ncr710init.n

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; ncr710init.n Script code for ncr710Lib Driver 
;
;START_DOC
;/* ncr710init.c - script programs for the NCR 710 */
;
;/* Copyright 1989-1994 Wind River Systems, Inc. */
;#include "copyright_wrs.h"
;
;/* 
;Modification history
;--------------------
;03f,20jul92,eve    Added documentation. 
;03e,20jul92,eve    Rename end label to endTransact.
;03d,03jul92,eve    Include NCR_COMPILER_BUG in the file.
;03c,04mar92,eve    Start disconnect implementation.
;03b,16jan92,eve    Add ackMsg1 ,ackAtnMsg and endAbort, remove 
;		    script test proc.
;03a,30oct91,eve    Remove int capability in end label,the scsi 
;		    status is process by the ncr710Lib driver.
;02a,26oct91,eve    Add enable disable timout between selection
;		    step.
;01a,23oct91,eve    Created and add comments
;*/
;
;/*
;INTERNAL
;NCR710 FEATURE USED
;This chip has code which performs some action on the scsi bus.
;The description level of the code is close to an assembly language and 
;dedicated for scsi bus operations. 
;The opcode is a pair of 32bit word that allow some basic operations in the 
;code (jump, tests values) and on the scsi (select ,assert line):
;
;block move instruction.
;  move from <offset> when PHASE_NAME
;  ........
;I/O instructions 
;  set target 
;  wait DISCONNECT
;  wait RESELECT
;  select from <offset>,@jump
;  .........  
;read/write register instructions
;  move REG_NAME to SBFR
;  .........  
; 
;transfert control instructions
;  jump <Label> 
;  int <value> when PHASE_NAME
;  ........... 
;  move memory instruction
;  never use.  
; 
;The previous example does not included all of the instruction set, 
;see the NCR data reference manual.
;Another key point is the capability of the script to perform some 
;limited indirect addressing to get information from the cpu memory.
;This is used to get Target ID to select it, to get data, message pointer
;and count during transfer phase.  This avoids having to patch the script
;at the run time to specify count, data pointer and target ID.
;
;Script can tranfer directly, with its DMA core, a data block from/to the 
;scsi bus from/to cpu memory.
;The instruction involved is :
;        move from <offset> when PHASE_NAME
; 
;In this case the offset is hard coded in the ncr710Script.h and indexed the
;right field in the NCR_CTL structure (see ncr710Script1.h). 
; 
;The field looks like :
;    aligned 32 bit @->00xxxxxx  24bit count
;                    ->ZZZZZZZZ  32bit address pointer.
; 
;The offset is added to the content of the DNAD register, loaded at 
;the run time with the base address of the structure.
; 
;In the same way the select instruction uses a field like:
;        select from <offset> ,<Alternate jump @>
;
; where offset + DNAD points to a field like:
;aligned 32 bit@->0000|0000|xxxx xxxx|xPPP  |SSSS|0000|0000
;                           Target ID|Period|Offset
;
;The Period and offset are used when a target supports the synchronous 
;transfert.
;
;INTERRUPT SOURCE
;The chip has three main kind of interrupt, scsi, dma interrupt and 
;script  interrupt.  The scsi interrupts are maskable individually with 
;the sien register.
;.CS
;SIEN
;  7    M/A Mismatch interrupt(initiator)/ ATN assert (Target)
;       Used in the driver to detect a phase change during data/msg
;       transfert.The ncr is never used in target mode.
;  6    FCMP function complete Not used (masked).
;  5    STO scsi Bus Time out
;       Used to get timeout on select.(**)
;  4    SEL selected or reselected Not used in the driver.(masked).
;  3    SGE scsi Gross error. Used in the driver.
;  2    UDC unexpected disconnect.
;       Used to detect unexpected target disconnection or an expected 
;       disconnect if the target received a "device reset message".
;  1    RST scsi reset received (not used).(masked)(***)
;  0    PAR parity error not used.(masked)(***)
;
;(**)    The script disable the timeout capability by setting the bit 7 
;        in CTEST7 register.  Because the ncr will generate also a timeout
;        interrupt  if no activity occur on the scsi bus after 250ms,
;        and not only during a scsi select.
;
;(***)  This case should be processed, but not included in the driver today.
;.CE
;
;The Dma interrupts are maskable with the DIEN register:
;.CS
;DIEN
;  7   Reserved
;  6   Reserved
;  5   BF bus fault.Memory acces error.
;  4   Aborted ,means that the abort bit have been set in ISTAT reg
;      This case never happen (Abort bit not used).
;  3   SSI single step interrupt.Not used in the operational mode.
;      This bit is used in single step debug mode in the driver,
;      allowing to execute script step by step..
;  2   SIR script interrupt,used to detect a script intruction
;      <int ...>.
;  1   WTD Watchdog interrupt.This case never happens because
;      The watchdog timeout value is set to 0 in DWT register.
;  0   IID illegal instruction detected.  Recieved in two
;      cases :1-Bad opcode, 2-count set to 0 in the <move> opcode.
;.CE
;
;The other register involved  in  the  interrupt  process  is ISTAT.
;This register is the ONLY READABLE/WRITABLE  register during a script 
;execution.
;.CS
; ISTAT
; 7   ABRT Abort current instruction.Not used
; 6   RST  software reset used to set the chip to a known state.
; 5   SIGP signal process bit.This bit is used in the ncr driver to support
;     the connect disconnect to get an interrupt to start a new scsi 
;     command.(SEE CONNECT/DISCONNECT ...).
; 4   Reserved.
; 3   Connected ,not used.
; 2   Reserved.
; 1   SIP scsi interrupt pending.Used at interrupt
;     level to detect and clear SIEN interrupt.
; 0   DIP dma interrupt pending.Used at interrupt
;     level to detect and clear DIEN interrupt.
;.CE
;The interrupt are cleared by reading the register source, and by 
;checking  the DIP and SIP bit in ISTAT.  Because the chip has a stack 
;interrupt ,the DIEN and SIEN registers are read until the ISTAT bits 
;are cleared to be sure there is no interrupt pending.
;
;The last interrupt source is the script <INT> opcode. 
;This instruction is  used to interrupt the cpu if the scsi 
;transaction involves a cpu process.
;.CS
;    int <int value> [<condition><value>] (pg 6-10 of the programmers guide).
;.CE
;The <int value> is used in the driver code to detect the scsi condition  
;and takes a decision for the next step of the transaction.  
;This value is loaded from the opcode and read by the  CPU in the 
;DSPS register.
;
;CONNECT/DISCONNECT AND NEW COMMAND START
;
;When connect/disconnect is enabled, the target could reconnect at any time.
;This is notified to the target by an identify message send by the initiator
;after a successful selection of the target.
;The  disconnect is always sent to an initiator by a DISCONNECT message.
;The reconnect could occur at any arbitration phase.  
;To be able to detect it at any time the chip has to wait for a reconnect 
;on the scsi ,which is done with the <wait reconnect> script opcode:
;  wait RECONNECT,<Alternate @>
;  <next opcode>
;.CS
;  If a reconnect occurs, then the <next opcode>
;  is executed.If the SIGP bit is set the script
;  jump to <Alternate @>
;.CE
;
;But a reconnect could also occurs during a  <select>  opcode for  another  
;device (it looses the arbitration).  The <wait RECONNECT> instruction is 
;the idle script entry point.  They are two way to abort this instruction:
;
;  1-The Sigp bit is set
;  2-A reconnect,or a select occur ,in this case
;    select means that the initiator is selected as
;    a target on the scsi bus
;
;The sigp bit is used to detect and start a new command at interrupt level. 
;It is set at task level each time that a new command has to be run.
;
;
;.CS
;SCRIPT START FLOW CHART
;The reselected path is driven by a physical scsi reconnect/select.
;
;IDLE ENTRY POINT
;<waitSelect>
;Wait for a reselect ,Alternate @-------->
;and test sigp ?                         | SIGP set or Select to start
;  |                                     |
;  |<-reselect                           /
;  |                       No    <checkNewCmd>
;  |                     /-------Check if we are connected ?
;<reselect>              |       clear SIGP
;save Targ/init ID       |       Wait for reselect,<@select as a target>
;from LCRC register      |       Jump to <reselect>      |
;Get identify            |                               |
;Msg in.                 <startNewCmd>                   |
;int Cpu <reselected>    test and clear SIGP     int Cpu <SELECT AS A TARGET>
;                        1) SIGP set
;                        int Cpu <NEW COMMAND>
;                        2) SIGP clear
;                        int Cpu <BAD NEW COMD>
;.CE
;a) RESELECT
;At interrupt level, the target ID from the saved LCRC register (LCRC contain
;the data bus value that is <the target ID> | <initiator ID>) and the LUN 
;extracted from the identify message sent by the target are used to index 
;an array that keep track of each PHYS_DEV nexus (Max = 64) in the  SIOP  
;structure (driver structure).
;
;b) NEW COMMAND
;A global variable <pNcrCtlCmd> in the SIOP structure  allows the script to be 
;start at a selected entry point with the script address included in this 
;current nexus pointer in pNcrCtlCmd.
;
;c)SELECT AS A TARGET
;That an error case (we dont support the target  mode)  ,restart script at 
;the IDLE point.
;
;d)BAD NEW CMD
;It's a bogus start command restart script at the IDLE Point.
;
;SCRIPT REMARKS
;This script performs a scsi transaction.  This script is a part of 
;the usual scsi phase routine.  This code is only compatible with the 
;ncr710 because it uses an indirect addressing mode to avoid relocation 
;at run time.
;All of the external values will be relative to the DSA register.
;DSA register has to be loaded whith the address of the ncrCtrl host memory
;structure (see ncr710Script1.h).
;Scratch3 register is used to save the LCRC register. LCRC is stamped with
;the initiator ID and target ID when a reconnect (initiator is selected
;by a target) occurs.
;SCRATCH0 is used to hold phase requested to be able to process a phase 
;mismatch during any data or message phase.  Usually that occur before a 
;legal disconnect from the target (save pointer and disconnect message).
; */
;
;END_DOC
;  
;/* Use to choose options in .h */
#define NCRCOMPILE

;/* Will be include by the first preprocessor pass */
#include "ncr710Script1.h"

;/* Will be include by the C compiler */
PASS(#define NCR_COMPILER_BUG)
PASS(ncr710Script1.h)
 
;/* forward declaration for C compiler. Each new procedure  must 
;   be define if it's used as a reference in the code. */

PASS(extern UINT waitSelect[];)
PASS(extern UINT reselect[];)
PASS(extern UINT checkNewCmd[];)
PASS(extern UINT startNewCmd[];)
PASS(extern UINT selWithAtn[];)
PASS(extern UINT selWithoutAtn[];)
PASS(extern UINT contTransact[];)
PASS(extern UINT endTransact[];)
PASS(extern UINT msgOut1[];) 
PASS(extern UINT msgOut3[];) 
PASS(extern UINT outputData[];)
PASS(extern UINT checkOut[];)
PASS(extern UINT inputData[];)
PASS(extern UINT msg1[];)
PASS(extern UINT msg2[];)
PASS(extern UINT msg3[];)
PASS(extern UINT selectAddr[];)
PASS(extern UINT ackMsg1[];)
PASS(extern UINT ackMsg3[];)
PASS(extern UINT checkPhData[];)
PASS(extern UINT ackAtnMsg[];)
PASS(extern UINT asortPh[];)
PASS(extern UINT endAbort[];)
PASS(extern UINT reserOutPh[];)
PASS(extern UINT reserInPh[];)
PASS(extern UINT reselSelect[];)

;/******************************************************************************
;* Entry point of the script to wait for 
;* reselected or start a new command.
;*
;*/
PROC waitSelect:
move CTEST7 | B_TIMEO to CTEST7
move PHASE_NOPHASE to SCRATCH0
wait RESELECT PASS((UINT)checkNewCmd)
jump PASS((UINT)reselect)

;/******************************************************************************
;* Entry point to get msgin and perform  
;* reconnection phase for the cpu
;*/
PROC reselect:
;/* clear target mode */
clear target
;/* Save reselected device id in SCRATCH3 */
move LCRC to SFBR
move SFBR to SCRATCH3
;/* an identify message must be the next */
move from PASS(IDENTCOUNT), when MSG_IN
;/* interrupt cpu to restore the context */
int PASS(RECONNECT_PROCESS)

PROC checkNewCmd:
;/* check if we are connected */
move SCNTL1 & B_CON to SFBR