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103 lines
3.8 KiB
Rust
103 lines
3.8 KiB
Rust
// Copyright (C) 2014 The 6502-rs Developers
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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// 1. Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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// 3. Neither the names of the copyright holders nor the names of any
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// contributors may be used to endorse or promote products derived from this
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// software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// POSSIBILITY OF SUCH DAMAGE.
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use address::{Address, AddressDiff};
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// JAM: We can probably come up with a better way to represent address ranges.
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// Address range type?
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//
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// // Address range -- inclusive on both sides
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// pub struct AddressRangeIncl {
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// begin: Address,
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// end: Address,
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// }
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const ADDR_LO_BARE: u16 = 0x0000;
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const ADDR_HI_BARE: u16 = 0xFFFF;
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pub const MEMORY_ADDRESS_LO: Address = Address(ADDR_LO_BARE);
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pub const MEMORY_ADDRESS_HI: Address = Address(ADDR_HI_BARE);
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pub const STACK_ADDRESS_LO: Address = Address(0x0100);
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pub const STACK_ADDRESS_HI: Address = Address(0x01FF);
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pub const IRQ_INTERRUPT_VECTOR_LO: Address = Address(0xFFFE);
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pub const IRQ_INTERRUPT_VECTOR_HI: Address = Address(0xFFFF);
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const MEMORY_SIZE: uint = (ADDR_HI_BARE - ADDR_LO_BARE) as uint + 1u;
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// FIXME: Should this use indirection for `bytes`?
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#[deriving(Copy)]
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pub struct Memory {
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bytes: [u8, ..MEMORY_SIZE]
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}
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impl Memory {
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pub fn new() -> Memory {
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Memory { bytes: [0, ..MEMORY_SIZE] }
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}
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pub fn get_byte(&self, address: Address) -> u8 {
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self.bytes[address.to_uint()]
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}
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pub fn get_byte_mut_ref(&mut self, address: Address) -> &mut u8 {
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&mut self.bytes[address.to_uint()]
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}
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pub fn get_slice(&self, Address(start): Address,
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AddressDiff(diff): AddressDiff) -> &[u8] {
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let start = start as uint;
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let diff = diff as uint;
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let end = start + diff;
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self.bytes.slice(start, end)
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}
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// Sets the byte at the given address to the given value and returns the
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// previous value at the address.
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pub fn set_byte(&mut self, address: Address, value: u8) -> u8 {
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let old_value = self.get_byte(address);
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self.bytes[address.to_uint()] = value;
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old_value
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}
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pub fn set_bytes(&mut self, Address(start): Address, values: &[u8]) {
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let start = start as uint;
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// This panics if the range is invalid
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let slice = self.bytes.slice_mut(start, start + values.len());
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// JAM: Is this the best way to do this copy?
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for (dest, src) in slice.iter_mut().zip(values.iter()) {
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*dest = *src;
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}
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}
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pub fn is_stack_address(address: &Address) -> bool {
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STACK_ADDRESS_LO <= *address && *address <= STACK_ADDRESS_HI
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}
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}
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