chore: update to lastest zig

while I figure out the interface with zba, disable the exe example
since it doesn't have an emu to pass to gdbstub

build.zig

@@ -27,6 +27,7 @@ pub fn link(exe: *std.build.LibExeObjStep) void {
 
 pub fn build(b: *std.build.Builder) void {
     const target = b.standardTargetOptions(.{});
+    _ = target;
     const mode = b.standardReleaseOptions();
 
     // -- library --
@@ -42,18 +43,18 @@ pub fn build(b: *std.build.Builder) void {
     const test_step = b.step("lib-test", "Run Library Tests");
     test_step.dependOn(&lib_tests.step);
 
-    // -- Executable --
-    const exe = b.addExecutable("gdbserver", "src/main.zig");
-    link(exe);
+    // // -- Executable --
+    // const exe = b.addExecutable("gdbserver", "src/main.zig");
+    // link(exe);
 
-    exe.setTarget(target);
-    exe.setBuildMode(mode);
-    exe.install();
+    // exe.setTarget(target);
+    // exe.setBuildMode(mode);
+    // exe.install();
 
-    const run_cmd = exe.run();
-    run_cmd.step.dependOn(b.getInstallStep());
-    if (b.args) |args| run_cmd.addArgs(args);
+    // const run_cmd = exe.run();
+    // run_cmd.step.dependOn(b.getInstallStep());
+    // if (b.args) |args| run_cmd.addArgs(args);
 
-    const run_step = b.step("run", "Run the app");
-    run_step.dependOn(&run_cmd.step);
+    // const run_step = b.step("run", "Run the app");
+    // run_step.dependOn(&run_cmd.step);
 }

src/Packet.zig

@@ -1,7 +1,10 @@
 const std = @import("std");
 
-const target = @import("Server.zig").target;
 const Allocator = std.mem.Allocator;
+const Emulator = @import("lib.zig").Emulator;
+
+const target = @import("Server.zig").target;
+const memory_map = @import("Server.zig").memory_map;
 
 const Self = @This();
 const log = std.log.scoped(.Packet);
@@ -16,8 +19,6 @@ pub fn from(allocator: Allocator, str: []const u8) !Self {
     const chksum_str = tokens.next() orelse return error.MissingCheckSum;
     const chksum = std.fmt.parseInt(u8, chksum_str, 16) catch return error.InvalidChecksum;
 
-    // log.info("Contents: {s}", .{contents});
-
     if (!Self.verify(contents, chksum)) return error.ChecksumMismatch;
 
     return .{ .contents = try allocator.dupe(u8, contents) };
@@ -44,34 +45,29 @@ const String = union(enum) {
     }
 };
 
-pub fn parse(self: *Self, allocator: Allocator) !String {
+pub fn parse(self: *Self, allocator: Allocator, emu: Emulator) !String {
     switch (self.contents[0]) {
         // Required
         '?' => {
-            const ret: Signal = .Trap;
-
-            // Deallocated by the caller
-            return .{ .alloc = try std.fmt.allocPrint(allocator, "T{x:0>2}thread:1;", .{@enumToInt(ret)}) };
+            const ret = try std.fmt.allocPrint(allocator, "S{x:0>2}", .{@enumToInt(Signal.Int)});
+            return .{ .alloc = ret };
         },
         'g' => {
-            // TODO: Actually reference GBA Registers
-            const r = [_]u32{0xDEAD_BEEF} ** 0x10;
-            const cpsr: u32 = 0xCAFE_B0BA;
-
-            const char_len = 2;
-            const reg_len = @sizeOf(u32) * char_len; // Every byte is represented by 2 characters
+            const r = emu.registers();
+            const cpsr = emu.cpsr();
 
+            const reg_len = @sizeOf(u32) * 2; // Every byte is represented by 2 characters
             const ret = try allocator.alloc(u8, r.len * reg_len + reg_len); // r0 -> r15 + CPSR
 
             {
-                var i: usize = 0;
+                var i: u32 = 0;
                 while (i < r.len + 1) : (i += 1) {
-                    const reg: u32 = if (i < r.len) r[i] else cpsr;
+                    var reg: u32 = if (i < r.len) r[i] else cpsr;
+                    if (i == 15) reg -= if (cpsr >> 5 & 1 == 1) 4 else 8; // PC is ahead
 
-                    // bufPrintIntToSlice writes to the provided slice, which is all we want from this
-                    // consequentially, we ignore the slice it returns since it just references the slice
-                    // passed as an argument
-                    _ = std.fmt.bufPrintIntToSlice(ret[i * 8 ..][0..8], reg, 16, .lower, .{ .fill = '0', .width = 8 });
+                    // writes the formatted integer to the buffer, returns a slice to the buffer but we ignore that
+                    // GDB also expects the bytes to be in the opposite order for whatever reason
+                    _ = std.fmt.bufPrintIntToSlice(ret[i * 8 ..][0..8], @byteSwap(reg), 16, .lower, .{ .fill = '0', .width = 8 });
                 }
             }
 
@@ -79,25 +75,23 @@ pub fn parse(self: *Self, allocator: Allocator) !String {
         },
         'G' => @panic("TODO: Register Write"),
         'm' => {
-            // TODO: Actually reference GBA Memory
-            log.err("{s}", .{self.contents});
-
             var tokens = std.mem.tokenize(u8, self.contents[1..], ",");
             const addr_str = tokens.next() orelse return .{ .static = "E9999" }; // EUNKNOWN
             const length_str = tokens.next() orelse return .{ .static = "E9999" }; // EUNKNOWN
 
             const addr = try std.fmt.parseInt(u32, addr_str, 16);
             const len = try std.fmt.parseInt(u32, length_str, 16);
-            _ = addr;
 
             const ret = try allocator.alloc(u8, len * 2);
 
             {
-                var i: usize = 0;
+                var i: u32 = 0;
                 while (i < len) : (i += 1) {
-                    const value: u8 = 0;
+                    const value = emu.read(addr + i);
+                    log.debug("read 0x{X:0>2} from 0x{X:0>8}", .{ value, addr + i });
 
-                    _ = std.fmt.bufPrintIntToSlice(ret[i * 2 ..][0..2], value, 16, .lower, .{ .fill = '0', .width = 2 });
+                    // writes the formatted integer to the buffer, returns a slice to the buffer but we ignore that
+                    _ = std.fmt.bufPrintIntToSlice(ret[i * 2 ..][0..2], emu.read(addr + i), 16, .lower, .{ .fill = '0', .width = 2 });
                 }
             }
 
@@ -105,20 +99,22 @@ pub fn parse(self: *Self, allocator: Allocator) !String {
         },
         'M' => @panic("TODO: Memory Write"),
         'c' => @panic("TODO: Continue"),
-        's' => @panic("TODO: Step"),
+        's' => {
+            // var tokens = std.mem.tokenize(u8, self.contents[1..], " ");
+            // const addr = if (tokens.next()) |s| try std.fmt.parseInt(u32, s, 16) else null;
+
+            emu.step();
+
+            const ret = try std.fmt.allocPrint(allocator, "S{x:0>2}", .{@enumToInt(Signal.Trap)});
+            return .{ .alloc = ret };
+        },
 
         // Optional
-        'H' => {
-            log.warn("{s}", .{self.contents});
-
-            switch (self.contents[1]) {
-                'g', 'c' => return .{ .static = "OK" },
-                else => {
-                    log.warn("Unimplemented: {s}", .{self.contents});
-                    return .{ .static = "" };
-                },
-            }
+        'D' => {
+            log.info("Disconnecting...", .{});
+            return .{ .static = "OK" };
         },
+        'H' => return .{ .static = "" },
         'v' => {
             if (substr(self.contents[1..], "MustReplyEmpty")) {
                 return .{ .static = "" };
@@ -143,16 +139,14 @@ pub fn parse(self: *Self, allocator: Allocator) !String {
 
             if (substr(self.contents[1..], "Xfer:features:read")) {
                 var tokens = std.mem.tokenize(u8, self.contents[1..], ":,");
-                _ = tokens.next(); // qXfer
+                _ = tokens.next(); // Xfer
                 _ = tokens.next(); // features
                 _ = tokens.next(); // read
-                const annex = tokens.next() orelse return .{ .static = "E00" };
-                const offset_str = tokens.next() orelse return .{ .static = "E00" };
-                const length_str = tokens.next() orelse return .{ .static = "E00" };
+                const annex = tokens.next() orelse return .{ .static = "E9999" };
+                const offset_str = tokens.next() orelse return .{ .static = "E99999" };
+                const length_str = tokens.next() orelse return .{ .static = "E9999" };
 
                 if (std.mem.eql(u8, annex, "target.xml")) {
-                    log.info("Providing ARMv4T target description", .{});
-
                     const offset = try std.fmt.parseInt(usize, offset_str, 16);
                     const length = try std.fmt.parseInt(usize, length_str, 16);
 
@@ -168,12 +162,33 @@ pub fn parse(self: *Self, allocator: Allocator) !String {
                     return .{ .alloc = ret };
                 } else {
                     log.err("Unexpected Annex: {s}", .{annex});
-                    return .{ .static = "E00" };
+                    return .{ .static = "E9999" };
                 }
 
                 return .{ .static = "" };
             }
 
+            if (substr(self.contents[1..], "Xfer:memory-map:read")) {
+                var tokens = std.mem.tokenize(u8, self.contents[1..], ":,");
+                _ = tokens.next(); // Xfer
+                _ = tokens.next(); // memory-map
+                _ = tokens.next(); // read
+                const offset_str = tokens.next() orelse return .{ .static = "E9999" };
+                const length_str = tokens.next() orelse return .{ .static = "E9999" };
+
+                const offset = try std.fmt.parseInt(usize, offset_str, 16);
+                const length = try std.fmt.parseInt(usize, length_str, 16);
+
+                // see above
+                const len = @min(length, (memory_map.len + 1) - offset);
+                const ret = try allocator.alloc(u8, len);
+
+                ret[0] = if (ret.len < length) 'l' else 'm';
+                std.mem.copy(u8, ret[1..], memory_map[offset..]);
+
+                return .{ .alloc = ret };
+            }
+
             log.warn("Unimplemented: {s}", .{self.contents});
             return .{ .static = "" };
         },
@@ -206,7 +221,7 @@ fn verify(input: []const u8, chksum: u8) bool {
 }
 
 const Signal = enum(u32) {
-    Hup, // Hangup
+    Hup = 1, // Hangup
     Int, // Interrupt
     Quit, // Quit
     Ill, // Illegal Instruction

src/Server.zig

@@ -4,6 +4,7 @@ const Packet = @import("Packet.zig");
 
 const Socket = network.Socket;
 const Allocator = std.mem.Allocator;
+const Emulator = @import("lib.zig").Emulator;
 
 const Self = @This();
 const log = std.log.scoped(.Server);
@@ -35,13 +36,32 @@ pub const target: []const u8 =
     \\</target>
 ;
 
+// Game Pak SRAM isn't included
+// TODO: Can i be more specific here?
+pub const memory_map: []const u8 =
+    \\ <memory-map version="1.0">
+    \\     <memory type="rom" start="0x00000000" length="0x00004000"/>
+    \\     <memory type="ram" start="0x02000000" length="0x00040000"/>
+    \\     <memory type="ram" start="0x03000000" length="0x00008000"/>
+    \\     <memory type="ram" start="0x04000000" length="0x00000400"/>
+    \\     <memory type="ram" start="0x05000000" length="0x00000400"/>
+    \\     <memory type="ram" start="0x06000000" length="0x00018000"/>
+    \\     <memory type="ram" start="0x07000000" length="0x00000400"/>
+    \\     <memory type="rom" start="0x08000000" length="0x02000000"/>
+    \\     <memory type="rom" start="0x0A000000" length="0x02000000"/>
+    \\     <memory type="rom" start="0x0C000000" length="0x02000000"/>
+    \\ </memory-map>
+;
+
 // FIXME: Shouldn't this be a Packet Struct?
 pkt_cache: ?[]const u8 = null,
 
 client: Socket,
 _socket: Socket,
 
-pub fn init() !Self {
+emu: Emulator,
+
+pub fn init(emulator: Emulator) !Self {
     try network.init();
 
     var socket = try Socket.create(.ipv4, .tcp);
@@ -53,7 +73,7 @@ pub fn init() !Self {
     const endpoint = try client.getLocalEndPoint();
     log.info("client connected from {}", .{endpoint});
 
-    return .{ ._socket = socket, .client = client };
+    return .{ .emu = emulator, ._socket = socket, .client = client };
 }
 
 pub fn deinit(self: *Self, allocator: Allocator) void {
@@ -81,39 +101,50 @@ pub fn run(self: *Self, allocator: Allocator) !void {
         const len = try self.client.receive(&buf);
         if (len == 0) break;
 
-        const action = try Self.parse(allocator, buf[0..len]);
+        const action = try self.parse(allocator, buf[0..len]);
         try self.send(allocator, action);
     }
 }
 
-fn parse(allocator: Allocator, input: []const u8) !Action {
+fn parse(self: *Self, allocator: Allocator, input: []const u8) !Action {
+    // log.debug("-> {s}", .{input});
+
     return switch (input[0]) {
-        '+' => .nothing,
-        '-' => .retry,
-        '$' => blk: {
-            // Packet
-            var packet = Packet.from(allocator, input) catch return .nack;
-            defer packet.deinit(allocator);
+        '+' => blk: {
+            if (input.len == 1) break :blk .nothing;
 
-            var string = packet.parse(allocator) catch return .nack;
-            defer string.deinit(allocator);
-
-            const reply = string.inner();
-
-            // deallocated by the caller
-            const response = try std.fmt.allocPrint(allocator, "${s}#{x:0>2}", .{ reply, Packet.checksum(reply) });
-
-            break :blk .{ .send = response };
+            break :blk switch (input[1]) {
+                '$' => self.handlePacket(allocator, input[1..]),
+                else => std.debug.panic("Unknown: {s}", .{input}),
+            };
         },
+        '-' => .retry,
+        '$' => try self.handlePacket(allocator, input),
+        '\x03' => .nothing,
         else => std.debug.panic("Unknown: {s}", .{input}),
     };
 }
 
+fn handlePacket(self: *Self, allocator: Allocator, input: []const u8) !Action {
+    var packet = Packet.from(allocator, input) catch return .nack;
+    defer packet.deinit(allocator);
+
+    var string = packet.parse(allocator, self.emu) catch return .nack;
+    defer string.deinit(allocator);
+
+    const reply = string.inner();
+
+    // deallocated by the caller
+    const response = try std.fmt.allocPrint(allocator, "+${s}#{x:0>2}", .{ reply, Packet.checksum(reply) });
+
+    return .{ .send = response };
+}
+
 fn send(self: *Self, allocator: Allocator, action: Action) !void {
     switch (action) {
         .send => |pkt| {
-            _ = try self.client.send("+"); // ACK
             _ = try self.client.send(pkt);
+            // log.debug("<- {s}", .{pkt});
 
             self.reset(allocator);
             self.pkt_cache = pkt;
@@ -121,14 +152,21 @@ fn send(self: *Self, allocator: Allocator, action: Action) !void {
         .retry => {
             log.warn("received nack, resending: \"{?s}\"", .{self.pkt_cache});
 
-            if (self.pkt_cache) |pkt| _ = try self.client.send(pkt); // FIXME: is an ack to a nack necessary?
+            if (self.pkt_cache) |pkt| {
+                _ = try self.client.send(pkt);
+                // log.debug("<- {s}", .{pkt});
+            }
         },
         .ack => {
             _ = try self.client.send("+");
+            // log.debug("<- +", .{});
+
             self.reset(allocator);
         },
         .nack => {
             _ = try self.client.send("-");
+            // log.debug("<- -", .{});
+
             self.reset(allocator);
         },
         .nothing => self.reset(allocator),

src/lib.zig

@@ -10,9 +10,10 @@ pub const Emulator = struct {
     readFn: *const fn (*anyopaque, u32) u8,
     writeFn: *const fn (*anyopaque, u32, u8) void,
 
-    // FIXME: Expensive copy
-    registersFn: *const fn (*const anyopaque) [16]u32,
-    cpsrFn: *const fn (*const anyopaque) u32,
+    registersFn: *const fn (*anyopaque) *[16]u32,
+    cpsrFn: *const fn (*anyopaque) u32,
+
+    stepFn: *const fn (*anyopaque) void,
 
     pub fn init(ptr: anytype) Self {
         const Ptr = @TypeOf(ptr);
@@ -27,35 +28,35 @@ pub const Emulator = struct {
             pub fn readImpl(pointer: *anyopaque, addr: u32) u8 {
                 const self = @ptrCast(Ptr, @alignCast(alignment, pointer));
 
-                return @call(.{ .modifier = .always_inline }, ptr_info.Pointer.child.read, .{ u8, self, addr });
+                return @call(.always_inline, ptr_info.Pointer.child.read, .{ self, addr });
             }
 
             pub fn writeImpl(pointer: *anyopaque, addr: u32, value: u8) void {
                 const self = @ptrCast(Ptr, @alignCast(alignment, pointer));
 
-                return @call(.{ .modifier = .always_inline }, ptr_info.Pointer.child.read, .{ u8, self, addr, value });
+                return @call(.always_inline, ptr_info.Pointer.child.write, .{ self, addr, value });
             }
 
-            pub fn registersImpl(pointer: *const anyopaque) [16]u32 {
+            pub fn registersImpl(pointer: *anyopaque) *[16]u32 {
                 const self = @ptrCast(Ptr, @alignCast(alignment, pointer));
 
-                return self.r;
+                return @call(.always_inline, ptr_info.Pointer.child.registers, .{self});
             }
 
-            pub fn cpsrImpl(pointer: *const anyopaque) u32 {
+            pub fn cpsrImpl(pointer: *anyopaque) u32 {
                 const self = @ptrCast(Ptr, @alignCast(alignment, pointer));
 
-                return self.cpsr.raw;
+                return @call(.always_inline, ptr_info.Pointer.child.cpsr, .{self});
+            }
+
+            pub fn stepImpl(pointer: *anyopaque) void {
+                const self = @ptrCast(Ptr, @alignCast(alignment, pointer));
+
+                return @call(.always_inline, ptr_info.Pointer.child.step, .{self});
             }
         };
 
-        return .{
-            .ptr = ptr,
-            .readFn = gen.readImpl,
-            .writeFn = gen.writeImpl,
-            .registersFn = gen.registersImpl,
-            .cpsrFn = gen.cpsrImpl,
-        };
+        return .{ .ptr = ptr, .readFn = gen.readImpl, .writeFn = gen.writeImpl, .registersFn = gen.registersImpl, .cpsrFn = gen.cpsrImpl, .stepFn = gen.stepImpl };
     }
 
     pub inline fn read(self: Self, addr: u32) u8 {
@@ -66,11 +67,15 @@ pub const Emulator = struct {
         self.writeFn(self.ptr, addr, value);
     }
 
-    pub inline fn registers(self: Self) [16]u32 {
+    pub inline fn registers(self: Self) *[16]u32 {
         return self.registersFn(self.ptr);
     }
 
     pub inline fn cpsr(self: Self) u32 {
         return self.cpsrFn(self.ptr);
     }
+
+    pub inline fn step(self: Self) void {
+        self.stepFn(self.ptr);
+    }
 };