 ttl UniFLEX Disk Formatter
 sttl CMI 5" Winchester Bootstrap
 pag
 info Bootstrap for GIMIX/Xebec Version 2.02; 10/17/83

* UniFLEX Bootstrap Loader for CMI 5" Winchester

 global uboot,DCtbl
 global RDScmdSRT,RSScmdSRT,IDCcmdSRT

* Equates
ffmap equ 17 file map offset in fdn
bhxfr equ 10 transfer address offset in header
BHDSIZ equ 24 binary file header size
*
* equates and addresses
*
CMICMD equ $F100 disk command register
CMIADR equ CMICMD+1 DMA address registers
XBCCOM equ CMICMD+4 Xebec Command Register
CMIREQ equ %00000001 Controller Request Data
CMIRDS equ $08 Read Sector
CMIRSS equ $03 Request Sense Status
CMIIDC equ $0C Initialize Drive Characteristics

* Temporary storage

 base $00E0 Page 0 data

cmiesw rmb 2 CMI Error Status Word
cmisbf rmb 4 CMI Sense Status Buffer
btdate rmb 4
direct rmb 1
mapptr rmb 2
fdnbkn rmb 3
entrys rmb 2
xfradr rmb 2

* System Configuration Info
 base $000C
cputyp rmb 2

*
old_org equ $B000 Old boot origin
new_org equ $B800 New boot origin

 base new_org+512
buffer rmb 512
map rmb 512

*  ROM addresses
pdata equ $F800
outhex equ $F802
outspc equ $F804
*

 data

* Lookup "uniflex" in directory

uboot ldx #old_org move bootstrap
 ldu #new_org
10 ldd ,x++
 std ,u++
 cmpx #old_org+512
 blo 10b
 lbra (uboot1-old_org)+new_org
*
uboot1 bsr cmiidf initialize CMI controller
 ldd #1 root directory fdn no.
 lbsr fdnblk read in fdn
 ldd 7,y find size of directory
 lbsr divby8
 lsra
 rorb
 std entrys save entry count
read1 lbsr rdblk read data block
 lbne noboot exit if error
lookup
 leax 2,u point to filespec
 leay btname,pcr point to boot file name
 ldb #14 set name length
cmpnam lda 0,x+
 cmpa 0,y+ is this boot file entry?
 bne nxtent if not, skip to next
 decb
 bne cmpnam
 ldd 0,u found it, get fdn
 bra load go load uniflex
nxtent ldx entrys
 leax -1,x decrement count
 stx entrys end of directory?
 lbeq noboot error if so
 leau 16,u point to next entry
 cmpu #buffer+512 past current block?
 bne lookup check entry if not
 bra read1 else, get another block

*
* Initialize Xebec Controller
*
cmiidf lda #1 send IDC command
 leax IDCcmd,pcr
 lbsr cmicn send command
cmiid0 lbsr cmiwt wait for READY
 bitb #$14 wait for REQ=1, I/O=0, C/D=0
 bne cmiid0
 leax DCtbl,pcr Device Characteristics table
 lda #8
cmiid1 lbsr cmiwt wait for READY
 ldb ,x+ send next byte
 stb XBCCOM
 deca done?
 bne cmiid1
 lbra cmist get status and return

* Load UniFLEX

load bsr fdnblk read in uniflex fdn
 ldx mapptr point to fdn map
 leax 13*3,x skip map
 ldd ,x++ save fdn date
 std btdate
 ldd ,x++
 std btdate+2
 lbsr rdblk read 1st block of the file
 bne noboot exit if error
 ldd bhxfr,u get transfer address
 std xfradr save it
 leau BHDSIZ,u skip binary file header
getrc1 bsr getchr get record length in x
 tfr b,a
 bsr getchr
 pshs d terminator?
 ldx ,s++ transfer count in X
 beq done start uniflex if so
 bsr getchr get load address in y
 tfr b,a
 bsr getchr
 tfr d,y
getrc2 bsr getchr get a data byte
 stb 0,y+ put in memory
 leax -1,x decrement the count
 bne getrc2 loop if not end of record
 bra getrc1 else, get next record

* Uniflex is loaded, begin execution

done ldy $5002 get boot date vector
 ldd btdate
 std ,y++
 ldd btdate+2
 std ,y++
 jmp [xfradr] jump to transfer address

* Divide contents of D by 8

divby8 lsra
 rorb
 lsra
 rorb
 lsra
 rorb
 rts

* Get single character from binary file

getchr cmpu #buffer+512 more data in buffer?
 bne getch2 skip if so
 pshs a,x,y
 bsr rdblk else, read another block
 puls a,x,y
 bne nbootx exit if error
getch2 ldb 0,u+ get character, advance ptr
 rts

* Uniflex file was not found

nbootx puls d fix stack
noboot rts return to monitor ROM

* Read fdn specified in D

fdnblk
 pshs d save fdn number
 addd #15 convert to block number
 bsr divby8
 std fdnbkn+1 save fdn block #
 clr fdnbkn
 ldy #fdnbkn
 bsr mread read a block
 puls d restore fdn number
 bne nbootx exit if error
 decb calculate buffer offset
 andb #$07
 lda #64
 mul offset=(fdn&7)*64
 addd #map
 tfr d,y fdn pointer in y
 addd #9 point to ffmap
 std mapptr save map pointer
 lda #10 get direct block count
 sta direct initialize indirect flag
 rts

* Read a block from file

rdblk
 tst direct a direct block?
 beq chgind change to indirect
 dec direct dec. direct count
 ldy mapptr get file map pointer
 ldx #buffer setup buffer address
 bsr xread read the sector
 pshs cc
 sty mapptr
 puls cc,pc

chgind ldy mapptr get file map pointer
 bsr mread read block of indirects
 bne nbootx exit if error
 stu mapptr reset file map pointer
 lda #128 set new direct count
 sta direct
 bra rdblk now read data block

* Read the specified map block

mread ldx #map address of buffer for block

* Read a single sector
*  X - Buffer Address
*  Y - Block # Pointer

xread
 leau 0,x save X pointer
 bsr setadr set up DMA address
 lda ,y+ set up block #
 sta RDSblk,pcr
 ldd ,y++
 std RDSblk+1,pcr
 lda #$21 set up for DMA/no IRQ
 leax RDScmd,pcr Read Sector Command
 bsr cmicn send command
 bra cmist read status

* convert address for dmaf

setadr lda $010B get memory map value
 tfr a,b
 lsra get upper half
 lsra
 lsra
 lsra
 sta CMIADR set up DMA address
 lda cputyp check CPU type
 bmi 10f jump for GIMIX III (positive DAT)
 comb
10 lslb get lower half
 lslb
 lslb
 lslb
 pshs b save it
 tfr x,d get address
 anda #$0F mask off upper 4 bits
 ora 0,s+ replace with map bits
 std CMIADR+1
 rts
*
* cmicn - set up CMI command and send to Xebec
*    A - DMA/IRQ select mask
*    X - Xebec Device Control Block (Command)
*
cmicn sta CMICMD set up DMA/IRQ selection
 lda #6 send 6 bytes
cmicn3 bsr cmiwt wait for READY
 ldb ,x+ get next byte
 stb XBCCOM send to controller
 deca done?
 bne cmicn3
 rts
*
* cmist - wait for operation complete & get status
*   A - Operation Status (error code)
*   X - Destroyed
*
cmist lda CMICMD wait for command completion
 bpl cmist
cmist0 bsr cmiwt get command status
 lda XBCCOM
 pshs a
 bsr cmiwt
 ldb XBCCOM
 puls a
 bita #2 error bit set?
 beq cmist9 no - exit
 leax <MAmsg,pcr
 jsr [pdata]
 lda #1 no DMA/IRQ
 leax RSScmd,pcr Request Sense Status
 bsr cmicn send command
 lda #4
cmist1 bsr cmiwt wait for READY
 pshs a save counter on stack
 lda XBCCOM get data
 jsr [outhex]
 jsr [outspc]
 puls a restore count
 deca done?
 bne cmist1
 bsr cmiwt get command status
 lda XBCCOM
 bsr cmiwt
 ldb XBCCOM
 puls d,x clean up stack - major error code in A
 anda #$7F
 cmpa #$18 allow ECC correctable errors through
cmist9 rts return
MAmsg fcc $d,'Error: ',0
*
*  Wait for Xebec to request data
*
cmiwt ldb CMICMD test READY
 bitb #1
 beq cmiwt wait until READY
 rts
*
*  Data Space for Bootstrap Loader
*
RDScmd fcb CMIRDS Read Sector Command
RDSblk rzb 3 Block #
 fcb 1 1 Sector
RDScmdSRT fcb $04 -- set up by format
RSScmd fcb CMIRSS Request Sense Status Command
 fcb 0,0,0,0
RSScmdSRT fcb $04 -- set up by format
IDCcmd fcb CMIIDC Initialize Drive Characteristics
 fcb 0,0,0,0
IDCcmdSRT fcb $04 -- set up by format
DCtbl fdb 306 Cylinders
 fcb 6 Heads
 fdb 306 Begin reduced write
 fdb 306 Begin write precompensation
 fcb 11 Max ECC burst


* filename for booting

btname fcc 'uniflex'
 fcb 0,0,0,0,0,0,0

* filler bytes

 if (*-uboot)>512
 err 'Bootstrap overflow'
 else
 rzb 512-(*-uboot)
 endif
 end
