73 lines
1.6 KiB
Zig
73 lines
1.6 KiB
Zig
const std = @import("std");
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const Self = @This();
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state: State,
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id_mode: bool,
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set_bank: bool,
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prep_erase: bool,
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prep_write: bool,
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bank: u1,
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const State = enum {
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Ready,
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Set,
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Command,
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};
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pub fn read(self: *const Self, buf: []u8, idx: usize) u8 {
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return buf[self.address() + idx];
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}
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pub fn write(self: *Self, buf: []u8, idx: usize, byte: u8) void {
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buf[self.address() + idx] = byte;
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self.prep_write = false;
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}
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pub fn create() Self {
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return .{
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.state = .Ready,
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.id_mode = false,
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.set_bank = false,
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.prep_erase = false,
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.prep_write = false,
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.bank = 0,
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};
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}
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pub fn handleCommand(self: *Self, buf: []u8, byte: u8) void {
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switch (byte) {
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0x90 => self.id_mode = true,
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0xF0 => self.id_mode = false,
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0xB0 => self.set_bank = true,
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0x80 => self.prep_erase = true,
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0x10 => {
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@memset(buf, 0xFF);
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self.prep_erase = false;
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},
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0xA0 => self.prep_write = true,
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else => std.debug.panic("Unhandled Flash Command: 0x{X:0>2}", .{byte}),
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}
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self.state = .Ready;
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}
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pub fn shouldEraseSector(self: *const Self, addr: usize, byte: u8) bool {
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return self.state == .Command and self.prep_erase and byte == 0x30 and addr & 0xFFF == 0x000;
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}
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pub fn erase(self: *Self, buf: []u8, sector: usize) void {
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const start = self.address() + (sector & 0xF000);
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@memset(buf[start..][0..0x1000], 0xFF);
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self.prep_erase = false;
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self.state = .Ready;
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}
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/// Base Address
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inline fn address(self: *const Self) usize {
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return if (self.bank == 1) 0x10000 else @as(usize, 0);
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}
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