| 
 | 1 | +; Driver protection  | 
 | 2 | +;  | 
 | 3 | +; Make generic by Norman Davie  | 
 | 4 | +; Adapted from code by Thomas Cherryhomes  | 
 | 5 | +;  | 
 | 6 | + | 
 | 7 | +; Pointers used by relocator.  | 
 | 8 | + | 
 | 9 | +RELOCATE_TABLE		=	$A2  | 
 | 10 | +RELOCATE_TABLE_LO	=	$A2  | 
 | 11 | +RELOCATE_TABLE_HI	= 	$A3  | 
 | 12 | + | 
 | 13 | +SRC_ADDR		=	$A4  | 
 | 14 | +SRC_ADDR_LO		=	$A4  | 
 | 15 | +SRC_ADDR_HI		=	$A5  | 
 | 16 | + | 
 | 17 | +FROM:			=	$A6  | 
 | 18 | +FROM_LO:		=	$A6  | 
 | 19 | +FROM_HI:		=	$A7  | 
 | 20 | + | 
 | 21 | +TO:			=	$A8  | 
 | 22 | +TO_LO			=	$A8  | 
 | 23 | +TO_HI			=	$A9  | 
 | 24 | + | 
 | 25 | +MOD_ADDR		=	$AA  | 
 | 26 | +MOD_ADDR_LO		=	$AA  | 
 | 27 | +MOD_ADDR_HI		=	$AB  | 
 | 28 | + | 
 | 29 | +       ; INTERRUPT VECTORS  | 
 | 30 | +       ; AND OTHER PAGE 2 VARS  | 
 | 31 | + | 
 | 32 | +VPRCED  		=     	$0202   ; PROCEED VCTR  | 
 | 33 | +MEMLO   		=     	$02E7   ; MEM LO  | 
 | 34 | + | 
 | 35 | +SETVBV			= 	$E45C  | 
 | 36 | +XITVBV			=	$E462  | 
 | 37 | + | 
 | 38 | +       ; HARDWARE REGISTERS  | 
 | 39 | + | 
 | 40 | +PACTL   		= 	$D302	; PIA CTRL A  | 
 | 41 | + | 
 | 42 | +;DEBUG			= 	$AD  | 
 | 43 | + | 
 | 44 | +; A = Low byte of relocation table  | 
 | 45 | +; Y = high byte of relocation table  | 
 | 46 | + | 
 | 47 | + | 
 | 48 | +;;; RESET HANDLER ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  | 
 | 49 | +;  | 
 | 50 | +;RESET:      | 
 | 51 | +;    JSR    $FFFF        ; Modified for original DOSINI  | 
 | 52 | +;    LDA    #$FF        ; Driver end LO  | 
 | 53 | +;    STA     MEMLO  | 
 | 54 | +;    LDA    #$FF        ; Driver end HI  | 
 | 55 | +;    STA    MEMLO+1  | 
 | 56 | +;    JSR     INIT            ; call any inits.  | 
 | 57 | +;    JSR    CLALL  | 
 | 58 | +;    RTS      | 
 | 59 | +;;; END RESET HANDLER ;;;;;;;;;;;;;;;;;;;;;;;;;;;;  | 
 | 60 | + | 
 | 61 | +RELOCATE_TO_MEMLO:  | 
 | 62 | + | 
 | 63 | +	STA RELOCATE_TABLE_LO  | 
 | 64 | +	STY RELOCATE_TABLE_HI  | 
 | 65 | + | 
 | 66 | + | 
 | 67 | +.ifdef DEBUG  | 
 | 68 | +	LDA #$00  | 
 | 69 | +	STA DEBUG  | 
 | 70 | +.endif  | 
 | 71 | +	LDA MEMLO  | 
 | 72 | +	STA TO_LO  | 
 | 73 | +	LDA MEMLO+1  | 
 | 74 | +	STA TO_HI  | 
 | 75 | + | 
 | 76 | +; First entry in relocation table  | 
 | 77 | +; is the SOURCE ADDRESS of the block  | 
 | 78 | + | 
 | 79 | +	LDY #$00  | 
 | 80 | +	  | 
 | 81 | +	LDA (RELOCATE_TABLE),Y  | 
 | 82 | +	STA SRC_ADDR_LO  | 
 | 83 | +	STA FROM_LO  | 
 | 84 | +	INY  | 
 | 85 | +	LDA (RELOCATE_TABLE),Y  | 
 | 86 | +	STA SRC_ADDR_HI  | 
 | 87 | +	STA FROM_HI  | 
 | 88 | + | 
 | 89 | +; Second entry in relocation table  | 
 | 90 | +; is the size of the block  | 
 | 91 | + | 
 | 92 | +	INY  | 
 | 93 | +	LDA (RELOCATE_TABLE),Y  | 
 | 94 | +	STA RELOCATE_SIZE_LO  | 
 | 95 | +	STA COPY_SIZE_LO  | 
 | 96 | +	INY  | 
 | 97 | +	LDA (RELOCATE_TABLE),Y  | 
 | 98 | +	STA RELOCATE_SIZE_HI  | 
 | 99 | +	STA COPY_SIZE_HI  | 
 | 100 | +	  | 
 | 101 | +.ifdef DEBUG  | 
 | 102 | +; It may appear this is unnecessary since we're  | 
 | 103 | +; dong it twice, but actually we need the data  | 
 | 104 | +; present in order to use these routines  | 
 | 105 | +; while we're moving  | 
 | 106 | + | 
 | 107 | +	LDA MEMLO  | 
 | 108 | +	STA TO_LO  | 
 | 109 | +	LDA MEMLO+1  | 
 | 110 | +	STA TO_HI  | 
 | 111 | + | 
 | 112 | +	TYA  | 
 | 113 | +	PHA	  | 
 | 114 | +	JSR MOVE_TO_TARGET  | 
 | 115 | +	PLA  | 
 | 116 | +	TAY  | 
 | 117 | +	  | 
 | 118 | +	LDA MEMLO  | 
 | 119 | +	STA TO_LO  | 
 | 120 | +	LDA MEMLO+1  | 
 | 121 | +	STA TO_HI  | 
 | 122 | +.endif  | 
 | 123 | +	  | 
 | 124 | +		  | 
 | 125 | +; Third entry is the number of relocation entries  | 
 | 126 | + | 
 | 127 | +	INY  | 
 | 128 | +	LDA (RELOCATE_TABLE),Y  | 
 | 129 | +	TAX  | 
 | 130 | +		  | 
 | 131 | +; Figure out how much we need to modify  | 
 | 132 | +; the addresses by	  | 
 | 133 | + | 
 | 134 | +	LDA SRC_ADDR_LO  | 
 | 135 | +	SEC  | 
 | 136 | +	SBC TO_LO  | 
 | 137 | +	STA DIFF_LO  | 
 | 138 | +	  | 
 | 139 | +	LDA SRC_ADDR_HI  | 
 | 140 | +	SBC TO_HI  | 
 | 141 | +	STA DIFF_HI  | 
 | 142 | +	  | 
 | 143 | +; For easier calculations of the more than  | 
 | 144 | +; 128 entries, we're going to reset the Y  | 
 | 145 | +; to zero and work from the start of the table entries.  | 
 | 146 | +; That way we just need to update the high  | 
 | 147 | +; order byte by one when we go back to zero  | 
 | 148 | + | 
 | 149 | +	INY  | 
 | 150 | +	STY START_OF_TABLE  | 
 | 151 | + | 
 | 152 | +	LDA RELOCATE_TABLE_LO  | 
 | 153 | +	CLC  | 
 | 154 | +	ADC START_OF_TABLE  | 
 | 155 | +	STA RELOCATE_TABLE_LO  | 
 | 156 | +	  | 
 | 157 | +	LDA RELOCATE_TABLE_HI  | 
 | 158 | +	ADC #$00  | 
 | 159 | +	STA RELOCATE_TABLE_HI  | 
 | 160 | +	  | 
 | 161 | +	LDY #$00  | 
 | 162 | + | 
 | 163 | + | 
 | 164 | +MODIFY_TABLE:  | 
 | 165 | + | 
 | 166 | +; add one byte to the address   | 
 | 167 | +; (we were currently pointing at the instruction)  | 
 | 168 | + | 
 | 169 | +	CLC			; add one to the relocation table address  | 
 | 170 | +	LDA (RELOCATE_TABLE),Y  | 
 | 171 | +	ADC #$01  | 
 | 172 | +	STA (RELOCATE_TABLE),Y  | 
 | 173 | + | 
 | 174 | +	INY  | 
 | 175 | +	LDA (RELOCATE_TABLE),Y  | 
 | 176 | +	ADC #$00  | 
 | 177 | +	STA (RELOCATE_TABLE),Y  | 
 | 178 | + | 
 | 179 | +	DEY			; back to the original table address  | 
 | 180 | +	  | 
 | 181 | +; now the table is pointing at the address  | 
 | 182 | +	  | 
 | 183 | +MODIFY_CODE:	  | 
 | 184 | +	  | 
 | 185 | +; we've updated the table entry to point at the address   | 
 | 186 | +; we are to modify, calculate the new destination address	  | 
 | 187 | + | 
 | 188 | + | 
 | 189 | +; read the address we're to modify  | 
 | 190 | + | 
 | 191 | +	LDA (RELOCATE_TABLE),Y		; The lo address in the table  | 
 | 192 | +	STA MOD_ADDR_LO  | 
 | 193 | + | 
 | 194 | +	INY  | 
 | 195 | +	LDA (RELOCATE_TABLE),Y		; the hi address in the table  | 
 | 196 | +	STA MOD_ADDR_HI  | 
 | 197 | + | 
 | 198 | +; Need the Y for later; save it	  | 
 | 199 | +	TYA  | 
 | 200 | +	PHA  | 
 | 201 | +	  | 
 | 202 | +.ifdef DEBUG	  | 
 | 203 | +		LDA DEBUG  | 
 | 204 | +		BEQ DEBUG_SKIP1  | 
 | 205 | +		  | 
 | 206 | +		TXA  | 
 | 207 | +		PHA  | 
 | 208 | +		TYA  | 
 | 209 | +		PHA  | 
 | 210 | +		JSR PRINT_HEX_NO_EOL  | 
 | 211 | +		LDA #<DEBUG_ARROW  | 
 | 212 | +		LDY #>DEBUG_ARROW  | 
 | 213 | +		JSR PRINT_STRING_NO_EOL  | 
 | 214 | + | 
 | 215 | +		PLA  | 
 | 216 | +		TAY  | 
 | 217 | +		  | 
 | 218 | +		LDA (RELOCATE_TABLE),Y		; the hi address in the table  | 
 | 219 | +		JSR PRINT_HEX_NO_EOL  | 
 | 220 | +		DEY   | 
 | 221 | +		LDA (RELOCATE_TABLE),Y  | 
 | 222 | +		JSR PRINT_HEX_NO_EOL  | 
 | 223 | + | 
 | 224 | +		TYA  | 
 | 225 | +		PHA		  | 
 | 226 | +		LDA #<DEBUG_ARROW  | 
 | 227 | +		LDY #>DEBUG_ARROW  | 
 | 228 | +		JSR PRINT_STRING_NO_EOL  | 
 | 229 | +		PLA  | 
 | 230 | +		TAY  | 
 | 231 | +		  | 
 | 232 | +		PLA  | 
 | 233 | +		TAX  | 
 | 234 | +DEBUG_SKIP1  | 
 | 235 | +.endif  | 
 | 236 | +		  | 
 | 237 | +; load the address and subtract the difference  | 
 | 238 | +; save the new address back  | 
 | 239 | +	  | 
 | 240 | +	LDY #$00	  | 
 | 241 | +	LDA (MOD_ADDR),Y;   | 
 | 242 | +	SEC  | 
 | 243 | +	SBC DIFF_LO  | 
 | 244 | +	STA (MOD_ADDR),Y  | 
 | 245 | +		  | 
 | 246 | +	INY  | 
 | 247 | +	LDA (MOD_ADDR),Y  | 
 | 248 | +	SBC DIFF_HI  | 
 | 249 | +	STA (MOD_ADDR),Y  | 
 | 250 | + | 
 | 251 | +.ifdef DEBUG  | 
 | 252 | +		LDA DEBUG  | 
 | 253 | +		BEQ DEBUG_SKIP2  | 
 | 254 | +		LDA (MOD_ADDR),Y  | 
 | 255 | +		JSR PRINT_HEX_NO_EOL  | 
 | 256 | +		DEY   | 
 | 257 | +		LDA (MOD_ADDR),Y  | 
 | 258 | +		JSR PRINT_HEX  | 
 | 259 | +		INY  | 
 | 260 | +DEBUG_SKIP2		  | 
 | 261 | + | 
 | 262 | +;		JSR WAIT_FOR_RETURN  | 
 | 263 | +.endif  | 
 | 264 | + | 
 | 265 | +; get our y back  | 
 | 266 | +	PLA  | 
 | 267 | +	TAY  | 
 | 268 | + | 
 | 269 | +.ifdef DEBUG  | 
 | 270 | +	CPY #$B1  | 
 | 271 | +	BNE SKIP3  | 
 | 272 | +	LDA #$01  | 
 | 273 | +	STA DEBUG  | 
 | 274 | +SKIP3:  | 
 | 275 | +.endif  | 
 | 276 | +	DEX  | 
 | 277 | +	BEQ TABLE_EXHAUSTED  | 
 | 278 | + | 
 | 279 | +	INY	; next entry  | 
 | 280 | +	BNE MODIFY_TABLE		  | 
 | 281 | +;	We've wrapped back to zero  | 
 | 282 | +	LDY #$00  | 
 | 283 | +	INC RELOCATE_TABLE_HI	  | 
 | 284 | +	CLC  | 
 | 285 | +	BCC MODIFY_TABLE  | 
 | 286 | +		  | 
 | 287 | +TABLE_EXHAUSTED:  | 
 | 288 | + | 
 | 289 | +	LDA MEMLO  | 
 | 290 | +	STA TO_LO  | 
 | 291 | +	LDA MEMLO+1  | 
 | 292 | +	STA TO_HI  | 
 | 293 | +	  | 
 | 294 | +	JSR MOVE_TO_TARGET  | 
 | 295 | +	JSR ADJUST_MEMLO  | 
 | 296 | +	RTS  | 
 | 297 | +	  | 
 | 298 | +MOVE_TO_TARGET:	  | 
 | 299 | + | 
 | 300 | +	LDY #0  | 
 | 301 | +	LDX COPY_SIZE_HI  | 
 | 302 | +	BEQ MD2  | 
 | 303 | +MD1	LDA (FROM),Y ; move a page at a time  | 
 | 304 | +	STA (TO),Y  | 
 | 305 | +	INY  | 
 | 306 | +	BNE MD1  | 
 | 307 | +	INC FROM+1  | 
 | 308 | +	INC TO+1  | 
 | 309 | +	DEX  | 
 | 310 | +	BNE MD1  | 
 | 311 | +MD2	LDX COPY_SIZE_LO  | 
 | 312 | +	BEQ MOVE_COMPLETED  | 
 | 313 | +MD3	LDA (FROM),Y ; move the remaining bytes  | 
 | 314 | +	STA (TO),Y  | 
 | 315 | +	INY  | 
 | 316 | +	DEX  | 
 | 317 | +	BNE MD3  | 
 | 318 | + | 
 | 319 | +MOVE_COMPLETED  | 
 | 320 | +	RTS  | 
 | 321 | +	  | 
 | 322 | +ADJUST_MEMLO:  | 
 | 323 | + | 
 | 324 | +; 	ADJUST MEMLO TO PROTECT US  | 
 | 325 | +	  | 
 | 326 | +	SEI  | 
 | 327 | +	CLC  | 
 | 328 | +	LDA MEMLO  | 
 | 329 | +	ADC RELOCATE_SIZE_LO  | 
 | 330 | +	STA MEMLO  | 
 | 331 | +	LDA MEMLO+1  | 
 | 332 | +	ADC RELOCATE_SIZE_HI  | 
 | 333 | +	STA MEMLO+1  | 
 | 334 | +	CLI  | 
 | 335 | +	  | 
 | 336 | +	RTS  | 
 | 337 | +	  | 
 | 338 | +	  | 
 | 339 | +; Each entry is points to the instruction   | 
 | 340 | +; (not the address) we need to relocate  | 
 | 341 | + | 
 | 342 | +	  | 
 | 343 | +RELOCATE_SIZE:  | 
 | 344 | +RELOCATE_SIZE_LO:	.BYTE $00  | 
 | 345 | +RELOCATE_SIZE_HI:	.BYTE $00  | 
 | 346 | + | 
 | 347 | +COPY_SIZE:  | 
 | 348 | +COPY_SIZE_LO:		.BYTE $00  | 
 | 349 | +COPY_SIZE_HI:		.BYTE $00  | 
 | 350 | + | 
 | 351 | +DIFF:  | 
 | 352 | +DIFF_LO:		.BYTE $00  | 
 | 353 | +DIFF_HI:		.BYTE $00  | 
 | 354 | + | 
 | 355 | +START_OF_TABLE		.BYTE $00  | 
 | 356 | +FIRST_TIME		.BYTE $01  | 
 | 357 | + | 
 | 358 | + | 
 | 359 | + | 
 | 360 | +DEBUG1:  | 
 | 361 | +DEBUG1_LO:		.BYTE $00  | 
 | 362 | +DEBUG1_HI		.BYTE $00  | 
 | 363 | + | 
 | 364 | +DEBUG2:  | 
 | 365 | +DEBUG2_LO:		.BYTE $00  | 
 | 366 | +DEBUG2_HI		.BYTE $00  | 
 | 367 | + | 
 | 368 | +DEBUG3:  | 
 | 369 | +DEBUG3_LO:		.BYTE $00  | 
 | 370 | +DEBUG3_HI:		.BYTE $00  | 
 | 371 | + | 
 | 372 | +Y:			.BYTE $00  | 
 | 373 | + | 
 | 374 | +DEBUG_ARROW:		.BYTE ' -> ',0		  | 
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