kind of in the middle of the checksum stuff
This commit is contained in:
@@ -0,0 +1,3 @@
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||||
.zig-cache/
|
||||
zig-out/
|
||||
*.o
|
||||
@@ -0,0 +1,156 @@
|
||||
const std = @import("std");
|
||||
|
||||
// Although this function looks imperative, it does not perform the build
|
||||
// directly and instead it mutates the build graph (`b`) that will be then
|
||||
// executed by an external runner. The functions in `std.Build` implement a DSL
|
||||
// for defining build steps and express dependencies between them, allowing the
|
||||
// build runner to parallelize the build automatically (and the cache system to
|
||||
// know when a step doesn't need to be re-run).
|
||||
pub fn build(b: *std.Build) void {
|
||||
// Standard target options allow the person running `zig build` to choose
|
||||
// what target to build for. Here we do not override the defaults, which
|
||||
// means any target is allowed, and the default is native. Other options
|
||||
// for restricting supported target set are available.
|
||||
const target = b.standardTargetOptions(.{});
|
||||
// Standard optimization options allow the person running `zig build` to select
|
||||
// between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
|
||||
// set a preferred release mode, allowing the user to decide how to optimize.
|
||||
const optimize = b.standardOptimizeOption(.{});
|
||||
// It's also possible to define more custom flags to toggle optional features
|
||||
// of this build script using `b.option()`. All defined flags (including
|
||||
// target and optimize options) will be listed when running `zig build --help`
|
||||
// in this directory.
|
||||
|
||||
// This creates a module, which represents a collection of source files alongside
|
||||
// some compilation options, such as optimization mode and linked system libraries.
|
||||
// Zig modules are the preferred way of making Zig code available to consumers.
|
||||
// addModule defines a module that we intend to make available for importing
|
||||
// to our consumers. We must give it a name because a Zig package can expose
|
||||
// multiple modules and consumers will need to be able to specify which
|
||||
// module they want to access.
|
||||
const mod = b.addModule("rom_dump", .{
|
||||
// The root source file is the "entry point" of this module. Users of
|
||||
// this module will only be able to access public declarations contained
|
||||
// in this file, which means that if you have declarations that you
|
||||
// intend to expose to consumers that were defined in other files part
|
||||
// of this module, you will have to make sure to re-export them from
|
||||
// the root file.
|
||||
.root_source_file = b.path("src/root.zig"),
|
||||
// Later on we'll use this module as the root module of a test executable
|
||||
// which requires us to specify a target.
|
||||
.target = target,
|
||||
});
|
||||
|
||||
// Here we define an executable. An executable needs to have a root module
|
||||
// which needs to expose a `main` function. While we could add a main function
|
||||
// to the module defined above, it's sometimes preferable to split business
|
||||
// logic and the CLI into two separate modules.
|
||||
//
|
||||
// If your goal is to create a Zig library for others to use, consider if
|
||||
// it might benefit from also exposing a CLI tool. A parser library for a
|
||||
// data serialization format could also bundle a CLI syntax checker, for example.
|
||||
//
|
||||
// If instead your goal is to create an executable, consider if users might
|
||||
// be interested in also being able to embed the core functionality of your
|
||||
// program in their own executable in order to avoid the overhead involved in
|
||||
// subprocessing your CLI tool.
|
||||
//
|
||||
// If neither case applies to you, feel free to delete the declaration you
|
||||
// don't need and to put everything under a single module.
|
||||
const exe = b.addExecutable(.{
|
||||
.name = "rom_dump",
|
||||
.root_module = b.createModule(.{
|
||||
// b.createModule defines a new module just like b.addModule but,
|
||||
// unlike b.addModule, it does not expose the module to consumers of
|
||||
// this package, which is why in this case we don't have to give it a name.
|
||||
.root_source_file = b.path("src/main.zig"),
|
||||
// Target and optimization levels must be explicitly wired in when
|
||||
// defining an executable or library (in the root module), and you
|
||||
// can also hardcode a specific target for an executable or library
|
||||
// definition if desireable (e.g. firmware for embedded devices).
|
||||
.target = target,
|
||||
.optimize = optimize,
|
||||
// List of modules available for import in source files part of the
|
||||
// root module.
|
||||
.imports = &.{
|
||||
// Here "rom_dump" is the name you will use in your source code to
|
||||
// import this module (e.g. `@import("rom_dump")`). The name is
|
||||
// repeated because you are allowed to rename your imports, which
|
||||
// can be extremely useful in case of collisions (which can happen
|
||||
// importing modules from different packages).
|
||||
.{ .name = "rom_dump", .module = mod },
|
||||
},
|
||||
}),
|
||||
});
|
||||
|
||||
// This declares intent for the executable to be installed into the
|
||||
// install prefix when running `zig build` (i.e. when executing the default
|
||||
// step). By default the install prefix is `zig-out/` but can be overridden
|
||||
// by passing `--prefix` or `-p`.
|
||||
b.installArtifact(exe);
|
||||
|
||||
// This creates a top level step. Top level steps have a name and can be
|
||||
// invoked by name when running `zig build` (e.g. `zig build run`).
|
||||
// This will evaluate the `run` step rather than the default step.
|
||||
// For a top level step to actually do something, it must depend on other
|
||||
// steps (e.g. a Run step, as we will see in a moment).
|
||||
const run_step = b.step("run", "Run the app");
|
||||
|
||||
// This creates a RunArtifact step in the build graph. A RunArtifact step
|
||||
// invokes an executable compiled by Zig. Steps will only be executed by the
|
||||
// runner if invoked directly by the user (in the case of top level steps)
|
||||
// or if another step depends on it, so it's up to you to define when and
|
||||
// how this Run step will be executed. In our case we want to run it when
|
||||
// the user runs `zig build run`, so we create a dependency link.
|
||||
const run_cmd = b.addRunArtifact(exe);
|
||||
run_step.dependOn(&run_cmd.step);
|
||||
|
||||
// By making the run step depend on the default step, it will be run from the
|
||||
// installation directory rather than directly from within the cache directory.
|
||||
run_cmd.step.dependOn(b.getInstallStep());
|
||||
|
||||
// This allows the user to pass arguments to the application in the build
|
||||
// command itself, like this: `zig build run -- arg1 arg2 etc`
|
||||
if (b.args) |args| {
|
||||
run_cmd.addArgs(args);
|
||||
}
|
||||
|
||||
// Creates an executable that will run `test` blocks from the provided module.
|
||||
// Here `mod` needs to define a target, which is why earlier we made sure to
|
||||
// set the releative field.
|
||||
const mod_tests = b.addTest(.{
|
||||
.root_module = mod,
|
||||
});
|
||||
|
||||
// A run step that will run the test executable.
|
||||
const run_mod_tests = b.addRunArtifact(mod_tests);
|
||||
|
||||
// Creates an executable that will run `test` blocks from the executable's
|
||||
// root module. Note that test executables only test one module at a time,
|
||||
// hence why we have to create two separate ones.
|
||||
const exe_tests = b.addTest(.{
|
||||
.root_module = exe.root_module,
|
||||
});
|
||||
|
||||
// A run step that will run the second test executable.
|
||||
const run_exe_tests = b.addRunArtifact(exe_tests);
|
||||
|
||||
// A top level step for running all tests. dependOn can be called multiple
|
||||
// times and since the two run steps do not depend on one another, this will
|
||||
// make the two of them run in parallel.
|
||||
const test_step = b.step("test", "Run tests");
|
||||
test_step.dependOn(&run_mod_tests.step);
|
||||
test_step.dependOn(&run_exe_tests.step);
|
||||
|
||||
// Just like flags, top level steps are also listed in the `--help` menu.
|
||||
//
|
||||
// The Zig build system is entirely implemented in userland, which means
|
||||
// that it cannot hook into private compiler APIs. All compilation work
|
||||
// orchestrated by the build system will result in other Zig compiler
|
||||
// subcommands being invoked with the right flags defined. You can observe
|
||||
// these invocations when one fails (or you pass a flag to increase
|
||||
// verbosity) to validate assumptions and diagnose problems.
|
||||
//
|
||||
// Lastly, the Zig build system is relatively simple and self-contained,
|
||||
// and reading its source code will allow you to master it.
|
||||
}
|
||||
@@ -0,0 +1,81 @@
|
||||
.{
|
||||
// This is the default name used by packages depending on this one. For
|
||||
// example, when a user runs `zig fetch --save <url>`, this field is used
|
||||
// as the key in the `dependencies` table. Although the user can choose a
|
||||
// different name, most users will stick with this provided value.
|
||||
//
|
||||
// It is redundant to include "zig" in this name because it is already
|
||||
// within the Zig package namespace.
|
||||
.name = .rom_dump,
|
||||
// This is a [Semantic Version](https://semver.org/).
|
||||
// In a future version of Zig it will be used for package deduplication.
|
||||
.version = "0.0.0",
|
||||
// Together with name, this represents a globally unique package
|
||||
// identifier. This field is generated by the Zig toolchain when the
|
||||
// package is first created, and then *never changes*. This allows
|
||||
// unambiguous detection of one package being an updated version of
|
||||
// another.
|
||||
//
|
||||
// When forking a Zig project, this id should be regenerated (delete the
|
||||
// field and run `zig build`) if the upstream project is still maintained.
|
||||
// Otherwise, the fork is *hostile*, attempting to take control over the
|
||||
// original project's identity. Thus it is recommended to leave the comment
|
||||
// on the following line intact, so that it shows up in code reviews that
|
||||
// modify the field.
|
||||
.fingerprint = 0x9ea89f2f1f5395c9, // Changing this has security and trust implications.
|
||||
// Tracks the earliest Zig version that the package considers to be a
|
||||
// supported use case.
|
||||
.minimum_zig_version = "0.16.0",
|
||||
// This field is optional.
|
||||
// Each dependency must either provide a `url` and `hash`, or a `path`.
|
||||
// `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
|
||||
// Once all dependencies are fetched, `zig build` no longer requires
|
||||
// internet connectivity.
|
||||
.dependencies = .{
|
||||
// See `zig fetch --save <url>` for a command-line interface for adding dependencies.
|
||||
//.example = .{
|
||||
// // When updating this field to a new URL, be sure to delete the corresponding
|
||||
// // `hash`, otherwise you are communicating that you expect to find the old hash at
|
||||
// // the new URL. If the contents of a URL change this will result in a hash mismatch
|
||||
// // which will prevent zig from using it.
|
||||
// .url = "https://example.com/foo.tar.gz",
|
||||
//
|
||||
// // This is computed from the file contents of the directory of files that is
|
||||
// // obtained after fetching `url` and applying the inclusion rules given by
|
||||
// // `paths`.
|
||||
// //
|
||||
// // This field is the source of truth; packages do not come from a `url`; they
|
||||
// // come from a `hash`. `url` is just one of many possible mirrors for how to
|
||||
// // obtain a package matching this `hash`.
|
||||
// //
|
||||
// // Uses the [multihash](https://multiformats.io/multihash/) format.
|
||||
// .hash = "...",
|
||||
//
|
||||
// // When this is provided, the package is found in a directory relative to the
|
||||
// // build root. In this case the package's hash is irrelevant and therefore not
|
||||
// // computed. This field and `url` are mutually exclusive.
|
||||
// .path = "foo",
|
||||
//
|
||||
// // When this is set to `true`, a package is declared to be lazily
|
||||
// // fetched. This makes the dependency only get fetched if it is
|
||||
// // actually used.
|
||||
// .lazy = false,
|
||||
//},
|
||||
},
|
||||
// Specifies the set of files and directories that are included in this package.
|
||||
// Only files and directories listed here are included in the `hash` that
|
||||
// is computed for this package. Only files listed here will remain on disk
|
||||
// when using the zig package manager. As a rule of thumb, one should list
|
||||
// files required for compilation plus any license(s).
|
||||
// Paths are relative to the build root. Use the empty string (`""`) to refer to
|
||||
// the build root itself.
|
||||
// A directory listed here means that all files within, recursively, are included.
|
||||
.paths = .{
|
||||
"build.zig",
|
||||
"build.zig.zon",
|
||||
"src",
|
||||
// For example...
|
||||
//"LICENSE",
|
||||
//"README.md",
|
||||
},
|
||||
}
|
||||
@@ -0,0 +1,3 @@
|
||||
const Reader = std.Io.Reader;
|
||||
|
||||
//
|
||||
@@ -0,0 +1,38 @@
|
||||
const std = @import("std");
|
||||
const Io = std.Io;
|
||||
|
||||
const snes = @import("snes/root.zig");
|
||||
const Rom = snes.rom.Rom;
|
||||
|
||||
pub fn main(init: std.process.Init) !void {
|
||||
var args = init.minimal.args.iterate();
|
||||
_ = args.skip();
|
||||
|
||||
while (args.next()) |arg| {
|
||||
var file = try std.Io.Dir.cwd().openFile(init.io, arg, .{});
|
||||
defer file.close(init.io);
|
||||
|
||||
var buf: [512]u8 = undefined;
|
||||
var reader = file.reader(init.io, &buf);
|
||||
|
||||
const rom = try Rom.parse(&reader);
|
||||
const header = rom.header();
|
||||
|
||||
std.debug.print(
|
||||
"Parsing {s}\n\ttitle: {s}\n\tmode: {d},\n\tchipset: {d}\n\tromSize: {B}\n\tramSize: {B}\n\tcountryCode: {d}\n\tdeveloperID: {d}\n\tromVersion: {d}\n\tchecksum:\n\t\tcomplement: {d}\n\t\tsum: {d}\n",
|
||||
.{
|
||||
arg,
|
||||
header.title,
|
||||
header.mode,
|
||||
header.chipset,
|
||||
header.romSize.size(),
|
||||
header.ramSize.size(),
|
||||
header.countryCode,
|
||||
header.developerID,
|
||||
header.romVersion,
|
||||
header.checksum.complement,
|
||||
header.checksum.sum,
|
||||
},
|
||||
);
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,4 @@
|
||||
//! By convention, root.zig is the root source file when making a package.
|
||||
const std = @import("std");
|
||||
|
||||
pub const cartridge = @import("cartridge.zig");
|
||||
@@ -0,0 +1,3 @@
|
||||
pub const Error = error{
|
||||
InvalidChecksum,
|
||||
};
|
||||
@@ -0,0 +1,20 @@
|
||||
const std = @import("std");
|
||||
const rom = @import("root.zig");
|
||||
|
||||
const Header = rom.Header;
|
||||
const FileReader = std.Io.File.Reader;
|
||||
|
||||
pub const ExHiROM = struct {
|
||||
header: Header,
|
||||
romFile: *FileReader,
|
||||
|
||||
pub const HeaderLocation = 0x40FFC0;
|
||||
|
||||
// init create things
|
||||
pub fn init(header: Header, romFile: *FileReader) @This() {
|
||||
return .{
|
||||
.header = header,
|
||||
.romFile = romFile,
|
||||
};
|
||||
}
|
||||
};
|
||||
@@ -0,0 +1,50 @@
|
||||
const std = @import("std");
|
||||
const rom = @import("root.zig");
|
||||
|
||||
const Reader = std.Io.Reader;
|
||||
const Error = rom.Error;
|
||||
const Mode = rom.Mode;
|
||||
|
||||
pub const Header = extern struct {
|
||||
title: [21]u8,
|
||||
mode: Mode,
|
||||
chipset: u8,
|
||||
romSize: Bytes,
|
||||
ramSize: Bytes,
|
||||
countryCode: u8,
|
||||
developerID: u8,
|
||||
romVersion: u8,
|
||||
checksum: Checksum,
|
||||
interupts: [32]u8,
|
||||
|
||||
pub const Bytes = extern struct {
|
||||
_shift: u8,
|
||||
|
||||
pub fn size(self: @This()) usize {
|
||||
return (@as(usize, 1) <<| self._shift) * 1024;
|
||||
}
|
||||
};
|
||||
|
||||
pub const Checksum = extern struct {
|
||||
complement: u16,
|
||||
sum: u16,
|
||||
|
||||
pub fn valid(self: @This()) bool {
|
||||
return self.sum +% self.complement +% 1 != 0;
|
||||
}
|
||||
};
|
||||
|
||||
/// parse assumes the reader is at the beggining of the rom, and
|
||||
/// therefore skips any data in the copier section if there is one.
|
||||
pub fn parse(from: *Reader) !@This() {
|
||||
var data: [@sizeOf(@This())]u8 = undefined;
|
||||
try from.readSliceAll(&data);
|
||||
const header: @This() = @bitCast(data);
|
||||
|
||||
if (header.checksum.valid()) {
|
||||
return Error.InvalidChecksum;
|
||||
}
|
||||
|
||||
return header;
|
||||
}
|
||||
};
|
||||
@@ -0,0 +1,21 @@
|
||||
const std = @import("std");
|
||||
const rom = @import("root.zig");
|
||||
|
||||
const Header = rom.Header;
|
||||
const FileReader = std.Io.File.Reader;
|
||||
|
||||
pub const HiROM = struct {
|
||||
header: Header,
|
||||
romFile: *FileReader,
|
||||
|
||||
// The Location of the header in this rom type
|
||||
pub const HeaderLocation = 0x00FFC0;
|
||||
|
||||
// init create things
|
||||
pub fn init(header: Header, romFile: *FileReader) @This() {
|
||||
return .{
|
||||
.header = header,
|
||||
.romFile = romFile,
|
||||
};
|
||||
}
|
||||
};
|
||||
@@ -0,0 +1,21 @@
|
||||
const std = @import("std");
|
||||
const rom = @import("root.zig");
|
||||
|
||||
const Header = rom.Header;
|
||||
const FileReader = std.Io.File.Reader;
|
||||
|
||||
pub const LoROM = struct {
|
||||
header: Header,
|
||||
romFile: *FileReader,
|
||||
|
||||
// The location of the header in this rom mode
|
||||
pub const HeaderLocation = 0x007FC0;
|
||||
|
||||
// init create things
|
||||
pub fn init(header: Header, romFile: *FileReader) @This() {
|
||||
return .{
|
||||
.header = header,
|
||||
.romFile = romFile,
|
||||
};
|
||||
}
|
||||
};
|
||||
@@ -0,0 +1,12 @@
|
||||
// Ignoring the optional 512-byte header, the files contain the contents of the cartridge ROM in linear order. Depending on how the cartridge is mapped, there are 3 orderings:
|
||||
//
|
||||
// LoROM: 32k banks starting from $800000
|
||||
// HiROM: 64k banks starting from $C00000
|
||||
// ExHiROM: 64k banks starting from $C00000, then continuing from $400000 after 4MB.
|
||||
//
|
||||
// This means that the ROM header could be at one of 3 locations which maps to memory at $00FFC0:
|
||||
pub const Mode = enum(u8) {
|
||||
LoROM = 0,
|
||||
HiROM = 1,
|
||||
ExHiROM = 5,
|
||||
};
|
||||
@@ -0,0 +1,91 @@
|
||||
const std = @import("std");
|
||||
const rom = @import("root.zig");
|
||||
|
||||
const FileReader = std.Io.File.Reader;
|
||||
const Reader = std.Io.Reader;
|
||||
|
||||
const Error = rom.Error;
|
||||
const ExHiROM = rom.ExHiROM;
|
||||
const Header = rom.Header;
|
||||
const HiROM = rom.HiROM;
|
||||
const LoROM = rom.LoROM;
|
||||
const Mode = rom.Mode;
|
||||
|
||||
pub const Rom = union(Mode) {
|
||||
// TODO: you need to make this into a struct and the memory layout a field
|
||||
// since you should store the header in here and if the data was headered or
|
||||
// unheadered
|
||||
LoROM: LoROM,
|
||||
HiROM: HiROM,
|
||||
ExHiROM: ExHiROM,
|
||||
|
||||
/// parse takes a rom file (seeked to 0) and parses it into a ROM
|
||||
/// if the file is not a valid ROM file it will return Error.InvalidChecksum
|
||||
pub fn parse(romFile: *FileReader) !Rom {
|
||||
// The data contained in the file may be unheadered or headered. The only difference
|
||||
// between these two is that the headered version has 512 extra bytes at the start of the file.
|
||||
//
|
||||
// The 512 byte header is not the same as the ROM header, which is a part of the on-cartridge
|
||||
// ROM. Instead it is 512 bytes of metadata gathered by a Copier device used to dump the ROM.
|
||||
// This extra data is generally considered useless, except to the specific copier device that
|
||||
// it was originally used with. Modern common practice prefers unheadered ROM files.
|
||||
inline for ([_]usize{ 0, 512 }) |offset| {
|
||||
// Now lets loop through each of the different memory types
|
||||
// Ignoring the optional 512-byte header, the files contain the contents of the cartridge
|
||||
// ROM in linear order. Depending on how the cartridge is mapped, there are 3 orderings:
|
||||
// LoROM: 32k banks starting from $800000
|
||||
// HiROM: 64k banks starting from $C00000
|
||||
// ExHiROM: 64k banks starting from $C00000, then continuing from $400000 after 4MB.
|
||||
//
|
||||
// This means that the ROM header could be at one of 3 locations which maps to memory at $00FFC0:
|
||||
//
|
||||
// LoROM: $007FC0
|
||||
// HiROM: $00FFC0
|
||||
// ExHiROM: $40FFC0
|
||||
inline for (std.meta.fields(@This())) |field| {
|
||||
try romFile.seekTo(field.type.HeaderLocation + offset);
|
||||
const maybe_header = Header.parse(&romFile.interface) catch null;
|
||||
|
||||
if (maybe_header) |head| {
|
||||
return @unionInit(@This(), field.name, field.type.init(head, romFile));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return Error.InvalidChecksum;
|
||||
}
|
||||
|
||||
/// header will return the header of the ROM file
|
||||
pub fn header(self: *const @This()) *const Header {
|
||||
switch (self.*) {
|
||||
.LoROM => |*loRom| return &loRom.header,
|
||||
.HiROM => |*hiRom| return &hiRom.header,
|
||||
.ExHiROM => |*exHiRom| return &exHiRom.header,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn checksum(self: *const @This(), romReader: *Reader) !u16 {
|
||||
var head = self.header().*;
|
||||
head.checksum.complement = 0xFFFF;
|
||||
head.checksum.sum = 0x0000;
|
||||
|
||||
var sum: u16 = 0;
|
||||
const headerBytes: [@sizeOf(@TypeOf(header))]u8 = @bitCast(header);
|
||||
for (headerBytes) |b| {
|
||||
sum +%= @as(u16, b);
|
||||
}
|
||||
|
||||
const header_location = switch (self.*) {
|
||||
.LoROM => |*rom| rom.HeaderLocation,
|
||||
.HiROM => |*rom| rom.HeaderLocation,
|
||||
.ExHiROM => |*rom| rom.HeaderLocation,
|
||||
};
|
||||
|
||||
for (@sizeOf(@TypeOf(header))..header.romSize.size()) |_| {
|
||||
const b = try romReader.takeByte();
|
||||
sum +%= @intCast(b);
|
||||
}
|
||||
|
||||
return sum;
|
||||
}
|
||||
};
|
||||
@@ -0,0 +1,7 @@
|
||||
pub const Error = @import("error.zig").Error;
|
||||
pub const ExHiROM = @import("ex_hi_rom.zig").ExHiROM;
|
||||
pub const Header = @import("header.zig").Header;
|
||||
pub const HiROM = @import("hi_rom.zig").HiROM;
|
||||
pub const LoROM = @import("lo_rom.zig").LoROM;
|
||||
pub const Mode = @import("mode.zig").Mode;
|
||||
pub const Rom = @import("rom.zig").Rom;
|
||||
@@ -0,0 +1 @@
|
||||
pub const rom = @import("rom/root.zig");
|
||||
Reference in New Issue
Block a user