_end:/*-----------------------------*//* -- timers initialization -- */clr.b crt0_tempmoves.b crt0_temp,REG_TIMER1(crt0_glue) | disable timer 1moves.b crt0_temp,REG_TIMER2(crt0_glue) | disable timer 2/*--------------------------*//* -- I2C initialization -- */move.b #3,crt0_tempmoves.b crt0_temp,REG_I2C(crt0_glue) | tri-states I2C ports/*-----------------------------------------*//* -- baudrate generator initialization -- */move.b #2,crt0_tempmoves.b crt0_temp,REG_BAUDRATE(crt0_glue) | baudrate = 38400/*-------------------------------*//* -- IO port initialization -- */clr.b crt0_tempmoves.b crt0_temp,REG_IO(crt0_glue) | set port as input/* -- */move.l #68349,crt0_cpu_type/* -- jump back to PROM -- */jmp.l (_fill_test) | must be absolute long_copy_end_code:/*-------------------------------------------------initialization code for the 68340 board-------------------------------------------------*//* Astecc 68340 board : chip-select initialization values */_table_cs340:dc.l 0x003FFFF0 /* Mask CS0 (4Mbytes PROM, 32bits, 0WS) */dc.l ((_PROM_Start&0xFFFFFF00)+0x00000003) /* Base CS0 */dc.l 0x0000FFFD /* MASK CS1 (RAMBCC340, 0WS, FTE) */dc.l ((_BCCram_Start&0xFFFFFF00)+0x00000003) /* Base CS1 */dc.l 0x000000FF /* MASK CS2 (FLEX, ext DTACK, 256 bytes) */dc.l ((_FLEX_Start&0xFFFFFF00)+0x00000003) /* Base CS2 */dc.l 0x000000FF /* Mask CS3 (I2C, ext DTACK, 256 bytes) */dc.l ((_I2C_Start&0xFFFFFF00)+0x00000003) /* Base CS3 */cpu_is_68340:/* -- set cpu clock -- */move.w #_SPEED340,SIM_SYNCR(crt0_sim_base) | clocksync_wait340:btst.b #3,(SIM_SYNCR+1)(crt0_sim_base)beq sync_wait340/* -- chip select initialization -- */lea.l SIM_MASKH0(crt0_sim_base),crt0_ptr4lea.l _table_cs340(%pc),crt0_ptr3moveq.l #0x07,crt0_temp_b_cs340:move.l (crt0_ptr3)+,crt0_ptr5move.l crt0_ptr5,(crt0_ptr4)+ | pour testdbra crt0_temp,_b_cs340move.l #68340,crt0_cpu_typemove.b #0,crt0_csswitch | CPUmove.b #1,crt0_buswidth | 16 bits/*-------------------------------------------------fill RAM if COLDSTART-------------------------------------------------*/_fill_test:tst.l crt0_boot_typebne _dont_fillcmp.b #_CPU349,SIM_IDR(crt0_sim_base)bne _fillbtst.b #bit_meminit,crt0_pdcsbne _dont_fill/* fill main memory */_fill:move.l #_crt0_init_stack,crt0_ptr3 | skip Astecc varsmove.l #_ExtRam_Start,crt0_tempsub.l #_crt0_init_stack,crt0_tempadd.l #_ExtRam_Size,crt0_temp | get sizelsr.l #2,crt0_temp | ajust for long word_fill_loop:clr.l (crt0_ptr3)+subq.l #1,crt0_tempbne _fill_loopcmp.b #_CPU349,SIM_IDR(crt0_sim_base)bne _fill_bccram/* fill QDMM memory */movea.l #_FastRam_Start,crt0_ptr3 | get startmove.l #_FastRam_Size,crt0_temp | get sizelsr.l #2,crt0_temp | ajust for long word_QDMMfill_loop:clr.l (crt0_ptr3)+subq.l #1,crt0_tempbne _QDMMfill_loopbra _dont_fill/* fill BCC memory */_fill_bccram:movea.l #_BCCram_Start,crt0_ptr3 | get startmove.l #_BCCram_Size,crt0_temp | get sizelsr.l #2,crt0_temp | ajust for long word_BCCfill_loop:clr.l (crt0_ptr3)+subq.l #1,crt0_tempbne _BCCfill_loop*-------------------------------------------------*/_dont_fill:move.b crt0_csswitch,_AsteccCsSwitchmove.b crt0_buswidth,_AsteccBusWidthmove.l crt0_cpu_type,_AsteccCpuNamejmp SYM(_Init68340) | Start C code (which never returns)/** Copy DATA segment, clear BSS segment, set up real stack,* initialize heap, start C program.* Assume that DATA and BSS sizes are multiples of 4.*/PUBLIC (_CopyDataClearBSSAndStart)SYM(_CopyDataClearBSSAndStart):lea SYM(_copy_start),a0 | Get start of DATA in RAMlea SYM(_etext),a2 | Get start of DATA in ROMcmpl a0,a2 | Are they the same?beq.s NOCOPY | Yes, no copy necessarylea SYM(_copy_end),a1 | Get end of DATA in RAMbra.s COPYLOOPTEST | Branch into copy loopCOPYLOOP:movel a2@+,a0@+ | Copy word from ROM to RAMCOPYLOOPTEST:cmpl a1,a0 | Done?bcs.s COPYLOOP | No, skipNOCOPY:lea _clear_start,a0 | Get start of BSSlea _clear_end,a1 | Get end of BSSclrl d0 | Value to setbra.s ZEROLOOPTEST | Branch into clear loopZEROLOOP:movel d0,a0@+ | Clear a wordZEROLOOPTEST:cmpl a1,a0 | Done?bcs.s ZEROLOOP | No, skipmovel #_stack_init,a7 | set master stack pointermovel d0,a7@- | environpmovel d0,a7@- | argvmovel d0,a7@- | argcjsr SYM(boot_card) | Call C mainPUBLIC (_mainDone)SYM(_mainDone):nop | Leave spot for breakpointmovew #1,a7 | Force a double bus errormovel d0,a7@- | This should cause a RESET/* stop #0x2700 | Stop with interrupts disabled */move.w #0x2700,srbra.l SYM(_mainDone) | Stuck forever.align 2BEGIN_DATA_DCL.align 2PUBLIC (environ)SYM (environ):.long 0PUBLIC (_M68kSpuriousInterruptCount)SYM (_M68kSpuriousInterruptCount):.long 0END_DATA_DCLEND