esp: Wi-Fi support

core/src/interrupt.zig

@@ -122,9 +122,10 @@ pub const CriticalSectionMutex = struct {
 
     /// Unlocks the mutex.
     pub fn unlock(self: *CriticalSectionMutex) void {
-        if (self.critical_section) |cs| {
+        const maybe_cs = self.critical_section;
+        self.critical_section = null;
+        if (maybe_cs) |cs| {
             cs.leave();
-            self.critical_section = null;
         }
     }
 };

examples/espressif/esp/build.zig

@@ -12,13 +12,7 @@ pub fn build(b: *std.Build) void {
     const mz_dep = b.dependency("microzig", .{});
     const mb = MicroBuild.init(b, mz_dep) orelse return;
 
-    const targets = [_]TargetDescription{
-        .{ .prefix = "esp32_c3", .target = mb.ports.esp.chips.esp32_c3 },
-        .{ .prefix = "esp32_c3_direct_boot", .target = mb.ports.esp.chips.esp32_c3_direct_boot },
-        .{ .prefix = "esp32_c3_flashless", .target = mb.ports.esp.chips.esp32_c3_flashless },
-    };
-
-    const available_examples = [_]Example{
+    const examples: []const Example = &.{
         .{ .name = "blinky", .file = "src/blinky.zig" },
         .{ .name = "custom_clock_config", .file = "src/custom_clock_config.zig" },
         .{ .name = "gpio_input", .file = "src/gpio_input.zig" },
@@ -30,15 +24,25 @@ pub fn build(b: *std.Build) void {
         .{ .name = "stepper_driver_dumb", .file = "src/stepper_driver_dumb.zig" },
         .{ .name = "systimer", .file = "src/systimer.zig" },
         .{ .name = "ws2812_blinky", .file = "src/ws2812_blinky.zig" },
+        .{ .name = "rtos", .file = "src/rtos.zig" },
+        .{ .name = "tcp_server", .file = "src/tcp_server.zig", .features = .{
+            .flashless = false,
+            .lwip = true,
+        } },
     };
 
-    for (available_examples) |example| {
+    for (examples) |example| {
         // If we specify example, only select the ones that match
         if (maybe_example) |selected_example|
             if (!std.mem.containsAtLeast(u8, example.name, 1, selected_example))
                 continue;
 
-        for (targets) |target_desc| {
+        for (std.enums.values(TargetEnum)) |target_enum| {
+            if (!example.features.flashless and std.mem.containsAtLeast(u8, @tagName(target_enum), 1, "flashless"))
+                continue;
+
+            const target_desc = target_enum.get_target_desc(mb);
+
             // `add_firmware` basically works like addExecutable, but takes a
             // `microzig.Target` for target instead of a `std.zig.CrossTarget`.
             //
@@ -51,6 +55,28 @@ pub fn build(b: *std.Build) void {
                 .root_source_file = b.path(example.file),
             });
 
+            if (example.features.lwip) {
+                const target = b.resolveTargetQuery(firmware.target.zig_target);
+
+                const foundation_dep = b.dependency("foundation_libc", .{
+                    .target = target,
+                    .optimize = optimize,
+                    .single_threaded = true,
+                });
+
+                const lwip_dep = b.dependency("lwip", .{
+                    .target = target,
+                    .optimize = optimize,
+                    .include_dir = b.path("src/lwip/include"),
+                });
+
+                const libc_lib = foundation_dep.artifact("foundation");
+                const lwip_lib = lwip_dep.artifact("lwip");
+
+                lwip_lib.root_module.linkLibrary(libc_lib);
+                firmware.app_mod.linkLibrary(lwip_lib);
+            }
+
             // `installFirmware()` is the MicroZig pendant to `Build.installArtifact()`
             // and allows installing the firmware as a typical firmware file.
             //
@@ -63,12 +89,146 @@ pub fn build(b: *std.Build) void {
     }
 }
 
+const TargetEnum = enum {
+    esp32_c3,
+    esp32_c3_direct_boot,
+    esp32_c3_flashless,
+
+    fn get_target_desc(target_enum: TargetEnum, mb: *MicroBuild) TargetDescription {
+        return switch (target_enum) {
+            .esp32_c3 => .{
+                .prefix = "esp32_c3",
+                .target = mb.ports.esp.chips.esp32_c3,
+            },
+            .esp32_c3_direct_boot => .{
+                .prefix = "esp32_c3_direct_boot",
+                .target = mb.ports.esp.chips.esp32_c3_direct_boot,
+            },
+            .esp32_c3_flashless => .{
+                .prefix = "esp32_c3_flashless",
+                .target = mb.ports.esp.chips.esp32_c3_flashless,
+            },
+        };
+    }
+};
+
 const TargetDescription = struct {
     prefix: []const u8,
     target: *const microzig.Target,
 };
 
 const Example = struct {
+    const Features = packed struct {
+        flashless: bool = true,
+        lwip: bool = false,
+    };
+
     name: []const u8,
     file: []const u8,
+    features: Features = .{},
+};
+
+const lwip_flags = [_][]const u8{ "-std=c99", "-fno-sanitize=undefined" };
+const lwip_files = [_][]const u8{
+    // Core files
+    "core/init.c",
+    "core/def.c",
+    "core/dns.c",
+    "core/inet_chksum.c",
+    "core/ip.c",
+    "core/mem.c",
+    "core/memp.c",
+    "core/netif.c",
+    "core/pbuf.c",
+    "core/raw.c",
+    "core/stats.c",
+    "core/sys.c",
+    "core/altcp.c",
+    "core/altcp_alloc.c",
+    "core/altcp_tcp.c",
+    "core/tcp.c",
+    "core/tcp_in.c",
+    "core/tcp_out.c",
+    "core/timeouts.c",
+    "core/udp.c",
+
+    // IPv4 implementation:
+    "core/ipv4/acd.c",
+    "core/ipv4/autoip.c",
+    "core/ipv4/dhcp.c",
+    "core/ipv4/etharp.c",
+    "core/ipv4/icmp.c",
+    "core/ipv4/igmp.c",
+    "core/ipv4/ip4_frag.c",
+    "core/ipv4/ip4.c",
+    "core/ipv4/ip4_addr.c",
+
+    // IPv6 implementation:
+    "core/ipv6/dhcp6.c",
+    "core/ipv6/ethip6.c",
+    "core/ipv6/icmp6.c",
+    "core/ipv6/inet6.c",
+    "core/ipv6/ip6.c",
+    "core/ipv6/ip6_addr.c",
+    "core/ipv6/ip6_frag.c",
+    "core/ipv6/mld6.c",
+    "core/ipv6/nd6.c",
+
+    // Interfaces
+    "netif/ethernet.c",
+
+    // Interfaces:
+    // "netif/bridgeif.c",
+    // "netif/ethernet.c",
+    // "netif/slipif.c",
+    // "netif/bridgeif_fdb.c",
+
+    // sequential APIs
+    // "api/err.c",
+    // "api/api_msg.c",
+    // "api/netifapi.c",
+    // "api/sockets.c",
+    // "api/netbuf.c",
+    // "api/api_lib.c",
+    // "api/tcpip.c",
+    // "api/netdb.c",
+    // "api/if_api.c",
+
+    // 6LoWPAN
+    // "netif/lowpan6.c",
+    // "netif/lowpan6_ble.c",
+    // "netif/lowpan6_common.c",
+    // "netif/zepif.c",
+
+    // PPP
+    // "netif/ppp/polarssl/arc4.c",
+    // "netif/ppp/polarssl/des.c",
+    // "netif/ppp/polarssl/md4.c",
+    // "netif/ppp/polarssl/sha1.c",
+    // "netif/ppp/polarssl/md5.c",
+    // "netif/ppp/ipcp.c",
+    // "netif/ppp/magic.c",
+    // "netif/ppp/pppoe.c",
+    // "netif/ppp/mppe.c",
+    // "netif/ppp/multilink.c",
+    // "netif/ppp/chap-new.c",
+    // "netif/ppp/auth.c",
+    // "netif/ppp/chap_ms.c",
+    // "netif/ppp/ipv6cp.c",
+    // "netif/ppp/chap-md5.c",
+    // "netif/ppp/upap.c",
+    // "netif/ppp/pppapi.c",
+    // "netif/ppp/pppos.c",
+    // "netif/ppp/eap.c",
+    // "netif/ppp/pppol2tp.c",
+    // "netif/ppp/demand.c",
+    // "netif/ppp/fsm.c",
+    // "netif/ppp/eui64.c",
+    // "netif/ppp/ccp.c",
+    // "netif/ppp/pppcrypt.c",
+    // "netif/ppp/utils.c",
+    // "netif/ppp/vj.c",
+    // "netif/ppp/lcp.c",
+    // "netif/ppp/ppp.c",
+    // "netif/ppp/ecp.c",
 };

examples/espressif/esp/build.zig.zon

@@ -4,6 +4,8 @@
     .version = "0.0.0",
     .dependencies = .{
         .microzig = .{ .path = "../../.." },
+        .lwip = .{ .path = "../../../modules/lwip" },
+        .foundation_libc = .{ .path = "../../../modules/foundation-libc" },
     },
     .paths = .{
         "README.md",