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Annotation of nono/vm/gvram.cpp, revision 1.1.1.10

1.1       root        1: //
                      2: // nono
1.1.1.3   root        3: // Copyright (C) 2020 nono project
                      4: // Licensed under nono-license.txt
1.1       root        5: //
                      6: 
                      7: //
                      8: // GVRAM
                      9: //
1.1.1.6   root       10: 
1.1       root       11: // GVRAM はワード単位でホストバイトオーダ配置なので、
                     12: // バイトアクセス時は HB() マクロを使用のこと。
                     13: 
1.1.1.6   root       14: #include "gvram.h"
                     15: #include "videoctlr.h"
                     16: 
1.1.1.8   root       17: // InsideOut p.135
                     18: static const busdata wait = busdata::Wait(9 * 40_nsec);
                     19: 
1.1.1.6   root       20: // コンストラクタ
1.1       root       21: GVRAMDevice::GVRAMDevice()
1.1.1.7   root       22:        : inherited(OBJ_GVRAM)
1.1       root       23: {
                     24: }
                     25: 
1.1.1.6   root       26: // デストラクタ
1.1       root       27: GVRAMDevice::~GVRAMDevice()
                     28: {
                     29: }
                     30: 
1.1.1.10! root       31: // 初期化
        !            32: bool
        !            33: GVRAMDevice::Init()
        !            34: {
        !            35:        uint devlen = 0x20'0000;        // XXX とりあえず
        !            36:        mem.reset(new(std::nothrow) uint8[devlen]);
        !            37:        if ((bool)mem == false) {
        !            38:                warnx("Cannot allocate %u bytes at %s", devlen, __method__);
        !            39:                return false;
        !            40:        }
        !            41: 
        !            42:        return true;
        !            43: }
        !            44: 
1.1.1.9   root       45: inline uint32
                     46: GVRAMDevice::Decoder(uint32 addr) const
1.1       root       47: {
1.1.1.9   root       48:        return addr - baseaddr;
1.1       root       49: }
                     50: 
1.1.1.8   root       51: busdata
1.1.1.9   root       52: GVRAMDevice::Read(busaddr addr)
1.1       root       53: {
1.1.1.9   root       54:        uint32 offset = Decoder(addr.Addr());
1.1.1.8   root       55:        busdata data;
1.1.1.9   root       56: 
                     57:        data = *(uint16 *)&mem[offset & ~1U];
1.1.1.8   root       58:        data |= wait;
1.1.1.9   root       59:        data |= BusData::Size2;
1.1.1.8   root       60:        return data;
1.1       root       61: }
                     62: 
1.1.1.8   root       63: busdata
1.1.1.9   root       64: GVRAMDevice::Write(busaddr addr, uint32 data)
1.1       root       65: {
1.1.1.9   root       66:        uint32 offset = Decoder(addr.Addr());
                     67:        uint32 reqsize = addr.GetSize();
                     68:        uint32 datasize = std::min(2 - (offset & 1U), reqsize);
                     69:        data >>= (reqsize - datasize) * 8;
                     70: 
                     71:        if (datasize == 1) {
                     72:                mem[HB(offset)] = data;
                     73:        } else {
                     74:                *(uint16 *)&mem[offset] = data;
                     75:        }
                     76: 
                     77:        busdata r = wait;
                     78:        r |= busdata::Size(datasize);
                     79:        return r;
1.1       root       80: }
                     81: 
1.1.1.8   root       82: busdata
1.1.1.9   root       83: GVRAMDevice::Peek1(uint32 addr)
1.1       root       84: {
1.1.1.9   root       85:        uint32 offset = Decoder(addr);
                     86:        return mem[HB(offset)];
1.1       root       87: }

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