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Switches to a target-centric view of shadowing.

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This commit is contained in:
Thomas Harte 2021-02-27 22:13:10 -05:00
parent 2a7ea9f57c
commit 7dcb0553e4
1 changed files with 55 additions and 50 deletions
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105
Machines/Apple/AppleIIgs/MemoryMap.hpp
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@ -234,11 +234,8 @@ class MemoryMap {
}
void set_speed_register(uint8_t value) {
const uint8_t diff = value ^ speed_register_;
speed_register_ = value;
if(diff & 0x10) {
set_shadowing();
}
enable_all_pages_shadowing = speed_register_ & 0x10;
}
void set_state_register(uint8_t value) {
@ -432,8 +429,6 @@ class MemoryMap {
//
// Completely distinct from the auxiliary and language card switches.
void set_shadowing() {
const bool inhibit_all_pages = !(speed_register_ & 0x10);
// Disables shadowing for the region starting from @c zone if @c flag is true;
// otherwise enables it.
#define apply(disable, zone) \
@ -455,26 +450,19 @@ class MemoryMap {
// The interpretations of how the overlapping high-res and super high-res inhibit
// bits apply used below is taken from The Apple IIgs Technical Reference, P. 178.
constexpr int shadow_shift = 10;
constexpr int auxiliary_offset = 0x10000 >> shadow_shift;
// Text Page 1, main and auxiliary — $0400–$0800.
apply(shadow_register_ & 0x01, 0x0004);
apply(shadow_register_ & 0x01, 0x0104);
// apply((shadow_register_ & 0x01) || inhibit_all_pages, 0x0204); // All other pages uses the same shadowing flags.
// apply((shadow_register_ & 0x01) || inhibit_all_pages, 0x0304);
assert_is_region(0x004, 0x008);
assert_is_region(0x104, 0x108);
assert_is_region(0x204, 0x208);
assert_is_region(0x304, 0x308);
for(size_t c = 0x0400 >> shadow_shift; c < 0x0800 >> shadow_shift; c++) {
is_shadowed[c] = is_shadowed[c+auxiliary_offset] = !(shadow_register_ & 0x01);
}
// Text Page 2, main and auxiliary — 0x0800–0x0c00.
// TODO: on a ROM03 machine only.
apply(shadow_register_ & 0x20, 0x0008);
apply(shadow_register_ & 0x20, 0x0108);
apply((shadow_register_ & 0x20) || inhibit_all_pages, 0x0208);
apply((shadow_register_ & 0x20) || inhibit_all_pages, 0x0308);
assert_is_region(0x008, 0x00c);
assert_is_region(0x108, 0x10c);
assert_is_region(0x208, 0x20c);
assert_is_region(0x308, 0x30c);
for(size_t c = 0x0800 >> shadow_shift; c < 0x0c00 >> shadow_shift; c++) {
is_shadowed[c] = is_shadowed[c+auxiliary_offset] = !(shadow_register_ & 0x20);
}
// Hi-res graphics Page 1, main and auxiliary — $2000–$4000;
// also part of the super high-res graphics page on odd pages.
@ -485,33 +473,24 @@ class MemoryMap {
// Odd test:
// (high-res graphics inhibit or auxiliary high res graphics inhibit) _and_ (super high-res inhibit).
//
apply(shadow_register_ & 0x02, 0x0020);
apply((shadow_register_ & 0x12) && (shadow_register_ & 0x08), 0x0120);
apply((shadow_register_ & 0x02) || inhibit_all_pages, 0x0220);
apply(((shadow_register_ & 0x12) && (shadow_register_ & 0x08)) || inhibit_all_pages, 0x0320);
assert_is_region(0x020, 0x040);
assert_is_region(0x120, 0x140);
assert_is_region(0x220, 0x240);
assert_is_region(0x320, 0x340);
for(size_t c = 0x2000 >> shadow_shift; c < 0x4000 >> shadow_shift; c++) {
is_shadowed[c] = !(shadow_register_ & 0x02);
is_shadowed[c+auxiliary_offset] = !(shadow_register_ & 0x12);
}
// Hi-res graphics Page 2, main and auxiliary — $4000–$6000;
// also part of the super high-res graphics page.
//
// Test applied: much like that for page 1.
apply(shadow_register_ & 0x04, 0x0040);
apply((shadow_register_ & 0x14) && (shadow_register_ & 0x08), 0x0140);
apply((shadow_register_ & 0x04) || inhibit_all_pages, 0x0240);
apply(((shadow_register_ & 0x14) && (shadow_register_ & 0x08)) || inhibit_all_pages, 0x0340);
assert_is_region(0x040, 0x060);
assert_is_region(0x140, 0x160);
assert_is_region(0x240, 0x260);
assert_is_region(0x340, 0x360);
for(size_t c = 0x4000 >> shadow_shift; c < 0x6000 >> shadow_shift; c++) {
is_shadowed[c] = !(shadow_register_ & 0x04);
is_shadowed[c+auxiliary_offset] = !(shadow_register_ & 0x14);
}
// Residue of Super Hi-Res — $6000–$a000 (odd pages only).
apply(shadow_register_ & 0x08, 0x0160);
apply((shadow_register_ & 0x08) || inhibit_all_pages, 0x0360);
assert_is_region(0x160, 0x1a0);
assert_is_region(0x360, 0x3a0);
for(size_t c = 0x6000 >> shadow_shift; c < 0xa000 >> shadow_shift; c++) {
is_shadowed[c+auxiliary_offset] = !(shadow_register_ & 0x08);
}
#undef apply
}
@ -566,6 +545,23 @@ class MemoryMap {
set_shadowing();
}
void print_state() {
uint8_t region = region_map[0];
uint32_t start = 0;
for(uint32_t top = 0; top < 65536; top++) {
if(region_map[top] == region) continue;
printf("%06x -> %06x\t", start, top << 8);
printf("%c%c\n",
(regions[region_map[top] - 1].flags & Region::Is1Mhz) ? '1' : '-',
(regions[region_map[top] - 1].flags & Region::IsIO) ? 'x' : '-'
);
start = top << 8;
region = region_map[top];
}
}
#undef assert_is_region
public:
@ -586,29 +582,38 @@ class MemoryMap {
uint8_t flags = 0;
enum Flag: uint8_t {
IsShadowed = 1 << 0, // Writes should be shadowed to [end of RAM - 128kb + base offset].
Is1Mhz = 1 << 1, // Both reads and writes should be synchronised with the 1Mhz clock.
IsIO = 1 << 2, // Indicates that this region should be checked for soft switches, registers, etc;
// usurps the shadowed flags.
Is1Mhz = 1 << 0, // Both reads and writes should be synchronised with the 1Mhz clock.
IsIO = 1 << 1, // Indicates that this region should be checked for soft switches, registers, etc.
};
};
std::array<Region, 64> regions; // The assert above ensures that this is large enough; there's no
// doctrinal reason for it to be whatever size it is now, just
// adjust as required.
// Contains a flag for every page in the final 128kb of memory, indicating whether it is
// currently subject to shadowing.
std::bitset<128> is_shadowed;
bool enable_all_pages_shadowing = true;
};
// TODO: branching below on region.read/write is predicated on the idea that extra scratch space
// would be less efficient. Verify that?
#define MemoryMapRegion(map, address) map.regions[map.region_map[address >> 8]]
#define MemoryMapRead(region, address, value) *value = region.read ? region.read[address] : 0xff
// TODO: somehow eliminate bank 0/1 conditional in IsShadowed.
#define MemoryMapRegion(map, address) map.regions[map.region_map[address >> 8]]
#define IsShadowed(map, region, address) map.is_shadowed[((&region.write[address] - map.ram_base) >> 10) & 127] && (map.enable_all_pages_shadowing || (address < 0x2'0000))
#define MemoryMapRead(region, address, value) *value = region.read ? region.read[address] : 0xff
#define MemoryMapWrite(map, region, address, value) \
if(region.write) { \
region.write[address] = *value; \
const auto is_shadowed = region.flags & MemoryMap::Region::IsShadowed; \
map.shadow_base[is_shadowed][(&region.write[address] - map.ram_base) & map.shadow_mask[is_shadowed]] = *value; \
const bool _mm_is_shadowed = IsShadowed(map, region, address); \
map.shadow_base[is_shadowed][(&region.write[address] - map.ram_base) & map.shadow_mask[_mm_is_shadowed]] = *value; \
}
// const auto is_shadowed = region.flags & MemoryMap::Region::IsShadowed; \
// map.shadow_base[is_shadowed][(&region.write[address] - map.ram_base) & map.shadow_mask[is_shadowed]] = *value; \
// Quick notes on ::IsShadowed contortions:
//
// The objective is to support shadowing: