1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
#include "rockmacros.h"
#include "defs.h"
#include "cpu.h"
#include "hw.h"
#include "regs.h"
#include "lcd.h"
#include "mem.h"
#include "fastmem.h"
struct hw hw;
/*
* hw_interrupt changes the virtual interrupt lines included in the
* specified mask to the values the corresponding bits in i take, and
* in doing so, raises the appropriate bit of R_IF for any interrupt
* lines that transition from low to high.
*/
void hw_interrupt(byte i, byte mask)
{
byte oldif = R_IF;
i &= 0x1F & mask;
R_IF |= i & (hw.ilines ^ i);
/* FIXME - is this correct? not sure the docs understand... */
if ((R_IF & (R_IF ^ oldif) & R_IE) && cpu.ime) cpu.halt = 0;
/* if ((i & (hw.ilines ^ i) & R_IE) && cpu.ime) cpu.halt = 0; */
/* if ((i & R_IE) && cpu.ime) cpu.halt = 0; */
hw.ilines &= ~mask;
hw.ilines |= i;
}
/*
* hw_dma performs plain old memory-to-oam dma, the original dmg
* dma. Although on the hardware it takes a good deal of time, the cpu
* continues running during this mode of dma, so no special tricks to
* stall the cpu are necessary.
*/
void hw_dma(byte b)
{
int i;
addr a;
a = ((addr)b) << 8;
for (i = 0; i < 160; i++, a++)
lcd.oam.mem[i] = readb(a);
}
void hw_hdma_cmd(byte c)
{
int cnt;
addr sa;
int da;
/* Begin or cancel HDMA */
if ((hw.hdma|c) & 0x80)
{
hw.hdma = c;
R_HDMA5 = c & 0x7f;
return;
}
/* Perform GDMA */
sa = ((addr)R_HDMA1 << 8) | (R_HDMA2&0xf0);
da = 0x8000 | ((int)(R_HDMA3&0x1f) << 8) | (R_HDMA4&0xf0);
cnt = ((int)c)+1;
/* FIXME - this should use cpu time! */
/*cpu_timers(102 * cnt);*/
cnt <<= 4;
while (cnt--)
writeb(da++, readb(sa++));
R_HDMA1 = sa >> 8;
R_HDMA2 = sa & 0xF0;
R_HDMA3 = 0x1F & (da >> 8);
R_HDMA4 = da & 0xF0;
R_HDMA5 = 0xFF;
}
void hw_hdma(void)
{
int cnt;
addr sa;
int da;
sa = ((addr)R_HDMA1 << 8) | (R_HDMA2&0xf0);
da = 0x8000 | ((int)(R_HDMA3&0x1f) << 8) | (R_HDMA4&0xf0);
cnt = 16;
while (cnt--)
writeb(da++, readb(sa++));
R_HDMA1 = sa >> 8;
R_HDMA2 = sa & 0xF0;
R_HDMA3 = 0x1F & (da >> 8);
R_HDMA4 = da & 0xF0;
R_HDMA5--;
hw.hdma--;
}
/*
* pad_refresh updates the P1 register from the pad states, generating
* the appropriate interrupts (by quickly raising and lowering the
* interrupt line) if a transition has been made.
*/
void pad_refresh()
{
byte oldp1;
oldp1 = R_P1;
R_P1 &= 0x30;
R_P1 |= 0xc0;
if (!(R_P1 & 0x10))
R_P1 |= (hw.pad & 0x0F);
if (!(R_P1 & 0x20))
R_P1 |= (hw.pad >> 4);
R_P1 ^= 0x0F;
if (oldp1 & ~R_P1 & 0x0F)
{
hw_interrupt(IF_PAD, IF_PAD);
hw_interrupt(0, IF_PAD);
}
}
/*
* These simple functions just update the state of a button on the
* pad.
*/
void pad_press(byte k)
{
if (hw.pad & k)
return;
hw.pad |= k;
pad_refresh();
}
void pad_release(byte k)
{
if (!(hw.pad & k))
return;
hw.pad &= ~k;
pad_refresh();
}
void pad_set(byte k, int st)
{
st ? pad_press(k) : pad_release(k);
}
void hw_reset()
{
hw.ilines = hw.pad = 0;
memset(ram.hi, 0, sizeof ram.hi);
R_P1 = 0xFF;
R_LCDC = 0x91;
R_BGP = 0xFC;
R_OBP0 = 0xFF;
R_OBP1 = 0xFF;
R_SVBK = 0x01;
R_HDMA5 = 0xFF;
R_VBK = 0xFE;
}
|
