52 lines
1.1 KiB
C++
52 lines
1.1 KiB
C++
#include "memory/bootrom_overlay.h"
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BootRom::BootRom(Mem_device* lowmem, Mem_device* highmem, Mem_device* backend)
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: lowmem(lowmem), highmem(highmem), backend(backend), enabled(true),
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lowrange(0x0000, 0x00FF), highrange(0x0200, 0x08FF)
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{}
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void BootRom::enable()
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{
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enabled = true;
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}
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void BootRom::disable()
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{
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enabled = false;
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}
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void BootRom::write8(u16 addr, u8 data)
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{
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if(enabled && (lowrange.contains(addr) || highrange.contains(addr)))
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return;
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backend->write8(addr, data);
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}
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u8 BootRom::read8(u16 addr)
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{
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if(enabled && lowrange.contains(addr))
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return lowmem->read8(addr);
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else if(enabled && highrange.contains(addr))
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return highmem->read8(addr);
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else
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return backend->read8(addr);
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}
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void BootRom::write16(u16 addr, u16 data)
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{
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if(enabled && (lowrange.contains(addr) || highrange.contains(addr)))
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return;
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backend->write16(addr, data);
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}
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u16 BootRom::read16(u16 addr)
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{
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if(enabled && lowrange.contains(addr))
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return lowmem->read16(addr);
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else if(enabled && highrange.contains(addr))
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return highmem->read16(addr);
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else
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return backend->read16(addr);
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}
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