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Implement F0000-FFFFF shadowing on the OPTi 291

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The datasheet only gave a small reference to it in passing. Port 92 is also implemented as it is also present on the 291.
This commit is contained in:
nerd73
2020-07-08 01:41:18 -06:00
parent 2b06dbc10b
commit 263c48a49b
1 changed files with 21 additions and 10 deletions
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31
src/chipset/opti291.c
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@@ -35,33 +35,41 @@ typedef struct
{
uint8_t index,
regs[256];
port_92_t *port_92;
} opti291_t;
static void opti291_recalc(opti291_t *dev)
{
uint32_t base;
uint32_t i, shflags, write = 0;
uint32_t i, shflags, write, writef = 0;
writef = (dev->regs[0x27] & 0x80) ? MEM_WRITE_DISABLED : MEM_WRITE_INTERNAL;
if (!(dev->regs[0x23] & 0x40))
mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | writef);
else
mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTANY | writef);
for (i = 0; i < 4; i++) {
base = 0xe0000 + (i << 14);
shflags = (dev->regs[0x24] & (1 << (i+4))) ? MEM_READ_INTERNAL : MEM_READ_EXTANY;
shflags |= (dev->regs[0x24] & (1 << (i))) ? write : MEM_WRITE_EXTANY;
write = (dev->regs[0x27] & 0x40) ? MEM_WRITE_DISABLED : MEM_WRITE_INTERNAL;
write = (dev->regs[0x24] & (1 << i)) ? MEM_WRITE_INTERNAL : MEM_WRITE_EXTANY;
shflags |= (dev->regs[0x27] & 0x40) ? MEM_WRITE_DISABLED : write;
mem_set_mem_state(base, 0x4000, shflags);
}
for (i = 0; i < 4; i++) {
base = 0xd0000 + (i << 14);
shflags = (dev->regs[0x25] & (1 << (i+4))) ? MEM_READ_INTERNAL : MEM_READ_EXTANY;
shflags |= (dev->regs[0x25] & (1 << (i))) ? write : MEM_WRITE_EXTANY;
write = (dev->regs[0x27] & 0x20) ? MEM_WRITE_DISABLED : MEM_WRITE_INTERNAL;
write = (dev->regs[0x25] & (1 << i)) ? MEM_WRITE_INTERNAL : MEM_WRITE_EXTANY;
shflags |= (dev->regs[0x27] & 0x20) ? MEM_WRITE_DISABLED : write;
mem_set_mem_state(base, 0x4000, shflags);
}
for (i = 0; i < 4; i++) {
base = 0xc0000 + (i << 14);
shflags = (dev->regs[0x26] & (1 << (i+4))) ? MEM_READ_INTERNAL : MEM_READ_EXTANY;
shflags |= (dev->regs[0x26] & (1 << i)) ? write : MEM_WRITE_EXTANY;
write = (dev->regs[0x27] & 0x10) ? MEM_WRITE_DISABLED : MEM_WRITE_INTERNAL;
write = (dev->regs[0x26] & (1 << i)) ? MEM_WRITE_INTERNAL : MEM_WRITE_EXTANY;
shflags |= (dev->regs[0x27] & 0x10) ? MEM_WRITE_DISABLED : write;
mem_set_mem_state(base, 0x4000, shflags);
}
flushmmucache();
@@ -83,10 +91,11 @@ opti291_write(uint16_t addr, uint8_t val, void *priv)
case 0x21:
cpu_update_waitstates();
break;
case 0x23:
case 0x24:
case 0x25:
case 0x26:
case 0x27:
case 0x27:
opti291_recalc(dev);
break;
}
@@ -103,6 +112,7 @@ opti291_read(uint16_t addr, void *priv)
switch (addr) {
case 0x24:
// pclog("OPTi 291: read from dev->regs[%02x]\n", dev->index);
ret = dev->regs[dev->index];
break;
}
@@ -128,7 +138,8 @@ opti291_init(const device_t *info)
io_sethandler(0x022, 0x0001, opti291_read, NULL, NULL, opti291_write, NULL, NULL, dev);
io_sethandler(0x024, 0x0001, opti291_read, NULL, NULL, opti291_write, NULL, NULL, dev);
dev->regs[0x23] = 0x40;
dev->port_92 = device_add(&port_92_device);
opti291_recalc(dev);
return dev;