mirror of
https://github.com/freewilll/apple2-go.git
synced 2024-09-29 14:57:33 +00:00
5d1c25a724
Basic memory management has been implemented since $c100-$cfff needs flipping with soft switches during Apple //e boot. All memory reads & writes now go through the MMU. Memory is also dynamically allocated and associated with the CPU state.
97 lines
2.4 KiB
Go
97 lines
2.4 KiB
Go
package cpu
|
|
|
|
import (
|
|
"fmt"
|
|
"strings"
|
|
)
|
|
|
|
func printFlag(p byte, flag uint8, code string) {
|
|
if (p & flag) == 0 {
|
|
fmt.Print(code)
|
|
} else {
|
|
fmt.Printf("%s", strings.ToUpper(code))
|
|
}
|
|
}
|
|
|
|
func printInstruction(s *State, instruction string) {
|
|
fmt.Printf("%04x %-24s A=%02x X=%02x Y=%02x S=%02x P=%02x ",
|
|
s.PC,
|
|
instruction,
|
|
s.A,
|
|
s.X,
|
|
s.Y,
|
|
s.SP,
|
|
s.P,
|
|
)
|
|
|
|
printFlag(s.P, CpuFlagN, "n")
|
|
printFlag(s.P, CpuFlagV, "v")
|
|
fmt.Print("-") // CpuFlagR flag that's always 1
|
|
printFlag(s.P, CpuFlagB, "b")
|
|
printFlag(s.P, CpuFlagD, "d")
|
|
printFlag(s.P, CpuFlagI, "i")
|
|
printFlag(s.P, CpuFlagZ, "z")
|
|
printFlag(s.P, CpuFlagC, "c")
|
|
|
|
fmt.Println("")
|
|
}
|
|
|
|
func PrintInstruction(s *State) {
|
|
opcodeValue := (*s.MemoryMap)[uint8((s.PC)>>8)][uint8((s.PC)&0xff)]
|
|
opcode := OpCodes[opcodeValue]
|
|
mnemonic := opcode.Mnemonic
|
|
size := opcode.AddressingMode.OperandSize
|
|
stringFormat := opcode.AddressingMode.StringFormat
|
|
|
|
var value uint16
|
|
if size == 0 {
|
|
printInstruction(s, fmt.Sprintf("%02x %s", opcodeValue, mnemonic))
|
|
return
|
|
}
|
|
|
|
var opcodes string
|
|
var suffix string
|
|
|
|
if opcode.AddressingMode.Mode == AmRelative {
|
|
value = uint16((*s.MemoryMap)[uint8((s.PC+1)>>8)][uint8((s.PC+1)&0xff)])
|
|
var relativeAddress uint16
|
|
if (value & 0x80) == 0 {
|
|
relativeAddress = s.PC + 2 + uint16(value)
|
|
} else {
|
|
relativeAddress = s.PC + 2 + uint16(value) - 0x100
|
|
}
|
|
|
|
suffix = fmt.Sprintf(stringFormat, relativeAddress)
|
|
opcodes = fmt.Sprintf("%02x %02x ", opcodeValue, value)
|
|
} else if size == 1 {
|
|
value = uint16((*s.MemoryMap)[uint8((s.PC+1)>>8)][uint8((s.PC+1)&0xff)])
|
|
suffix = fmt.Sprintf(stringFormat, value)
|
|
opcodes = fmt.Sprintf("%02x %02x ", opcodeValue, value)
|
|
} else if size == 2 {
|
|
lsb := (*s.MemoryMap)[uint8((s.PC+1)>>8)][uint8((s.PC+1)&0xff)]
|
|
msb := (*s.MemoryMap)[uint8((s.PC+2)>>8)][uint8((s.PC+2)&0xff)]
|
|
value = uint16(lsb) + uint16(msb)*0x100
|
|
suffix = fmt.Sprintf(stringFormat, value)
|
|
opcodes = fmt.Sprintf("%02x %02x %02x ", opcodeValue, lsb, msb)
|
|
}
|
|
|
|
printInstruction(s, fmt.Sprintf("%s %s %s", opcodes, mnemonic, suffix))
|
|
}
|
|
|
|
func DumpMemory(s *State, offset uint16) {
|
|
var i uint16
|
|
for i = 0; i < 0x100; i++ {
|
|
if (i & 0xf) == 8 {
|
|
fmt.Print(" ")
|
|
}
|
|
if (i & 0xf) == 0 {
|
|
if i > 0 {
|
|
fmt.Print("\n")
|
|
}
|
|
fmt.Printf("%04x ", offset+i)
|
|
}
|
|
fmt.Printf(" %02x", (*s.MemoryMap)[uint8((offset+i)>>8)][uint8((offset+i)&0xff)])
|
|
}
|
|
fmt.Print("\n")
|
|
}
|