fxos/lib/memory.cpp

//---------------------------------------------------------------------------//
//  1100101 |_ mov #0, r4         __                                         //
//     11   |_ <0xb380 %5c4>     / _|_ _____ ___                             //
//     0110 |_ 3.50 -> 3.60     |  _\ \ / _ (_-<                             //
//          |_ base# + offset   |_| /_\_\___/__/                             //
//---------------------------------------------------------------------------//

#include <fxos/memory.h>
#include <stdexcept>
#include <array>

namespace FxOS {

MemoryArea MemoryArea::U0 = {0x00000000, 0x7fffffff, "U0"};
MemoryArea MemoryArea::P0 = {0x00000000, 0x7fffffff, "P0"};
MemoryArea MemoryArea::P1 = {0x80000000, 0x9fffffff, "P1"};
MemoryArea MemoryArea::P2 = {0xa0000000, 0xbfffffff, "P2"};
MemoryArea MemoryArea::P3 = {0xc0000000, 0xdfffffff, "P3"};
MemoryArea MemoryArea::P4 = {0xe0000000, 0xffffffff, "P4"};

//---
//  Fine memory region management
//---

MemoryRegion::MemoryRegion():
    name {"null"}, start {0x00000000}, end {0x00000000}, writable {false}
{
}

MemoryRegion::MemoryRegion(
    std::string name, uint32_t start, uint32_t end, bool writable):
    name {name},
    start {start}, end {end}, writable {writable}
{
    this->guess_flags();
}

uint32_t MemoryRegion::size() const noexcept
{
    return end - start;
}

MemoryArea MemoryRegion::area() const noexcept
{
    using Area = MemoryArea;
    static Area areas[5] = {Area::P4, Area::P3, Area::P2, Area::P1, Area::P0};

    for(int i = 0; i < 5; i++) {
        if(start >= areas[i].start)
            return areas[i];
    }

    return Area::P0;
}

void MemoryRegion::guess_flags() noexcept
{
    MemoryArea area = this->area();

    if(area == MemoryArea::U0 || area == MemoryArea::P0
        || area == MemoryArea::P3) {
        cacheable = true;
        mappable = true;
    }
    else if(area == MemoryArea::P1) {
        cacheable = true;
        mappable = false;
    }
    else if(area == MemoryArea::P2 || area == MemoryArea::P4) {
        cacheable = false;
        mappable = false;
    }
    else {
        cacheable = false;
        mappable = false;
    }
}

using R = MemoryRegion;

/* Basic memory regions */
// clang-format off
R const R::ROM      ("ROM",       0x80000000, 0x81ffffff, false);
R const R::ROM_P2   ("ROM_P2",    0xa0000000, 0xa07fffff, false);
R const R::RAM      ("RAM",       0x88000000, 0x881fffff, true);
R const R::RAM_P2   ("RAM_P2",    0xa8000000, 0xa81fffff, true);
R const R::RAM_8C   ("RAM_8C",    0x8c000000, 0x8c7fffff, true);
R const R::RAM_8C_P2("RAM_8C_P2", 0xac000000, 0xac7fffff, true);
R const R::RS       ("RS",        0xfd800000, 0xfd8007ff, true);
R const R::ILRAM    ("ILRAM",     0xe5200000, 0xe5203fff, true);
R const R::XRAM     ("XRAM",      0xe5007000, 0xe5008fff, true);
R const R::YRAM     ("YRAM",      0xe5017000, 0xe5018fff, true);
// clang-format on

std::array<MemoryRegion const *, 10> const MemoryRegion::m_all = {
    &R::ROM,
    &R::ROM_P2,
    &R::RAM,
    &R::RAM_P2,
    &R::RAM_8C,
    &R::RAM_8C_P2,
    &R::RS,
    &R::ILRAM,
    &R::XRAM,
    &R::YRAM,
};

std::array<MemoryRegion const *, 10> const &MemoryRegion::all()
{
    return m_all;
}

MemoryRegion const *MemoryRegion::region_for(uint32_t address)
{
    for(auto r: MemoryRegion::all()) {
        if(r->start <= address && address < r->end)
            return r;
    }
    return nullptr;
}

MemoryRegion const *MemoryRegion::region_for(MemoryRegion region)
{
    for(auto r: MemoryRegion::all()) {
        if(r->start <= region.start && region.end <= r->end)
            return r;
    }
    return nullptr;
}

MemoryRegion::MemoryRegion(std::string name): MemoryRegion()
{
    for(auto r: MemoryRegion::all()) {
        if(r->name == name) {
            *this = *r;
            return;
        }
    }
}

} /* namespace FxOS */