public release of panzgb

2025-11-24 13:37:49 +01:00
commit d08fbfe1aa
18 changed files with 3827 additions and 0 deletions
--- a/lib/gb-memory.c
+++ b/lib/gb-memory.c
@@ -0,0 +1,84 @@
+#include "gb-impl.h"
+
+/*This function assumes that the ROM is already loaded*/
+
+void setGbBanking(gb *cpu) {
+    switch (cpu->cartridge[0x147]) {
+    case 1:
+    case 2:
+    case 3:
+        cpu->ROMType = 1;
+        cpu->currentROMBank = 1;
+        cpu->changeBank = mbc1_changeBank;
+        break;
+
+    case 0x13:
+        cpu->ROMType = 3;
+        cpu->currentROMBank = 1;
+        cpu->changeBank = mbc3_changeBank;
+        break;
+    }
+    cpu->currentRAMBank = 0;
+}
+
+BYTE readMemory(gb *cpu, WORD addr) {
+    if ((addr >= 0x0000) && (addr <= 0x3FFF)) {
+        return cpu->cartridge[addr];
+    }
+    if ((addr >= 0x4000) && (addr <= 0x7FFF)) {
+        WORD t = addr - 0x4000;
+        return cpu->cartridge[t + (cpu->currentROMBank * 0x4000)];
+    }
+
+    else if ((addr >= 0xA000) && (addr <= 0xBFFF)) {
+        WORD t = addr - 0xA000;
+        return cpu->RAMBank[t + (cpu->currentRAMBank * 0x2000)];
+    } else if (addr == 0xFF00)
+        return getKeypad(cpu);
+
+    return cpu->memory[addr];
+}
+
+/*This function is necessary for replicate the ECHO (E000-FDFF) area*/
+
+void writeMemory(gb *cpu, WORD addr, BYTE data) {
+    /*This part is mapped on the rom, so read-only*/
+    if (addr < 0x8000) {
+        cpu->changeBank(cpu, addr, data);
+    }
+
+    else if ((addr >= 0xA000) && (addr < 0xC000)) {
+        if (cpu->isRAMEnable != 0) {
+            WORD t = addr - 0xA000;
+            cpu->RAMBank[t + (cpu->currentRAMBank * 0x2000)] = data;
+        }
+    }
+
+    else if ((addr >= 0xE000) && (addr < 0xFE00)) {
+        cpu->memory[addr] = data;
+        writeMemory(cpu, addr - 0x2000, data);
+    }
+
+    /*Not usable */
+    else if ((addr >= 0xFEA0) && (addr < 0xFEFF)) {
+    }
+
+    else if (addr == TIMER_CONTROLLER) {
+        BYTE freq = readMemory(cpu, TIMER_CONTROLLER) & 0x3;
+        cpu->memory[TIMER_CONTROLLER] = data;
+        BYTE newfreq = readMemory(cpu, TIMER_CONTROLLER) & 0x3;
+
+        if (freq != newfreq)
+            setTimerFreq(cpu);
+    } else if (addr == DIVIDER_TIMER)
+        cpu->memory[DIVIDER_TIMER] = 0;
+    else if (addr == LCD_SCANLINE_ADRR)
+        cpu->memory[LCD_SCANLINE_ADRR] = 0;
+    else if (addr == DMA_ADRR)
+        DMATransfert(cpu, data);
+    else if((addr >= 0xFF10) && (addr <= 0xFF3F)){
+        writeSoundRegistry(cpu, addr, data);
+    }
+    else
+        cpu->memory[addr] = data;
+}