URL https://opencores.org/ocsvn/System09/System09/trunk

Subversion Repositories System09

[/] [System09/] [trunk/] [src/] [boot/] [bootcf8.asm] - Blame information for rev 131

Go to most recent revision | Details | Compare with Previous | View Log


*******************************************************
*
* Bootstrap FLEX Loader
*
* SBUG1.8 loads the bootstap loader at $C000
* however the Flex adaption manual has the
* bootstrap loader residing at $C100
*
******************************************************
*
* Equates
*
STACK   EQU $C0FF
SCTBUF  EQU $C300
*
* Start of Utility
*
        ORG $C000
BOOT    BRA LOAD0
        FCB 0,0,0
TRK     FCB 0        File start track
SCT     FCB 0        File start sector
DNS     FCB 0        Density Flag (not used)
TADR    FDB $C000    Transfer address
LADR    FDB 0        Load Address
DRVNUM  FCB 0        Drive number 0
*
LOAD0   LDS  #STACK   Set up stack
        LDD  TRK      Set up start track and sector
        STD  SCTBUF
        LDY  #SCTBUF+256
*
* Perform actual file load
*
LOAD1   BSR GETCH    Get acharcater
        CMPA #$02    Data record hearder ?
        BEQ  LOAD2   Skip, is so
        CMPA #$16    Xfr address hearder ?
        BNE LOAD1    Loop if neither
*
* Get transfer address
*
        BSR  GETCH
        STA  TADR
        BSR  GETCH
        STA  TADR+1
        BRA  LOAD1
*
* Load data record
*
LOAD2  BSR  GETCH  Get load address
       STA  LADR
       BSR  GETCH
       STA  LADR+1
       BSR  GETCH  Get Bytes count
       TFR  A,B
       TSTB
       BEQ  LOAD1 Loop if count = 0
       LDX  LADR  Get load address
LOAD3  PSHS B,X
       BSR  GETCH  Get data character
       PULS B,X
       STA  ,X+    Store at load address
       DECB
       BNE  LOAD3  Loop until count = 0
       BRA  LOAD1
*
* Get Character routine
* Reads a sector if needed
*
GETCH  CMPY #SCTBUF+256 out of data ?
       BNE  GETCH4      Go read Character if not
GETCH2 LDX  #SCTBUF     Point to buffer
       LDD  0,X         Get forward Link
       BEQ  GO          if zero, file is loaded
       BSR  READ        Read next sector
       BNE  BOOT        start over if error
       LDY  #SCTBUF+4   Point past link
GETCH4 LDA  ,Y+         Else, get a character
       RTS
*
* File is loaded, Jump to it
*
GO     JMP  [TADR]      Jump to transfer address
 
*
** FLEX 9 COMPACT FLASH DISK DRIVERS
*
* FOR SYS09BUG 1.2 ON THE BURCHED B5-X300
* WITH I/O MAPPED AT $XE000
* AND ROM MAPPED AT $XF000
* THE BURCHED B5-X300 HAS 256KBYTES OF SRAM
* THE FIRST 64K IS USED BY FLEX,
* THE SECOND 192K MAY BE USED AS A RAM DISK
*
*
IMASK  EQU $10     IRQ MASK CC
FMASK  EQU $40     FIRQ MASK CC
DATREG EQU $FFF0   DAT REGISTERS
*
CF_BASE    EQU $E040
CF_DATA    EQU CF_BASE+0
CF_ERROR   EQU CF_BASE+1 ; read error
CF_FEATURE EQU CF_BASE+1 ; write feature
CF_SECCNT  EQU CF_BASE+2
CF_SECNUM  EQU CF_BASE+3
CF_CYLLO   EQU CF_BASE+4
CF_CYLHI   EQU CF_BASE+5
CF_HEAD    EQU CF_BASE+6
CF_STATUS  EQU CF_BASE+7 ; read status
CF_COMAND  EQU CF_BASE+7 ; write command
*
* Command Equates
*
CMDREAD    EQU $20 ; Read Single sector
CMDWRITE   EQU $30 ; Write Single sector
CMDFEATURE EQU $EF
FEAT8BIT   EQU $01 ; enable 8 bit transfers
HEADLBA    EQU $E0
*
* Status bit equates
*
BSY        EQU $80
DRDY       EQU $40
DRQ        EQU $08
ERR        EQU $01
*
* RESTORE DISK DRIVER (SEEK TRACK 00)
*
RESTR1 CLR  DRVNUM
       CLRA           ; Track 0
       LDB  #$01     ; Sector 1
*
* Seek track and sector
* A holds track number (0 - ??)
* B holds sector number (1 - ??)
* Sector numbers starts from 1
* subtract 1 to start from sector 0 on CF
*
SEEKTS DECB
       STB  CF_SECNUM
       STA  CF_CYLLO
       LDB  DRVNUM
       STB  CF_CYLHI
       LDB  #$01
       STB  CF_SECCNT
       CLRB
WARMD1 RTS
*
* READ SECTORS FROM CF
*
*
READ   BSR  SEEKTS
       LDA  #CMDREAD ; IDE READ MULTIPLE
       STA  CF_COMAND
       BSR  WAITRDY
*
* READ LOOP
*
       CLRB
RDLP1  BSR  WAITDRQ
       LDA  CF_DATA
       STA  ,X+
       DECB
       BNE  RDLP1
*
       CLRB
RDLP2  BSR  WAITDRQ
       LDA  CF_DATA
       DECB
       BNE  RDLP2
*
       BSR  WAITRDY
       CLRB
       RTS
*
* WAIT UNTIL READY
*
WAITRDY LDA  CF_STATUS
        BITA #BSY
        BNE  WAITRDY
        LDA  CF_STATUS
        BITA #DRDY
        BEQ  WAITRDY
        RTS
*
* WAIT FOR DATA REQUEST
*
WAITDRQ LDA  CF_STATUS
        BITA #DRQ
        BEQ  WAITDRQ
        RTS
*
        END

Line No.	Rev	Author	Line
1	59	davidgb	`*******************************************************`
2			`*`
3			`* Bootstrap FLEX Loader`
4			`*`
5			`* SBUG1.8 loads the bootstap loader at $C000`
6			`* however the Flex adaption manual has the`
7			`* bootstrap loader residing at $C100`
8			`*`
9			`******************************************************`
10			`*`
11			`* Equates`
12			`*`
13			`STACK EQU $C0FF`
14			`SCTBUF EQU $C300`
15			`*`
16			`* Start of Utility`
17			`*`
18			`ORG $C000`
19			`BOOT BRA LOAD0`
20			`FCB 0,0,0`
21			`TRK FCB 0 File start track`
22			`SCT FCB 0 File start sector`
23			`DNS FCB 0 Density Flag (not used)`
24			`TADR FDB $C000 Transfer address`
25			`LADR FDB 0 Load Address`
26			`DRVNUM FCB 0 Drive number 0`
27			`*`
28			`LOAD0 LDS #STACK Set up stack`
29			`LDD TRK Set up start track and sector`
30			`STD SCTBUF`
31			`LDY #SCTBUF+256`
32			`*`
33			`* Perform actual file load`
34			`*`
35			`LOAD1 BSR GETCH Get acharcater`
36			`CMPA #$02 Data record hearder ?`
37			`BEQ LOAD2 Skip, is so`
38			`CMPA #$16 Xfr address hearder ?`
39			`BNE LOAD1 Loop if neither`
40			`*`
41			`* Get transfer address`
42			`*`
43			`BSR GETCH`
44			`STA TADR`
45			`BSR GETCH`
46			`STA TADR+1`
47			`BRA LOAD1`
48			`*`
49			`* Load data record`
50			`*`
51			`LOAD2 BSR GETCH Get load address`
52			`STA LADR`
53			`BSR GETCH`
54			`STA LADR+1`
55			`BSR GETCH Get Bytes count`
56			`TFR A,B`
57			`TSTB`
58			`BEQ LOAD1 Loop if count = 0`
59			`LDX LADR Get load address`
60			`LOAD3 PSHS B,X`
61			`BSR GETCH Get data character`
62			`PULS B,X`
63			`STA ,X+ Store at load address`
64			`DECB`
65			`BNE LOAD3 Loop until count = 0`
66			`BRA LOAD1`
67			`*`
68			`* Get Character routine`
69			`* Reads a sector if needed`
70			`*`
71			`GETCH CMPY #SCTBUF+256 out of data ?`
72			`BNE GETCH4 Go read Character if not`
73			`GETCH2 LDX #SCTBUF Point to buffer`
74			`LDD 0,X Get forward Link`
75			`BEQ GO if zero, file is loaded`
76			`BSR READ Read next sector`
77			`BNE BOOT start over if error`
78			`LDY #SCTBUF+4 Point past link`
79			`GETCH4 LDA ,Y+ Else, get a character`
80			`RTS`
81			`*`
82			`* File is loaded, Jump to it`
83			`*`
84			`GO JMP [TADR] Jump to transfer address`
85
86			`*`
87			`** FLEX 9 COMPACT FLASH DISK DRIVERS`
88			`*`
89			`* FOR SYS09BUG 1.2 ON THE BURCHED B5-X300`
90			`* WITH I/O MAPPED AT $XE000`
91			`* AND ROM MAPPED AT $XF000`
92			`* THE BURCHED B5-X300 HAS 256KBYTES OF SRAM`
93			`* THE FIRST 64K IS USED BY FLEX,`
94			`* THE SECOND 192K MAY BE USED AS A RAM DISK`
95			`*`
96			`*`
97			`IMASK EQU $10 IRQ MASK CC`
98			`FMASK EQU $40 FIRQ MASK CC`
99			`DATREG EQU $FFF0 DAT REGISTERS`
100			`*`
101			`CF_BASE EQU $E040`
102			`CF_DATA EQU CF_BASE+0`
103			`CF_ERROR EQU CF_BASE+1 ; read error`
104			`CF_FEATURE EQU CF_BASE+1 ; write feature`
105			`CF_SECCNT EQU CF_BASE+2`
106			`CF_SECNUM EQU CF_BASE+3`
107			`CF_CYLLO EQU CF_BASE+4`
108			`CF_CYLHI EQU CF_BASE+5`
109			`CF_HEAD EQU CF_BASE+6`
110			`CF_STATUS EQU CF_BASE+7 ; read status`
111			`CF_COMAND EQU CF_BASE+7 ; write command`
112			`*`
113			`* Command Equates`
114			`*`
115			`CMDREAD EQU $20 ; Read Single sector`
116			`CMDWRITE EQU $30 ; Write Single sector`
117			`CMDFEATURE EQU $EF`
118			`FEAT8BIT EQU $01 ; enable 8 bit transfers`
119			`HEADLBA EQU $E0`
120			`*`
121			`* Status bit equates`
122			`*`
123			`BSY EQU $80`
124			`DRDY EQU $40`
125			`DRQ EQU $08`
126			`ERR EQU $01`
127			`*`
128			`* RESTORE DISK DRIVER (SEEK TRACK 00)`
129			`*`
130			`RESTR1 CLR DRVNUM`
131			`CLRA ; Track 0`
132			`LDB #$01 ; Sector 1`
133			`*`
134			`* Seek track and sector`
135			`* A holds track number (0 - ??)`
136			`* B holds sector number (1 - ??)`
137			`* Sector numbers starts from 1`
138			`* subtract 1 to start from sector 0 on CF`
139			`*`
140			`SEEKTS DECB`
141			`STB CF_SECNUM`
142			`STA CF_CYLLO`
143			`LDB DRVNUM`
144			`STB CF_CYLHI`
145			`LDB #$01`
146			`STB CF_SECCNT`
147			`CLRB`
148			`WARMD1 RTS`
149			`*`
150			`* READ SECTORS FROM CF`
151			`*`
152			`*`
153			`READ BSR SEEKTS`
154			`LDA #CMDREAD ; IDE READ MULTIPLE`
155			`STA CF_COMAND`
156			`BSR WAITRDY`
157			`*`
158			`* READ LOOP`
159			`*`
160			`CLRB`
161			`RDLP1 BSR WAITDRQ`
162			`LDA CF_DATA`
163			`STA ,X+`
164			`DECB`
165			`BNE RDLP1`
166			`*`
167			`CLRB`
168			`RDLP2 BSR WAITDRQ`
169			`LDA CF_DATA`
170			`DECB`
171			`BNE RDLP2`
172			`*`
173			`BSR WAITRDY`
174			`CLRB`
175			`RTS`
176			`*`
177			`* WAIT UNTIL READY`
178			`*`
179			`WAITRDY LDA CF_STATUS`
180			`BITA #BSY`
181			`BNE WAITRDY`
182			`LDA CF_STATUS`
183			`BITA #DRDY`
184			`BEQ WAITRDY`
185			`RTS`
186			`*`
187			`* WAIT FOR DATA REQUEST`
188			`*`
189			`WAITDRQ LDA CF_STATUS`
190			`BITA #DRQ`
191			`BEQ WAITDRQ`
192			`RTS`
193			`*`
194			`END`

Browse

Tools

Subversion Repositories System09

[/] [System09/] [trunk/] [src/] [boot/] [bootcf8.asm] - Blame information for rev 131