; general.ss  Revision 2.0 1/1/93  GJ      

;       Single-threaded general purpose script

;       Definition area INITIATOR ROLE (really starting roll)

;       Offset for counts and addresses in the table
Absolute sendmsg=0x00
Absolute rcvmsg=0x08
Absolute cmd_adr=0x10
Absolute device=0x18
Absolute status_adr=0x20
Absolute ext_buf=0x28
Absolute sync_in=0x30
Absolute data_adr=0x38
   
;       The script has finished initilizing the c8xx.
Absolute done_init = 0x01

ABSOLUTE ok = 0x00
ABSOLUTE err1 = 0x0ff01
ABSOLUTE err2 = 0x0ff02
ABSOLUTE err3 = 0x0ff03
ABSOLUTE err4 = 0x0ff04
ABSOLUTE err5 = 0x0ff05
ABSOLUTE err6 = 0x0ff06
ABSOLUTE err7 = 0x0ff07
ABSOLUTE err8 = 0x0ff08
ABSOLUTE err9 = 0x0ff09

;       The addresses of chip registers that we need to access
ABSOLUTE scratch_adr = 0xdfe34
ABSOLUTE dsa_adr = 0xdfe10

EXTERN dsa_storage, out_offset, in_offset

;       SCSI I/O entry point.  This address must be loaded into the 
;       53C8xx before initiating a SCSI I/O.
ENTRY init_siop
ENTRY start_up
ENTRY switch
ENTRY datain
ENTRY dataout

init_siop:
	INT done_init

start_up:

SELECT ATN FROM device, REL(resel)

;       Every phase comes back to here.
switch:
	JUMP REL(msgin), WHEN MSG_IN
	JUMP REL(msgout), IF MSG_OUT
	JUMP REL(command_phase), IF CMD
	JUMP REL(dataout), IF DATA_OUT
	JUMP REL(datain), IF DATA_IN
	JUMP REL(end), IF STATUS

	INT err1

msgin:
	MOVE FROM rcvmsg, WHEN MSG_IN
	JUMP REL(ext_msg), IF 0x01
	JUMP REL(disc), IF 0x04
	CLEAR ACK
	JUMP REL(switch), IF 0x02       ; ignore save data pointers
	JUMP REL(switch), IF 0x07       ; ignore message reject :)
	JUMP REL(switch), IF 0x03       ; ignore restore data pointers
	INT err2

ext_msg:
	CLEAR ACK
	MOVE FROM ext_buf, WHEN MSG_IN
	JUMP REL(sync_msg), IF 0x03
	
	INT err3

sync_msg:
	CLEAR ACK        
	MOVE FROM sync_in, WHEN MSG_IN
	CLEAR ACK
	JUMP REL(switch)

disc:
	MOVE SCNTL2 & 0x7f to SCNTL2            ;expect disconnect
	CLEAR ACK
	WAIT DISCONNECT
	
	WAIT RESELECT REL(select_adr)
	
	INT err4, WHEN NOT MSG_IN
	MOVE FROM rcvmsg, WHEN MSG_IN
	CLEAR ACK
	INT err9
	JUMP REL(switch)                 

msgout:
	MOVE FROM sendmsg, WHEN MSG_OUT
	JUMP REL(switch)

command_phase:
	MOVE FROM cmd_adr, WHEN CMD
	JUMP REL(switch)

;       After every data transfer add 8 to data_adr.  This allows 
;       A scatter/gather operation when the list of addresses to
;       read or write is appended to the end of the buffer_table.

dataout:
	MOVE FROM data_adr, WHEN DATA_OUT
    MOVE DMODE & 0xDF TO DMODE  ;Clear SIOM
    MOVE DMODE | 0x10 TO DMODE  ;Set DIOM
    MOVE MEMORY 4, out_offset, scratch_adr
    MOVE DMODE & 0xCF TO DMODE  ;Clear SIOM and DIOM
	CALL REL(addscratch)
    MOVE DMODE | 0x20 TO DMODE  ;Set SIOM
    MOVE DMODE & 0xEF TO DMODE  ;Clear DIOM
    MOVE MEMORY 4, scratch_adr, out_offset
    MOVE DMODE & 0xCF TO DMODE  ;Clear SIOM and DIOM
    JUMP REL(switch)

datain:
	MOVE FROM data_adr, WHEN DATA_IN
    MOVE DMODE & 0xDF TO DMODE  ;Clear SIOM
    MOVE DMODE | 0x10 TO DMODE  ;Set DIOM
    MOVE MEMORY 4, in_offset, scratch_adr
    MOVE DMODE & 0xCF TO DMODE  ;Clear SIOM and DIOM
	CALL REL(addscratch)
    MOVE DMODE | 0x20 TO DMODE  ;Set SIOM
    MOVE DMODE & 0xEF TO DMODE  ;Clear DIOM
    MOVE MEMORY 4, scratch_adr, in_offset
    MOVE DMODE & 0xCF TO DMODE  ;Clear SIOM and DIOM
    JUMP REL(switch)

addscratch:
	MOVE SCRATCHA0 + 8 to SCRATCHA0
	MOVE SCRATCHA0 to SFBR
	JUMP REL(ck_carry), IF 0x00
	RETURN

ck_carry:
	MOVE SCRATCHA1 + 1 to SCRATCHA1
	RETURN

end:
	MOVE FROM status_adr, WHEN STATUS
	INT err5, WHEN NOT MSG_IN               
	MOVE FROM rcvmsg, WHEN MSG_IN
	MOVE SCNTL2 & 0x7f to SCNTL2            ;expect disconnect
	CLEAR ACK
	WAIT DISCONNECT
	INT ok

resel:
	INT err6

select_adr:
	INT err7