89 lines
1.8 KiB
Go
89 lines
1.8 KiB
Go
package izapple2
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import (
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"fmt"
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)
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type memoryRange struct {
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base uint16
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data []uint8
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name string
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}
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type memoryRangeROM struct {
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memoryRange
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pageOffset uint16
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pages uint8
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}
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func newMemoryRange(base uint16, data []uint8, name string) *memoryRange {
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var m memoryRange
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m.base = base
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m.data = data
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m.setBase(base)
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m.name = name
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return &m
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}
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func newMemoryRangeROM(base uint16, data []uint8, name string) *memoryRangeROM {
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return newMemoryRangePagedROM(base, data, name, 1)
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}
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func newMemoryRangePagedROM(base uint16, data []uint8, name string, pages uint8) *memoryRangeROM {
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var m memoryRangeROM
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m.base = base
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m.data = data
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m.name = name
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m.pages = pages
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return &m
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}
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func (m *memoryRange) setBase(base uint16) {
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m.base = base
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}
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func (m *memoryRange) peek(address uint16) uint8 {
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return m.data[address-m.base]
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}
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func (m *memoryRange) poke(address uint16, value uint8) {
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m.data[address-m.base] = value
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}
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func (m *memoryRange) subRange(a, b uint16) []uint8 {
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return m.data[a-m.base : b-m.base]
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}
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func (m *memoryRangeROM) setPage(page uint8) {
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pageSize := len(m.data) / int(m.pages)
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m.pageOffset = uint16(int(page%m.pages) * pageSize)
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}
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func (m *memoryRangeROM) getPage() uint8 {
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pageSize := len(m.data) / int(m.pages)
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return uint8(m.pageOffset / uint16(pageSize))
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}
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func (m *memoryRangeROM) peek(address uint16) uint8 {
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return m.data[address-m.base+m.pageOffset]
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}
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func (m *memoryRangeROM) poke(address uint16, value uint8) {
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// Ignore
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}
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//lint:ignore U1000 this is used to write debug code
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func identifyMemory(m memoryHandler) string {
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ram, ok := m.(*memoryRange)
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if ok {
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return fmt.Sprintf("RAM 0x%04x %s", ram.base, ram.name)
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}
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rom, ok := m.(*memoryRangeROM)
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if ok {
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return fmt.Sprintf("ROM 0x%04x %s", rom.base, ram.name)
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}
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return ("Unknown memory")
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}
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