Rewrite STM32 blinky to easily add other boards/chips.

examples/stmicro/stm32/src/blinky.zig

@@ -2,21 +2,39 @@ const std = @import("std");
 const microzig = @import("microzig");
 const stm32 = microzig.hal;
 
-const pin_config = stm32.pins.GlobalConfiguration{
-    .GPIOC = .{
-        .PIN13 = .{ .name = "led", .mode = .{ .output = .general_purpose_push_pull } },
-    },
-};
+fn delay() void {
+    var i: u32 = 0;
+    while (i < 800_000) {
+        asm volatile ("nop");
+        i += 1;
+    }
+}
 
 pub fn main() !void {
-    const pins = pin_config.apply();
+    const pins, const all_leds = res: {
+        if (comptime std.mem.eql(u8, microzig.config.chip_name, "STM32F103C8")) {
+            const pins = (stm32.pins.GlobalConfiguration{ .GPIOC = .{
+                .PIN13 = .{ .name = "led", .mode = .{ .output = .general_purpose_push_pull } },
+            } }).apply();
+            const all_leds = .{
+                pins.led,
+            };
+            break :res .{ pins, all_leds };
+        } else {
+            @compileError("blinky is not (yet?) implemented for this target");
+        }
+    };
+    _ = pins;
 
     while (true) {
-        var i: u32 = 0;
-        while (i < 800_000) {
-            asm volatile ("nop");
-            i += 1;
+        delay();
+        for (0..all_leds.len) |k| {
+            switch (@as(u3, @intCast(k))) {
+                inline else => |i| {
+                    if (i >= all_leds.len) unreachable;
+                    all_leds[i].toggle();
+                },
+            }
         }
-        pins.led.toggle();
     }
 }