[MODS/WASM]: Get tables, elems, data and more VM instructions working

modding/log.zig

@@ -1,19 +1,19 @@
 pub extern fn logErr(
-    format: [*:0]const u8,
+    string: *const u8,
-    ...,
+    len: u64,
 ) void;
 
 pub extern fn logWarn(
-    format: [*:0]const u8,
+    string: *const u8,
-    ...,
+    len: u64,
 ) void;
 
 pub extern fn logInfo(
-    format: [*:0]const u8,
+    string: *const u8,
-    ...,
+    len: u64,
 ) void;
 
 pub extern fn logDebug(
-    format: [*:0]const u8,
+    string: *const u8,
-    ...,
+    len: u64,
 ) void;

src/mods/Parser.zig

@@ -14,11 +14,14 @@ exports: vm.Exports,
 importCount: u32,
 exported_memory: u32,
 
+parsedData: []u8,
+tables: []Tabletype,
+elems: [][]u32,
 globalValues: []vm.Value,
 globalTypes: []Globaltype,
 
 const Parser = @This();
-const PAGE_SIZE = 64_000;
+const PAGE_SIZE = 65536;
 
 pub const Error = error{
     OutOfMemory,
@@ -41,12 +44,17 @@ pub const Error = error{
     duplicated_funcsec,
     duplicated_typesec,
     duplicated_globalsec,
+    duplicated_tablesec,
+    duplicated_elemsec,
     unresolved_branch,
     unterminated_wasm,
 };
 
 pub fn init(allocator: Allocator, bytes: []const u8) !Parser {
     return .{
+        .elems = &.{},
+        .tables = &.{},
+        .parsedData = &.{},
         .exported_memory = 0,
         .importCount = 0,
         .bytes = bytes,
@@ -72,12 +80,14 @@ pub fn deinit(self: Parser) void {
         self.allocator.free(t.returns);
     }
     self.allocator.free(self.types);
-    self.allocator.free(self.functions);
 }
 
 pub fn module(self: *Parser) vm.Module {
     defer self.functions = &.{};
     return .{
+        .elems = self.elems,
+        .tables = self.tables,
+        .data = self.parsedData,
         .memory = .{
             .min = self.memory.lim.min,
             .max = self.memory.lim.max,
@@ -165,7 +175,7 @@ fn VectorFnResult(parse_fn: anytype) type {
         else => ret_type,
     };
 }
-fn parseVector(self: *Parser, parse_fn: anytype) ![]VectorFnResult(parse_fn) {
+pub fn parseVector(self: *Parser, parse_fn: anytype) ![]VectorFnResult(parse_fn) {
     const n = try self.readU32();
     const ret = try self.allocator.alloc(VectorFnResult(parse_fn), n);
     for (ret) |*i| {
@@ -231,12 +241,12 @@ const Limits = struct {
 fn parseLimits(self: *Parser) !Limits {
     return switch (try self.readByte()) {
         0x00 => .{
-            .min = try self.readU32() * PAGE_SIZE,
+            .min = try self.readU32(),
             .max = null,
         },
         0x01 => .{
-            .min = try self.readU32() * PAGE_SIZE,
+            .min = try self.readU32(),
-            .max = try self.readU32() * PAGE_SIZE,
+            .max = try self.readU32(),
         },
         else => Error.invalid_limits,
     };
@@ -249,7 +259,7 @@ fn parseMemtype(self: *Parser) !Memtype {
     return .{ .lim = try self.parseLimits() };
 }
 
-const Tabletype = struct {
+pub const Tabletype = struct {
     et: std.wasm.RefType,
     lim: Limits,
 };
@@ -359,7 +369,6 @@ fn parseImportsec(self: *Parser) !void {
     const end_idx = self.byte_idx + size;
 
     const imports = try self.parseVector(Parser.parseImport);
-    self.importCount = @intCast(imports.len);
 
     var index: u32 = 0;
 
@@ -379,9 +388,17 @@ fn parseImportsec(self: *Parser) !void {
                 }
                 index += 1;
             },
+            .mem => {
+                self.memory = i.importdesc.mem;
+                self.memory.lim.min *= PAGE_SIZE;
+                if (self.memory.lim.max != null) {
+                    self.memory.lim.max.? *= PAGE_SIZE;
+                }
+            },
             else => std.debug.print("[TODO]: Handle import desc {any}\n", .{i.importdesc}),
         }
     }
+    self.importCount = index;
     defer self.allocator.free(imports);
 
     // TODO: run this check not only on debug
@@ -414,10 +431,31 @@ fn parseFuncsec(self: *Parser) !void {
     std.debug.assert(self.byte_idx == end_idx);
 }
 
+pub const Table = struct {
+    t: Tabletype,
+};
+
+fn parseTable(self: *Parser) !Table {
+    return .{
+        .t = try self.parseTabletype()
+    };
+}
+
 fn parseTablesec(self: *Parser) !void {
-    self.warn("tablesec");
     const size = try self.readU32();
-    _ = try self.read(size);
+    const end_idx = self.byte_idx + size;
+
+    const tables = try self.parseVector(Parser.parseTable);
+    defer self.allocator.free(tables);
+
+    if (self.tables.len != 0) return Error.duplicated_tablesec;
+    self.tables = try self.allocator.alloc(Tabletype, tables.len);
+
+    for (tables, 0..) |t, i| {
+        self.tables[i] = t.t;
+    }
+ 
+    std.debug.assert(self.byte_idx == end_idx);
 }
 
 fn parseMemsec(self: *Parser) !void {
@@ -430,6 +468,10 @@ fn parseMemsec(self: *Parser) !void {
         // WTF?
     } else if (mems.len == 1) {
         self.memory = mems[0];
+        self.memory.lim.min *= PAGE_SIZE;
+        if (self.memory.lim.max != null) {
+            self.memory.lim.max.? *= PAGE_SIZE;
+        }
     } else {
         std.debug.print("[WARN]: Parsing more than one memory is not yet supported\n", .{});
     }
@@ -526,10 +568,71 @@ fn parseStartsec(self: *Parser) !void {
     _ = try self.read(size);
 }
 
+const Elemmode = union(enum) {
+    Passive,
+    Active: struct {
+        tableidx: u32,
+        offset: vm.Value,
+    },
+    Declarative,
+};
+
+pub const Elem = struct {
+    indices: []u32,
+    elemMode: Elemmode,
+};
+
+fn parseElem(self: *Parser) !Elem {
+    const b: u32 = try self.readU32();
+    switch (b){
+        0 => {
+            // if (try self.parseReftype() != std.wasm.RefType.funcref){
+            //     std.debug.panic("Active function index element table was not a function reference\n", .{});
+            // }
+            const elemMode: Elemmode = .{
+                .Active = .{
+                    .tableidx = 0,
+                    .offset = try vm.handleGlobalInit(self.allocator, try IR.parseGlobalExpr(self)),
+                }
+            };
+            const n = try self.readU32();
+            const indices: []u32 = try self.allocator.alloc(u32, n);
+            for (0..n) |i| {
+                indices[i] = try self.readU32();
+            }
+            return .{
+                .indices = indices,
+                .elemMode = elemMode,
+            };
+        },
+        else => {
+            std.debug.panic("TODO: Handle elem type {any}\n", .{b});
+        }
+    }
+}
+
 fn parseElemsec(self: *Parser) !void {
-    self.warn("elemsec");
     const size = try self.readU32();
-    _ = try self.read(size);
+    const end_idx = self.byte_idx + size;
+
+    const elems = try self.parseVector(Parser.parseElem);
+    defer self.allocator.free(elems);
+
+    self.elems = try self.allocator.alloc([]u32, elems.len);
+
+    for (elems) |elem| {
+        if (elem.elemMode != Elemmode.Active){
+            std.debug.panic("No support for non active elements\n", .{});
+        }
+        const tab = self.tables[elem.elemMode.Active.tableidx];
+        self.elems[elem.elemMode.Active.tableidx] = try self.allocator.alloc(u32, tab.lim.min);
+        std.crypto.secureZero(u32, self.elems[elem.elemMode.Active.tableidx]);
+        for (elem.indices, 0..) |idx, i| {
+            self.elems[elem.elemMode.Active.tableidx][i + @as(usize, @intCast(elem.elemMode.Active.offset.i32))] = idx;
+        }
+    }
+
+    std.debug.assert(self.byte_idx == end_idx);
 }
 
 pub const Func = struct {
@@ -599,10 +702,36 @@ fn parseCodesec(self: *Parser) !void {
     std.debug.assert(self.byte_idx == end_idx);
 }
 
+pub const Data = struct {
+    offsetVal: vm.Value,
+    data: []u8,
+};
+
+fn parseData(self: *Parser) !Data {
+    const b: u32 = try self.readU32();
+    switch (b) {
+        0 => {
+            return .{
+                .offsetVal = try vm.handleGlobalInit(self.allocator, try IR.parseGlobalExpr(self)),
+                .data = try self.parseVector(readByte),
+            };
+        },
+        else => {
+            std.debug.panic("TODO: Handle data type {any}\n", .{b});
+        }
+    }
+}
+
 fn parseDatasec(self: *Parser) !void {
-    self.warn("datasec");
     const size = try self.readU32();
-    _ = try self.read(size);
+    const end_idx = self.byte_idx + size;
+    const datas = try self.parseVector(Parser.parseData);
+    defer self.allocator.free(datas);
+    for (datas) |data| {
+        self.parsedData = try self.allocator.realloc(self.parsedData, @as(usize, @intCast(data.offsetVal.i32)) + data.data.len);
+        @memcpy(self.parsedData[@as(usize, @intCast(data.offsetVal.i32))..@as(usize, @intCast(data.offsetVal.i32))+data.data.len], data.data);
+    }
+    std.debug.assert(self.byte_idx == end_idx);
 }
 
 fn parseDatacountsec(self: *Parser) !void {

src/mods/ir.zig

@@ -628,10 +628,10 @@ const IRParserState = struct {
             0x02...0x03 => self.parseBlock(b),
             0x04 => self.parseIf(),
             0x0C...0x0D => self.parseBranch(b),
-            0x0E => @panic("UNIMPLEMENTED"),
+            0x0E => self.parseTableBranch(b),
             0x0F => self.push(@enumFromInt(b), .{ .u64 = 0 }),
             0x10 => self.push(@enumFromInt(b), .{ .u32 = try self.parser.readU32() }),
-            0x11 => @panic("UNIMPLEMENTED"),
+            0x11 => self.push(@enumFromInt(b), .{ .indirect = .{ .y = try self.parser.readU32(), .x = try self.parser.readU32() } }),
             0xD0 => self.push(@enumFromInt(b), .{ .reftype = try self.parser.parseReftype() }),
             0xD1 => self.push(@enumFromInt(b), .{ .u64 = 0 }),
             0xD2 => self.push(@enumFromInt(b), .{ .u32 = try self.parser.readU32() }),
@@ -683,7 +683,14 @@ const IRParserState = struct {
         const n = try self.parser.readU32();
         try switch (n) {
             0...7 => self.push(@enumFromInt(0xD3 + @as(u8, @intCast(n))), .{ .u64 = 0 }),
-            8...11 => @panic("UNIMPLEMENTED"),
+            8...9 => @panic("UNIMPLEMENTED"),
+            10...11 => {
+                try self.push(@enumFromInt(0xD3 + @as(u8, @intCast(n))), .{ .u64 = 0 });
+                _ = try self.parser.readByte();
+                if (n == 10) {
+                    _ = try self.parser.readByte();
+                }
+            },
             12...17 => @panic("UNIMPLEMENTED"),
             else => {
                 std.log.err("Invalid misc instruction {d} at position {d}\n", .{ n, self.parser.byte_idx });
@@ -807,6 +814,18 @@ const IRParserState = struct {
         try self.push(@enumFromInt(b), .{ .u64 = 0 });
     }
 
+    fn parseTableBranch(self: *IRParserState, b: u8) !void {
+        const n = try self.parser.readU32();
+        const idxs = try self.allocator.alloc(u32, n);
+        // defer self.allocator.free(idxs);
+        for (idxs) |*i| {
+            i.* = try self.parser.readU32();
+            try self.branches.put(self.allocator, @intCast(self.opcodes.items.len), i.*);
+        }
+        try self.branches.put(self.allocator, @intCast(self.opcodes.items.len), try self.parser.readU32());
+        try self.push(@enumFromInt(b), .{ .u64 = 0 });
+    }
+
     fn parseVector(self: *IRParserState) !void {
         const n = try self.parser.readU32();
         try switch (n) {
@@ -859,3 +878,19 @@ pub fn parseGlobalExpr(parser: *Parser) !IR {
         .select_valtypes = &.{},
     };
 }
+
+pub fn parseSingleExpr(parser: *Parser) !IR {
+    var state = IRParserState{
+        .opcodes = .{},
+        .indices = .{},
+        .branches = .{},
+        .parser = parser,
+        .allocator = parser.allocator,
+    };
+    try state.parseExpression();
+    return .{
+        .opcodes = try state.opcodes.toOwnedSlice(state.allocator),
+        .indices = try state.indices.toOwnedSlice(state.allocator),
+        .select_valtypes = &.{},
+    };
+}

src/mods/vm.zig

@@ -56,11 +56,13 @@ pub const Module = struct {
     exports: Exports,
     exported_memory: u32,
     imported_funcs: u32,
+    data: []const u8,
+    tables: []Parser.Tabletype,
+    elems: [][]u32,
 
     pub fn deinit(self: Module, allocator: Allocator) void {
         // self.exports.deinit(allocator);
         for (self.functions) |f| {
-            std.debug.print("Freeing function parameters at {*}\n", .{f.func_type.parameters.ptr});
             allocator.free(f.func_type.parameters);
             allocator.free(f.func_type.returns);
             switch (f.typ) {
@@ -103,6 +105,8 @@ pub const Runtime = struct {
             std.log.warn("Growing memory is not yet supported, usign the minimum memory\n", .{});
         }
         const memory = try allocator.alloc(u8, max);
+        std.crypto.secureZero(u8, memory);
+        @memcpy(memory[0..module.data.len], module.data);
         return Runtime{
             .module = module,
             .stack = try std.ArrayList(Value).initCapacity(allocator, 10),
@@ -112,7 +116,6 @@ pub const Runtime = struct {
     }
 
     pub fn deinit(self: *Runtime, allocator: Allocator) void {
-        self.module.deinit(allocator);
         self.stack.deinit();
         allocator.free(self.memory);
     }
@@ -131,7 +134,7 @@ pub const Runtime = struct {
                     continue;
                 },
                 .br_if => {
-                    if (self.stack.pop().?.i32 != 0) {
+                    if (self.stack.items[self.stack.items.len - 1].i32 != 0) {
                         frame.program_counter = index.u32;
                         continue;
                     }
@@ -140,13 +143,29 @@ pub const Runtime = struct {
                 .@"return" => break :loop,
                 .call => {
                     if (index.u32 == self.module.exports.logDebug) {
-                        std.debug.print("TODO: logDebug\n", .{});
+                        const size: usize = @intCast(self.stack.pop().?.i64);
+                        const offset: usize = @intCast(self.stack.pop().?.i32);
+                        const ptr: []u8 = self.memory[offset .. offset + size];
+                        const extra: u8 = if (ptr.len > 0 and ptr[ptr.len - 1] != '\n') 0x0a else 0;
+                        std.debug.print("[DEBUG]: {s}{c}", .{ptr, extra});
                     } else if (index.u32 == self.module.exports.logInfo) {
-                        std.debug.print("TODO: logInfo\n", .{});
+                        const size: usize = @intCast(self.stack.pop().?.i64);
+                        const offset: usize = @intCast(self.stack.pop().?.i32);
+                        const ptr: []u8 = self.memory[offset .. offset + size];
+                        const extra: u8 = if (ptr.len > 0 and ptr[ptr.len - 1] != '\n') 0x0a else 0;
+                        std.debug.print("[INFO]: {s}{c}", .{ptr, extra});
                     } else if (index.u32 == self.module.exports.logWarn) {
-                        std.debug.print("TODO: logWarn\n", .{});
+                        const size: usize = @intCast(self.stack.pop().?.i64);
+                        const offset: usize = @intCast(self.stack.pop().?.i32);
+                        const ptr: []u8 = self.memory[offset .. offset + size];
+                        const extra: u8 = if (ptr.len > 0 and ptr[ptr.len - 1] != '\n') 0x0a else 0;
+                        std.debug.print("[WARN]: {s}{c}", .{ptr, extra});
                     } else if (index.u32 == self.module.exports.logErr) {
-                        std.debug.print("TODO: logErr\n", .{});
+                        const size: usize = @intCast(self.stack.pop().?.i64);
+                        const offset: usize = @intCast(self.stack.pop().?.i32);
+                        const ptr: []u8 = self.memory[offset .. offset + size];
+                        const extra: u8 = if (ptr.len > 0 and ptr[ptr.len - 1] != '\n') 0x0a else 0;
+                        std.debug.print("[ERROR]: {s}{c}", .{ptr, extra});
                     } else {
                         var parameters = std.ArrayList(Value).init(allocator);
                         defer parameters.deinit();
@@ -156,7 +175,19 @@ pub const Runtime = struct {
                         try self.call(allocator, index.u32 - self.module.imported_funcs, parameters.items);
                     }
                 },
-                .call_indirect => @panic("UNIMPLEMENTED"),
+                .call_indirect => {
+                    std.debug.panic("call_indirect: {any}\n", .{self.stack.pop().?});
+                    if (self.module.tables[index.indirect.x].et != std.wasm.RefType.funcref) {
+                        std.debug.panic("Table at index {any} is not a `funcref` table\n", .{index.indirect.x});
+                    }
+                    const funcIdx = self.module.elems[index.indirect.x][index.indirect.y];
+                    var parameters = std.ArrayList(Value).init(allocator);
+                    defer parameters.deinit();
+                    for (self.module.functions[funcIdx - self.module.imported_funcs].func_type.parameters) |_| {
+                        try parameters.append(self.stack.pop().?);
+                    }
+                    try self.call(allocator, funcIdx - self.module.imported_funcs, parameters.items);
+                },
 
                 .refnull => @panic("UNIMPLEMENTED"),
                 .refisnull => @panic("UNIMPLEMENTED"),
@@ -194,27 +225,35 @@ pub const Runtime = struct {
 
                 // TODO(ernesto): This code is repeated...
                 .i32_load => {
-                    const start = index.memarg.alignment + index.memarg.offset;
+                    const offsetVal = self.stack.pop().?.i32;
+                    if (offsetVal < 0) {
+                        std.debug.panic("offsetVal is negative (val: {any} arg: {any})\n", .{ offsetVal, index.memarg });
+                    }
+                    const start = index.memarg.offset + @as(u32, @intCast(offsetVal));
                     const end = start + @sizeOf(i32);
                     try self.stack.append(.{ .i32 = std.mem.littleToNative(i32, std.mem.bytesAsValue(i32, self.memory[start..end]).*) });
                 },
                 .i64_load => {
-                    const start = index.memarg.alignment + index.memarg.offset;
+                    const start = index.memarg.offset + @as(u32, @intCast(self.stack.pop().?.i32));
                     const end = start + @sizeOf(i64);
                     try self.stack.append(.{ .i64 = std.mem.littleToNative(i64, std.mem.bytesAsValue(i64, self.memory[start..end]).*) });
                 },
                 .f32_load => {
-                    const start = index.memarg.alignment + index.memarg.offset;
+                    const start = index.memarg.offset + @as(u32, @intCast(self.stack.pop().?.i32));
                     const end = start + @sizeOf(f32);
                     try self.stack.append(.{ .f32 = std.mem.littleToNative(f32, std.mem.bytesAsValue(f32, self.memory[start..end]).*) });
                 },
                 .f64_load => {
-                    const start = index.memarg.alignment + index.memarg.offset;
+                    const start = index.memarg.offset + @as(u32, @intCast(self.stack.pop().?.i32));
                     const end = start + @sizeOf(f64);
                     try self.stack.append(.{ .f64 = std.mem.littleToNative(f64, std.mem.bytesAsValue(f64, self.memory[start..end]).*) });
                 },
                 .i32_load8_s => @panic("UNIMPLEMENTED"),
-                .i32_load8_u => @panic("UNIMPLEMENTED"),
+                .i32_load8_u => {
+                    const start = index.memarg.offset + @as(u32, @intCast(self.stack.pop().?.i32));
+                    const end = start + @sizeOf(u8);
+                    try self.stack.append(.{ .i32 = std.mem.littleToNative(u8, std.mem.bytesAsValue(u8, self.memory[start..end]).*) });
+                },
                 .i32_load16_s => @panic("UNIMPLEMENTED"),
                 .i32_load16_u => @panic("UNIMPLEMENTED"),
                 .i64_load8_s => @panic("UNIMPLEMENTED"),
@@ -222,24 +261,58 @@ pub const Runtime = struct {
                 .i64_load16_s => @panic("UNIMPLEMENTED"),
                 .i64_load16_u => @panic("UNIMPLEMENTED"),
                 .i64_load32_s => @panic("UNIMPLEMENTED"),
-                .i64_load32_u => @panic("UNIMPLEMENTED"),
+                .i64_load32_u => {
-                .i32_store => @panic("UNIMPLEMENTED"),
+                    const start = index.memarg.offset + @as(u32, @intCast(self.stack.pop().?.i32));
-                .i64_store => {
+                    const end = start + @sizeOf(u32);
-                    // TODO(ernesto): I'm pretty sure this is wrong
+                    const raw_value = std.mem.readInt(u32, @as(*const [4]u8, @ptrCast(self.memory[start..end])), std.builtin.Endian.little);
-                    const val = std.mem.nativeToLittle(i64, self.stack.pop().?.i64);
+                    try self.stack.append(.{ .i64 = @intCast(@as(u64, raw_value)) });  // Zero-extend
+                },
+                .i32_store => {
+                    const val = std.mem.nativeToLittle(i32, self.stack.pop().?.i32);
                     const offsetVal = self.stack.pop().?.i32;
                     if (offsetVal < 0) {
                         std.debug.panic("offsetVal is negative (val: {any})\n", .{offsetVal});
                     }
                     const offset: u64 = @intCast(offsetVal);
                     const start: usize = @intCast(@as(u64, index.memarg.offset) + offset);
+                    const end = start + @sizeOf(u32);
+                    @memcpy(self.memory[start..end], std.mem.asBytes(&val));
+                },
+                .i64_store => {
+                    const val = std.mem.nativeToLittle(i64, self.stack.pop().?.i64);
+                    const offsetVal = self.stack.pop().?.i32;
+                    if (offsetVal < 0) {
+                        std.debug.panic("offsetVal is negative (val: {any} ip: {any} prev: {any} next: {any})\n", .{ offsetVal, frame.program_counter, frame.code.opcodes[frame.program_counter - 1], frame.code.opcodes[frame.program_counter + 1] });
+                    }
+                    const offset: u64 = @intCast(offsetVal);
+                    const start: usize = @intCast(@as(u64, index.memarg.offset) + offset);
                     const end = start + @sizeOf(u64);
                     @memcpy(self.memory[start..end], std.mem.asBytes(&val));
                 },
                 .f32_store => @panic("UNIMPLEMENTED"),
                 .f64_store => @panic("UNIMPLEMENTED"),
-                .i32_store8 => @panic("UNIMPLEMENTED"),
+                .i32_store8 => {
-                .i32_store16 => @panic("UNIMPLEMENTED"),
+                    const val = std.mem.nativeToLittle(i8, @as(i8, @intCast(self.stack.pop().?.i32)));
+                    const offsetVal = self.stack.pop().?.i32;
+                    if (offsetVal < 0) {
+                        std.debug.panic("offsetVal is negative (val: {any})\n", .{offsetVal});
+                    }
+                    const offset: u64 = @intCast(offsetVal);
+                    const start: usize = @intCast(@as(u64, index.memarg.offset) + offset);
+                    const end = start + @sizeOf(u8);
+                    @memcpy(self.memory[start..end], std.mem.asBytes(&val));
+                },
+                .i32_store16 => {
+                    const val = std.mem.nativeToLittle(i16, @as(i16, @intCast(self.stack.pop().?.i32)));
+                    const offsetVal = self.stack.pop().?.i32;
+                    if (offsetVal < 0) {
+                        std.debug.panic("offsetVal is negative (val: {any})\n", .{offsetVal});
+                    }
+                    const offset: u64 = @intCast(offsetVal);
+                    const start: usize = @intCast(@as(u64, index.memarg.offset) + offset);
+                    const end = start + @sizeOf(u16);
+                    @memcpy(self.memory[start..end], std.mem.asBytes(&val));
+                },
                 .i64_store8 => @panic("UNIMPLEMENTED"),
                 .i64_store16 => @panic("UNIMPLEMENTED"),
                 .i64_store32 => @panic("UNIMPLEMENTED"),
@@ -248,8 +321,18 @@ pub const Runtime = struct {
                 .memorygrow => @panic("UNIMPLEMENTED"),
                 .memoryinit => @panic("UNIMPLEMENTED"),
                 .datadrop => @panic("UNIMPLEMENTED"),
-                .memorycopy => @panic("UNIMPLEMENTED"),
+                .memorycopy => {
-                .memoryfill => @panic("UNIMPLEMENTED"),
+                    const bytes: usize = @intCast(self.stack.pop().?.i32);
+                    const source: usize = @intCast(self.stack.pop().?.i32);
+                    const dest: usize = @intCast(self.stack.pop().?.i32);
+                    @memcpy(self.memory[dest .. dest + bytes], self.memory[source .. source + bytes]);
+                },
+                .memoryfill => {
+                    const bytes: usize = @intCast(self.stack.pop().?.i32);
+                    const val: u8 = @as(u8, @intCast(self.stack.pop().?.i32));
+                    const dest: usize = @intCast(self.stack.pop().?.i32);
+                    @memset(self.memory[dest .. dest + bytes], val);
+                },
 
                 .i32_const => {
                     try self.stack.append(Value{ .i32 = frame.code.indices[frame.program_counter].i32 });
@@ -264,34 +347,46 @@ pub const Runtime = struct {
                     try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 == 0))) });
                 },
                 .i32_eq => @panic("UNIMPLEMENTED"),
-                .i32_ne => @panic("UNIMPLEMENTED"),
+                .i32_ne => {
+                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(a != b))) });
+                },
                 .i32_lt_s => @panic("UNIMPLEMENTED"),
                 .i32_lt_u => {
-                    const b = self.stack.pop().?.i32;
                     const a = self.stack.pop().?.i32;
-                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(a < b))) });
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(b < a))) });
                 },
                 .i32_gt_s => @panic("UNIMPLEMENTED"),
-                .i32_gt_u => @panic("UNIMPLEMENTED"),
+                .i32_gt_u => {
+                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(b > a))) });
+                },
                 .i32_le_s => @panic("UNIMPLEMENTED"),
-                .i32_le_u => @panic("UNIMPLEMENTED"),
+                .i32_le_u => {
+                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(b <= a))) });
+                },
                 .i32_ge_s => @panic("UNIMPLEMENTED"),
                 .i32_ge_u => {
-                    const b = self.stack.pop().?.i32;
                     const a = self.stack.pop().?.i32;
-                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(a >= b))) });
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(b >= a))) });
                 },
 
                 .i64_eqz => {
-                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i32 == 0))) });
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(self.stack.pop().?.i64 == 0))) });
                 },
                 .i64_eq => @panic("UNIMPLEMENTED"),
                 .i64_ne => @panic("UNIMPLEMENTED"),
                 .i64_lt_s => @panic("UNIMPLEMENTED"),
                 .i64_lt_u => {
-                    const b = self.stack.pop().?.i32;
+                    const a = self.stack.pop().?.i64;
-                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i64;
-                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(a < b))) });
+                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(b < a))) });
                 },
                 .i64_gt_s => @panic("UNIMPLEMENTED"),
                 .i64_gt_u => @panic("UNIMPLEMENTED"),
@@ -323,23 +418,39 @@ pub const Runtime = struct {
                     try self.stack.append(Value{ .i32 = a + b });
                 },
                 .i32_sub => {
-                    const b = self.stack.pop().?.i32;
                     const a = self.stack.pop().?.i32;
-                    try self.stack.append(Value{ .i32 = a - b });
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = b - a });
                 },
                 .i32_and => {
                     const a = self.stack.pop().?.i32;
                     const b = self.stack.pop().?.i32;
                     try self.stack.append(Value{ .i32 = a & b });
                 },
-                .i32_mul => @panic("UNIMPLEMENTED"),
+                .i32_mul => {
+                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = a * b });
+                },
                 .i32_div_s => @panic("UNIMPLEMENTED"),
-                .i32_div_u => @panic("UNIMPLEMENTED"),
+                .i32_div_u => {
+                    const a_unsigned = @as(u32, @bitCast(self.stack.pop().?.i32));
+                    const b_unsigned = @as(u32, @bitCast(self.stack.pop().?.i32));
+                    try self.stack.append(Value{ .i32 = @bitCast(b_unsigned / a_unsigned) });
+                },
                 .i32_rem_s => @panic("UNIMPLEMENTED"),
                 .i32_rem_u => @panic("UNIMPLEMENTED"),
-                .i32_or => @panic("UNIMPLEMENTED"),
+                .i32_or => {
+                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = a | b });
+                },
                 .i32_xor => @panic("UNIMPLEMENTED"),
-                .i32_shl => @panic("UNIMPLEMENTED"),
+                .i32_shl => {
+                    const a = self.stack.pop().?.i32;
+                    const b = self.stack.pop().?.i32;
+                    try self.stack.append(Value{ .i32 = (b << @as(u5, @intCast(a))) });
+                },
                 .i32_shr_s => @panic("UNIMPLEMENTED"),
                 .i32_shr_u => @panic("UNIMPLEMENTED"),
                 .i32_rotl => @panic("UNIMPLEMENTED"),
@@ -463,8 +574,19 @@ pub const Runtime = struct {
         }
     }
 
+    fn reverseSlice(slice: []Value) void {
+        var i: usize = 0;
+        var j = slice.len - 1;
+        while (i < j) {
+            std.mem.swap(Value, &slice[i], &slice[j]);
+            i += 1;
+            j -= 1;
+        }
+    }
+
     pub fn call(self: *Runtime, allocator: Allocator, function: usize, parameters: []Value) AllocationError!void {
         const f = self.module.functions[function];
+        reverseSlice(parameters);
         switch (f.typ) {
             .internal => {
                 const ir: IR = f.typ.internal.ir;

src/sideros.zig

@@ -1,5 +1,6 @@
 pub const ecs = @import("ecs");
 pub const Renderer = @import("renderer");
+pub const mods = @import("mods");
 
 const api = @cImport({
     @cInclude("sideros_api.h");
@@ -12,6 +13,35 @@ const allocator = gpa.allocator();
 var pool: ecs.Pool = undefined;
 var renderer: Renderer = undefined;
 
+fn init_mods() void {
+    var global_runtime = mods.GlobalRuntime.init(allocator);
+    defer global_runtime.deinit();
+
+    // const file = std.fs.cwd().openFile("assets/core.wasm", .{}) catch @panic("Couldn't open assets/core.wasm");
+    const file = std.fs.cwd().openFile("./test.wasm", .{}) catch @panic("Couldn't open test.wasm");
+    const all = file.readToEndAlloc(allocator, 1_000_000) catch @panic("Unable to read the file"); // 1 MB
+    defer allocator.free(all);
+    var parser = mods.Parser.init(allocator, all) catch @panic("Failed to init parser");
+    defer parser.deinit();
+    parser.parseModule() catch |err| {
+       std.debug.panic("[ERROR]: error {any} at byte {x}(0x{x})\n", .{ err, parser.byte_idx, parser.bytes[parser.byte_idx] });
+    };
+    const module = parser.module();
+    defer module.deinit(allocator);
+
+    for (0..parser.globalTypes.len) |i| {
+        global_runtime.addGlobal(@intCast(i), parser.globalTypes[i], parser.globalValues[i]) catch @panic("Failed to add runtime global");
+    }
+
+    var runtime = mods.Runtime.init(allocator, module, &global_runtime) catch @panic("Failed to init runtime");
+    defer runtime.deinit(allocator);
+
+    var parameters = [_]mods.VM.Value{.{ .i32 = 17 }};
+    runtime.callExternal(allocator, .preinit, &parameters) catch @panic("Failed to call to preinit");
+    const result = runtime.stack.pop().?;
+    std.debug.print("Result of preinit: {any}\n", .{result});
+}
+
 export fn sideros_init(init: api.GameInit) callconv(.c) void {
     pool = ecs.Pool.init(allocator, .{
         .camera = .{
@@ -26,6 +56,7 @@ export fn sideros_init(init: api.GameInit) callconv(.c) void {
     pool.addSystemGroup(&[_]ecs.System{Renderer.render}, true) catch @panic("TODO: Gracefuly handle error");
     pool.resources.renderer = &renderer;
     pool.tick();
+    // init_mods();
 }
 
 export fn sideros_update(gameUpdate: api.GameUpdate) callconv(.c) void {