test: verify linker error without export_startup#943
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The firmware executable's root module is now the user's application
source, not microzig's start.zig shim. This aligns microzig with the
standard Zig build idiom: `@import("root")` from any module resolves to
user code, `pub const panic` / `pub const std_options` live where Zig
expects to find them, and tooling that assumes root-is-the-app now
works naturally.
Core changes:
- microzig.zig reads `microzig_options` via `@import("root")` instead of
the injected `app` module, and drops the `pub const app` alias.
- utilities.install_startup / core/src/start.zig are replaced by a
single user-facing primitive, `microzig.export_startup()`, which the
application opts into from a comptime block. It emits the CPU
startup symbols and the `microzig_main` wrapper that the CPU `_start`
calls once `.data`/`.bss` are initialized.
- Startup logic (HAL init / root init / error-returning main / panic
wrapping) moves out of start.zig into microzig_main, with identical
semantics.
- A new `microzig.std_options()` helper returns a `std.Options` with
microzig's freestanding-safe defaults (the critical one being a no-op
`logFn` that replaces stdlib's stderr-writing default, which fails to
link on freestanding). The accompanying `StdOptions` struct documents
which std.Options fields are exposed and which are intentionally
excluded as hosted-only.
- The log-related fields (`log_level`, `log_scope_levels`, `logFn`) are
removed from `microzig.Options`; they now live exclusively in
`std.Options` via the helper.
Build system:
- `add_firmware` sets `exe.root_module = app_mod` directly. The
separate start.zig root module and the "app"-import plumbing on
`core_mod` / `cpu_mod` / `chip_mod` / `hal_mod` / `board_mod` are
all gone.
Example boilerplate (now two re-exports and one comptime line):
pub const panic = microzig.panic;
pub const std_options = microzig.std_options(.{});
comptime {
_ = microzig.export_startup();
}
All 131 example main.zig files have been migrated. Examples that
previously declared `pub const microzig_options` with log-related
fields have had those fields moved into `microzig.std_options(...)`,
with any remaining microzig-specific fields (interrupts, hal, cpu,
etc.) kept in a trimmed `pub const microzig_options`.
The website getting-started snippet is updated to match.
This commit only performs the structural move. It is NOT expected to
build against 0.15.x or current 0.16.x compilers as-is; the separate
0.16 migration work comes next.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Test complete. forceUndefinedSymbol does NOT catch missing export_startup() — see analysis. |
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Temporary PR to verify that
forceUndefinedSymbol("microzig_main")produces a clear linker error when a user forgets to callmicrozig.export_startup(). Will be closed immediately after.