git.joshuawise.com / fpgaboy.git / blame
| Commit | Line | Data |
|---|---|---|
| 49c326da | 1 | SECTION "boot", HOME[$0] |
| 1eefdc8e | 2 | boot: ld a, $AA |
| 49c326da | 3 | ld [$FF51], A ; Poke the LEDs |
| 1eefdc8e JW |
4 | |
| 5 | ld sp, $FFFE | |
| 6 | ||
| 7 | ld hl, signon | |
| 8 | call puts | |
| 49c326da | 9 | |
| 298e8085 JW |
10 | .wait: ld a, [$FF53] |
| 11 | and $02 | |
| 12 | jr z, .nodata | |
| 13 | ld a, [$FF52] | |
| 14 | ld [$FF51], a | |
| 49c326da | 15 | |
| 298e8085 JW |
16 | cp $1B ; Escape |
| 17 | jp z, .cbc | |
| 18 | ld [$FF52], a | |
| 19 | .cbc: call z, bootcmd | |
| 20 | ||
| 21 | .nodata: ld a, [$FF51] | |
| 1eefdc8e JW |
22 | cp $00 |
| 23 | jr nz, .wait | |
| 24 | ||
| 298e8085 | 25 | doboot: xor a |
| 1eefdc8e JW |
26 | ld h, a |
| 27 | ld l, a | |
| 28 | ld [hl], $01 ; Select the GB boot rom | |
| 29 | ||
| 30 | ld a, $55 | |
| 31 | ld [c], a | |
| 32 | ||
| 33 | ld hl, booting | |
| 34 | call puts | |
| 35 | ||
| 36 | rst $00 ; Boot | |
| 37 | ||
| 298e8085 JW |
38 | signon: |
| 39 | db $0D,$0A,$1B,"[1mFPGABoy Boot ROM",$1B,"[0m",$0D,$0A,0 | |
| 40 | booting: | |
| 41 | db "Booting...",$0D,$0A,0 | |
| 42 | ||
| 1eefdc8e JW |
43 | putc: |
| 44 | ld c, $53 | |
| 45 | push af | |
| 46 | .waitport: | |
| 47 | ld a,[c] | |
| 298e8085 | 48 | and $01 |
| 1eefdc8e JW |
49 | jr nz,.waitport |
| 50 | pop af | |
| 51 | ld [$FF52],a | |
| 52 | ret | |
| 53 | ||
| 54 | puts: | |
| 55 | ld a, [hli] | |
| 56 | cp $00 | |
| 57 | ret z | |
| 58 | call putc | |
| 59 | jr puts | |
| 60 | ||
| 298e8085 JW |
61 | getc: |
| 62 | ld a, [$FF53] | |
| 63 | and $02 | |
| 64 | jr z, getc | |
| 65 | ld a, [$FF52] | |
| 66 | ret | |
| 1eefdc8e | 67 | |
| 298e8085 JW |
68 | bootcmd: |
| 69 | call getc | |
| 70 | cp $56 ;V | |
| 71 | jr z,.version | |
| 72 | cp $41 ;A | |
| 73 | jr z,.addr | |
| 74 | cp $44 ;D | |
| 75 | jr z,.data | |
| 76 | cp $50 ;P | |
| 77 | jr z,.prog | |
| 78 | cp $42 ;B | |
| 79 | jr z,doboot | |
| 80 | cp $1B | |
| 81 | jr z,bootcmd ; If you keep yelling, you're bound to get the thing's attention. | |
| 82 | ld a, $3f ;? | |
| 83 | jr putc | |
| 84 | .version: | |
| 85 | ld hl, .verstr | |
| 86 | jr puts | |
| 87 | .verstr: | |
| 88 | db "V1.00",0 | |
| 89 | .addr: | |
| 90 | call getc | |
| 91 | ld [$FF60], A | |
| 92 | call getc | |
| 93 | ld [$FF61], A | |
| 94 | call getc | |
| 95 | ld [$FF62], A | |
| 96 | ld A, $41 ;A | |
| 97 | jr putc | |
| 98 | .data: | |
| 99 | call getc ; byte count | |
| 100 | ld c, a | |
| bf3f2c5f JW |
101 | .dl: dec c |
| 102 | jr z, .done | |
| 103 | call getc | |
| 298e8085 | 104 | ld [$FF63], A |
| bf3f2c5f JW |
105 | jr .dl |
| 106 | .done: ld A, $44 ;D | |
| 107 | jr putc | |
| 108 | ||
| 298e8085 | 109 | .prog: |
| efc8cc5d JW |
110 | ld hl, $D800 |
| 111 | ld c, $00 | |
| 298e8085 | 112 | .pl: dec c |
| bf3f2c5f | 113 | jp z, .progboot |
| 298e8085 JW |
114 | call getc |
| 115 | ld [hli], a | |
| 116 | jr .pl | |
| bf3f2c5f JW |
117 | .progboot: |
| 118 | ld a, $50 ;P | |
| 119 | call putc | |
| efc8cc5d | 120 | jp $D800 |
| 298e8085 | 121 | |
| 49c326da JW |
122 | SECTION "a", HOME[$100] |
| 123 | nop ; Make sure we don't overflow. | |
| 124 |