8687f3f8f4
Thanks to Kyle Lemons for the inspiration and original design. The implementation in this commit is very different however, building on top of the software vectoring needed in RISC-V. The result is a flexible interrupt handler that does not take up any RAM for configuration.
63 строки
1,4 КиБ
Go
63 строки
1,4 КиБ
Go
// +build gameboyadvance
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package machine
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import (
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"image/color"
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"runtime/volatile"
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"unsafe"
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)
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// Interrupt numbers as used on the GameBoy Advance. Register them with
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// runtime/interrupt.New.
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const (
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IRQ_VBLANK = 0
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IRQ_HBLANK = 1
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IRQ_VCOUNT = 2
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IRQ_TIMER0 = 3
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IRQ_TIMER1 = 4
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IRQ_TIMER2 = 5
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IRQ_TIMER3 = 6
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IRQ_COM = 7
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IRQ_DMA0 = 8
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IRQ_DMA1 = 9
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IRQ_DMA2 = 10
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IRQ_DMA3 = 11
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IRQ_KEYPAD = 12
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IRQ_GAMEPAK = 13
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)
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// Make it easier to directly write to I/O RAM.
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var ioram = (*[0x400]volatile.Register8)(unsafe.Pointer(uintptr(0x04000000)))
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type PinMode uint8
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// Set has not been implemented.
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func (p Pin) Set(value bool) {
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// do nothing
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}
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var Display = FramebufDisplay{(*[160][240]volatile.Register16)(unsafe.Pointer(uintptr(0x06000000)))}
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type FramebufDisplay struct {
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port *[160][240]volatile.Register16
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}
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func (d FramebufDisplay) Configure() {
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// Write into the I/O registers, setting video display parameters.
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ioram[0].Set(0x03) // Use video mode 3 (in BG2, a 16bpp bitmap in VRAM)
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ioram[1].Set(0x04) // Enable BG2 (BG0 = 1, BG1 = 2, BG2 = 4, ...)
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}
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func (d FramebufDisplay) Size() (x, y int16) {
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return 240, 160
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}
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func (d FramebufDisplay) SetPixel(x, y int16, c color.RGBA) {
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d.port[y][x].Set(uint16(c.R)&0x1f | uint16(c.G)&0x1f<<5 | uint16(c.B)&0x1f<<10)
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}
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func (d FramebufDisplay) Display() error {
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// Nothing to do here.
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return nil
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}
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