I think this is related to this this question, but the consts in the example code don't exist in mine, so maybe it's a different level of compression, but I am unsure.
Can anyone provide me the right direction to take to get this code working?
My sample compressed data is 6F600020 D0F77B6A 7972F760 E62BE917 4E6FE968 9E0AC682 02E7EEE5 3D1F235E 8C63D0E0
The routine I found doing what I suspect is the decompression
It seems to go byte by byte in getting stuff from ROM, then popping it back to VRAM to be displayed, I've looked through the source of JCALG but I can't seem to make entire sense of what is going on infront of me.
030001F8 addcs r9,r9,2h ;1 235
030001FC bcs Lxx_3000224h ;3 238
03000200 ldr r8,=Lxx_27Fh ;3 241
03000204 cmp r12,r8 ;1 242
03000208 addcs r9,r9,1h ;1 243
0300020C bcs Lxx_3000224h ;3 246
03000210 cmp r12,7Fh ;1 247
03000214 bhi Lxx_3000224h ;3 250
03000218 add r9,r9,4h ;1 251
0300021C cmp r12,1h ;1 252
03000220 beq Lxx_3000238h ;3 255
03000224 ldrb r8,[r0,-r12] ;5 260
03000228 strb r8,[r0],1h ;4 264
0300022C subs r9,r9,1h ;1 265
03000230 bne Lxx_3000224h ;3 268
03000234 b Lxx_3000024h ;3 271
03000238 ldrb r8,[r0,-r12] ;5 276
0300023C strb r8,[r0],1h ;4 280
03000240 subs r9,r9,1h ;1 281
03000244 bne Lxx_300023Ch ;3 284
03000248 b Lxx_3000024h ;3 287
0300024C cmp r10,0h ;1 288
03000250 ldreq r6,[r1],4h ;8 296
03000254 moveq r10,20h ;1 297
03000258 mov r11,r8 ;1 298
0300025C cmp r11,r10 ;1 299
03000260 movhi r11,r10 ;1 300
03000264 rsb r7,r11,20h ;1 301
03000268 mov r7,r6,lsr r7 ;2 303
0300026C mov r6,r6,lsl r11 ;2 305
03000270 sub r10,r10,r11 ;1 306
03000274 subs r8,r8,r11 ;1 307
03000278 bxeq r14 ;3 310
0300027C ldr r6,[r1],4h ;8 318
03000280 rsb r10,r8,20h ;1 319
03000284 mov r11,r6,lsr r10 ;2 321
03000288 add r7,r11,r7,lsl r8 ;2 323
0300028C mov r6,r6,lsl r8 ;2 325
03000290 bx r14 ;3 328
03000294 pop r4-r11,r14 ;11 339
03000298 bx r14 ;3 342
0300029C push r4-r6 ;4 346
030002A0 mov r12,0FFh ;1 347
030002A4 ldr r4,[r1],4h ;8 355
030002A8 ands r5,r12,r4,lsr 18h ;1 356
030002AC ldrbne r5,[r2,r5] ;5 361
030002B0 ands r6,r12,r4,lsr 10h ;1 362
030002B4 ldrbne r6,[r2,r6] ;3 365
030002B8 orr r5,r6,r5,lsl 8h ;1 366
030002BC ands r6,r12,r4,lsr 8h ;1 367
030002C0 ldrbne r6,[r2,r6] ;3 370
030002C4 orr r5,r6,r5,lsl 8h ;1 371
030002C8 ands r6,r12,r4 ;1 372
030002CC ldrbne r6,[r2,r6] ;3 375
030002D0 orr r5,r6,r5,lsl 8h ;1 376
030002D4 str r5,[r0],4h ;7 383
030002D8 subs r3,r3,4h ;1 384
030002DC bne Lxx_30002A4h ;3 387
030002E0 pop r4-r6 ;5 392
030002E4 bx r14 ;3 395
030002E8 ???? ;4 399
030002EC andeq r0,r0,r15,ror r2 ;2 401
030002F0 push r4,r5 ;3 404
030002F4 ldr r2,[r0,34h] ;8 412
030002F8 ldr r0,[r0,24h] ;8 420
030002FC sub r0,r0,4h ;1 421
03000300 mov r4,0FFh ;1 422
03000304 subs r2,r2,4h ;1 423
03000308 bmi Lxx_3000340h ;3 426
0300030C add r0,r0,4h ;1 427
03000310 ldr r3,[r1],4h ;8 435
03000314 cmp r3,0h ;1 436
03000318 beq Lxx_3000304h ;3 439```
