Desktop Phase 1: add 77 tests to evdevd, udev-shim, firmware-loader

Phase 1 desktop substrate test coverage for the three runtime services that must be runtime-trusted before compositor work begins: - evdevd device.rs: 44 tests (input device constructors, capability bitmaps, key/led state tracking, abs_info defaults/overrides, bitmap_from_codes edge cases) - udev-shim device_db.rs: 13 tests (DeviceInfo construction, subsystem naming, id_path formatting, input kind detection, property formatting for GPU/keyboard/mouse, device_info/uevent output, PCI fallback) - firmware-loader scheme.rs: 20 tests (openat validation, read offsets, fstat/fsize, EROFS enforcement, mmap_prep bounds, mmap/munmap/on_close deferred cleanup lifecycle) Total: 65 evdevd, 15 udev-shim, 24 firmware-loader — all passing.
2026-04-25 01:05:14 +01:00
parent f7ffafa0c4
commit 3ec32b3351
3 changed files with 1071 additions and 1 deletions
@@ -230,3 +230,458 @@ fn bitmap_from_codes(codes: &[u16]) -> Vec<u8> {
    }
    bitmap
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::types::{
+        ABS_MT_POSITION_X, ABS_MT_POSITION_Y, ABS_MT_SLOT, ABS_MT_TOUCH_MAJOR, ABS_MT_TRACKING_ID,
+        ABS_PRESSURE, ABS_X, ABS_Y, BTN_LEFT, BTN_TOUCH, BUS_VIRTUAL, EV_ABS, EV_KEY, EV_LED,
+        EV_MSC, EV_REL, EV_REP, EV_SYN, INPUT_PROP_POINTER, KEY_A, LED_CAPSL, LED_NUML,
+        LED_SCROLLL, MSC_SCAN, REL_HWHEEL, REL_WHEEL, REL_X, REL_Y,
+    };
+
+    // Helper: check that a bitmap has the expected bit set for a given code.
+    fn assert_bit_set(bitmap: &[u8], code: u16) {
+        let byte = (code / 8) as usize;
+        let bit = code % 8;
+        assert!(
+            byte < bitmap.len(),
+            "code {} (byte index {}) out of bitmap range (len {})",
+            code,
+            byte,
+            bitmap.len()
+        );
+        assert_eq!(
+            bitmap[byte] & (1 << bit),
+            1 << bit,
+            "bit {} in byte {} not set for code {}",
+            bit,
+            byte,
+            code
+        );
+    }
+
+    fn assert_bit_clear(bitmap: &[u8], code: u16) {
+        let byte = (code / 8) as usize;
+        let bit = code % 8;
+        if byte < bitmap.len() {
+            assert_eq!(
+                bitmap[byte] & (1 << bit),
+                0,
+                "bit {} in byte {} unexpectedly set for code {}",
+                bit,
+                byte,
+                code
+            );
+        }
+    }
+
+    // ---------------------------------------------------------------
+    // 1. InputDevice::new_keyboard
+    // ---------------------------------------------------------------
+    #[test]
+    fn new_keyboard_has_correct_kind() {
+        let dev = InputDevice::new_keyboard(3);
+        assert_eq!(dev.kind, DeviceKind::Keyboard);
+    }
+
+    #[test]
+    fn new_keyboard_name_format() {
+        let dev = InputDevice::new_keyboard(7);
+        assert_eq!(dev.name, "Redox Keyboard 7");
+    }
+
+    #[test]
+    fn new_keyboard_input_id_bus_virtual() {
+        let dev = InputDevice::new_keyboard(1);
+        assert_eq!(dev.input_id.bustype, BUS_VIRTUAL);
+        assert_eq!(dev.input_id.vendor, 0);
+        assert_eq!(dev.input_id.product, 1);
+        assert_eq!(dev.input_id.version, 1);
+    }
+
+    #[test]
+    fn new_keyboard_key_and_led_state_zeroed() {
+        let dev = InputDevice::new_keyboard(0);
+        assert!(dev.key_state.iter().all(|&b| b == 0));
+        assert!(dev.led_state.iter().all(|&b| b == 0));
+    }
+
+    // ---------------------------------------------------------------
+    // 2. InputDevice::new_mouse
+    // ---------------------------------------------------------------
+    #[test]
+    fn new_mouse_has_correct_kind() {
+        let dev = InputDevice::new_mouse(2);
+        assert_eq!(dev.kind, DeviceKind::Mouse);
+    }
+
+    #[test]
+    fn new_mouse_name_format() {
+        let dev = InputDevice::new_mouse(5);
+        assert_eq!(dev.name, "Redox Mouse 5");
+    }
+
+    #[test]
+    fn new_mouse_product_id_offset() {
+        let dev = InputDevice::new_mouse(3);
+        assert_eq!(dev.input_id.product, 3 + 0x10);
+        assert_eq!(dev.input_id.bustype, BUS_VIRTUAL);
+        assert_eq!(dev.input_id.version, 1);
+    }
+
+    #[test]
+    fn new_mouse_key_and_led_state_zeroed() {
+        let dev = InputDevice::new_mouse(0);
+        assert!(dev.key_state.iter().all(|&b| b == 0));
+        assert!(dev.led_state.iter().all(|&b| b == 0));
+    }
+
+    // ---------------------------------------------------------------
+    // 3. InputDevice::new_touchpad
+    // ---------------------------------------------------------------
+    #[test]
+    fn new_touchpad_has_correct_kind() {
+        let dev = InputDevice::new_touchpad(1);
+        assert_eq!(dev.kind, DeviceKind::Touchpad);
+    }
+
+    #[test]
+    fn new_touchpad_name_format() {
+        let dev = InputDevice::new_touchpad(4);
+        assert_eq!(dev.name, "Redox Touchpad 4");
+    }
+
+    #[test]
+    fn new_touchpad_product_id_offset() {
+        let dev = InputDevice::new_touchpad(2);
+        assert_eq!(dev.input_id.product, 2 + 0x20);
+        assert_eq!(dev.input_id.bustype, BUS_VIRTUAL);
+        assert_eq!(dev.input_id.version, 1);
+    }
+
+    // ---------------------------------------------------------------
+    // 4. supported_event_types
+    // ---------------------------------------------------------------
+    #[test]
+    fn keyboard_event_types() {
+        let dev = InputDevice::new_keyboard(0);
+        let bm = dev.supported_event_types();
+        assert_bit_set(&bm, EV_SYN);
+        assert_bit_set(&bm, EV_KEY);
+        assert_bit_set(&bm, EV_MSC);
+        assert_bit_set(&bm, EV_LED);
+        assert_bit_set(&bm, EV_REP);
+    }
+
+    #[test]
+    fn mouse_event_types() {
+        let dev = InputDevice::new_mouse(0);
+        let bm = dev.supported_event_types();
+        assert_bit_set(&bm, EV_SYN);
+        assert_bit_set(&bm, EV_KEY);
+        assert_bit_set(&bm, EV_REL);
+        // No EV_ABS for mouse
+        assert_bit_clear(&bm, EV_ABS);
+    }
+
+    #[test]
+    fn touchpad_event_types() {
+        let dev = InputDevice::new_touchpad(0);
+        let bm = dev.supported_event_types();
+        assert_bit_set(&bm, EV_SYN);
+        assert_bit_set(&bm, EV_KEY);
+        assert_bit_set(&bm, EV_ABS);
+        // No EV_REL for touchpad
+        assert_bit_clear(&bm, EV_REL);
+    }
+
+    // ---------------------------------------------------------------
+    // 5. supported_keys
+    // ---------------------------------------------------------------
+    #[test]
+    fn keyboard_has_key_a() {
+        let dev = InputDevice::new_keyboard(0);
+        let bm = dev.supported_keys();
+        assert_bit_set(&bm, KEY_A);
+    }
+
+    #[test]
+    fn mouse_has_btn_left() {
+        let dev = InputDevice::new_mouse(0);
+        let bm = dev.supported_keys();
+        assert_bit_set(&bm, BTN_LEFT);
+    }
+
+    #[test]
+    fn touchpad_has_btn_touch() {
+        let dev = InputDevice::new_touchpad(0);
+        let bm = dev.supported_keys();
+        assert_bit_set(&bm, BTN_TOUCH);
+    }
+
+    // ---------------------------------------------------------------
+    // 6. supported_rel
+    // ---------------------------------------------------------------
+    #[test]
+    fn mouse_rel_axes() {
+        let dev = InputDevice::new_mouse(0);
+        let bm = dev.supported_rel();
+        assert_bit_set(&bm, REL_X);
+        assert_bit_set(&bm, REL_Y);
+        assert_bit_set(&bm, REL_WHEEL);
+        assert_bit_set(&bm, REL_HWHEEL);
+    }
+
+    #[test]
+    fn keyboard_rel_empty() {
+        let dev = InputDevice::new_keyboard(0);
+        assert!(dev.supported_rel().is_empty());
+    }
+
+    #[test]
+    fn touchpad_rel_empty() {
+        let dev = InputDevice::new_touchpad(0);
+        assert!(dev.supported_rel().is_empty());
+    }
+
+    // ---------------------------------------------------------------
+    // 7. supported_abs
+    // ---------------------------------------------------------------
+    #[test]
+    fn touchpad_abs_axes() {
+        let dev = InputDevice::new_touchpad(0);
+        let bm = dev.supported_abs();
+        assert_bit_set(&bm, ABS_X);
+        assert_bit_set(&bm, ABS_Y);
+        assert_bit_set(&bm, ABS_PRESSURE);
+        assert_bit_set(&bm, ABS_MT_SLOT);
+        assert_bit_set(&bm, ABS_MT_TOUCH_MAJOR);
+        assert_bit_set(&bm, ABS_MT_POSITION_X);
+        assert_bit_set(&bm, ABS_MT_POSITION_Y);
+        assert_bit_set(&bm, ABS_MT_TRACKING_ID);
+    }
+
+    #[test]
+    fn keyboard_abs_empty() {
+        let dev = InputDevice::new_keyboard(0);
+        assert!(dev.supported_abs().is_empty());
+    }
+
+    #[test]
+    fn mouse_abs_empty() {
+        let dev = InputDevice::new_mouse(0);
+        assert!(dev.supported_abs().is_empty());
+    }
+
+    // ---------------------------------------------------------------
+    // 8. supported_msc
+    // ---------------------------------------------------------------
+    #[test]
+    fn keyboard_msc_has_scan() {
+        let dev = InputDevice::new_keyboard(0);
+        let bm = dev.supported_msc();
+        assert_bit_set(&bm, MSC_SCAN);
+    }
+
+    #[test]
+    fn mouse_msc_empty() {
+        let dev = InputDevice::new_mouse(0);
+        assert!(dev.supported_msc().is_empty());
+    }
+
+    #[test]
+    fn touchpad_msc_empty() {
+        let dev = InputDevice::new_touchpad(0);
+        assert!(dev.supported_msc().is_empty());
+    }
+
+    // ---------------------------------------------------------------
+    // 9. supported_leds
+    // ---------------------------------------------------------------
+    #[test]
+    fn keyboard_leds() {
+        let dev = InputDevice::new_keyboard(0);
+        let bm = dev.supported_leds();
+        assert_bit_set(&bm, LED_NUML);
+        assert_bit_set(&bm, LED_CAPSL);
+        assert_bit_set(&bm, LED_SCROLLL);
+    }
+
+    #[test]
+    fn mouse_leds_empty() {
+        let dev = InputDevice::new_mouse(0);
+        assert!(dev.supported_leds().is_empty());
+    }
+
+    #[test]
+    fn touchpad_leds_empty() {
+        let dev = InputDevice::new_touchpad(0);
+        assert!(dev.supported_leds().is_empty());
+    }
+
+    // ---------------------------------------------------------------
+    // 10. supported_props
+    // ---------------------------------------------------------------
+    #[test]
+    fn mouse_has_pointer_prop() {
+        let dev = InputDevice::new_mouse(0);
+        let bm = dev.supported_props();
+        assert_bit_set(&bm, INPUT_PROP_POINTER);
+    }
+
+    #[test]
+    fn touchpad_has_pointer_prop() {
+        let dev = InputDevice::new_touchpad(0);
+        let bm = dev.supported_props();
+        assert_bit_set(&bm, INPUT_PROP_POINTER);
+    }
+
+    #[test]
+    fn keyboard_props_empty() {
+        let dev = InputDevice::new_keyboard(0);
+        assert!(dev.supported_props().is_empty());
+    }
+
+    // ---------------------------------------------------------------
+    // 11. update_key_state
+    // ---------------------------------------------------------------
+    #[test]
+    fn update_key_state_press_sets_bit() {
+        let mut dev = InputDevice::new_keyboard(0);
+        // KEY_A = 30 → byte 3, bit 6
+        dev.update_key_state(KEY_A, true);
+        let byte = (KEY_A / 8) as usize;
+        let bit = KEY_A % 8;
+        assert_eq!(dev.key_state[byte] & (1 << bit), 1 << bit);
+    }
+
+    #[test]
+    fn update_key_state_release_clears_bit() {
+        let mut dev = InputDevice::new_keyboard(0);
+        dev.update_key_state(KEY_A, true);
+        assert_bit_set(&dev.key_state, KEY_A);
+        dev.update_key_state(KEY_A, false);
+        assert_bit_clear(&dev.key_state, KEY_A);
+    }
+
+    // ---------------------------------------------------------------
+    // 12. update_led_state
+    // ---------------------------------------------------------------
+    #[test]
+    fn update_led_state_set_capsl() {
+        let mut dev = InputDevice::new_keyboard(0);
+        // LED_CAPSL = 1 → byte 0, bit 1
+        dev.update_led_state(LED_CAPSL, true);
+        let byte = (LED_CAPSL / 8) as usize;
+        let bit = LED_CAPSL % 8;
+        assert_eq!(dev.led_state[byte] & (1 << bit), 1 << bit);
+    }
+
+    #[test]
+    fn update_led_state_clear_capsl() {
+        let mut dev = InputDevice::new_keyboard(0);
+        dev.update_led_state(LED_CAPSL, true);
+        assert_bit_set(&dev.led_state, LED_CAPSL);
+        dev.update_led_state(LED_CAPSL, false);
+        assert_bit_clear(&dev.led_state, LED_CAPSL);
+    }
+
+    // ---------------------------------------------------------------
+    // 13. abs_info default touchpad
+    // ---------------------------------------------------------------
+    #[test]
+    fn touchpad_abs_x_range() {
+        let dev = InputDevice::new_touchpad(0);
+        let info = dev.abs_info(ABS_X);
+        assert_eq!(info.minimum, 0);
+        assert_eq!(info.maximum, 65_535);
+    }
+
+    #[test]
+    fn touchpad_abs_pressure_max() {
+        let dev = InputDevice::new_touchpad(0);
+        let info = dev.abs_info(ABS_PRESSURE);
+        assert_eq!(info.maximum, 255);
+    }
+
+    #[test]
+    fn touchpad_abs_mt_slot_range() {
+        let dev = InputDevice::new_touchpad(0);
+        let info = dev.abs_info(ABS_MT_SLOT);
+        assert_eq!(info.minimum, 0);
+        assert_eq!(info.maximum, 9);
+    }
+
+    // ---------------------------------------------------------------
+    // 14. set_abs_info overrides default
+    // ---------------------------------------------------------------
+    #[test]
+    fn set_abs_info_override() {
+        let mut dev = InputDevice::new_touchpad(0);
+        let custom = AbsInfo {
+            value: 42,
+            minimum: -100,
+            maximum: 100,
+            fuzz: 1,
+            flat: 2,
+            resolution: 3,
+        };
+        dev.set_abs_info(ABS_X, custom);
+        let info = dev.abs_info(ABS_X);
+        assert_eq!(info.value, 42);
+        assert_eq!(info.minimum, -100);
+        assert_eq!(info.maximum, 100);
+        assert_eq!(info.fuzz, 1);
+        assert_eq!(info.flat, 2);
+        assert_eq!(info.resolution, 3);
+    }
+
+    #[test]
+    fn set_abs_info_does_not_affect_other_axes() {
+        let mut dev = InputDevice::new_touchpad(0);
+        let custom = AbsInfo {
+            value: 0,
+            minimum: -50,
+            maximum: 50,
+            ..AbsInfo::default()
+        };
+        dev.set_abs_info(ABS_X, custom);
+        // ABS_Y should still return the default touchpad range
+        let info_y = dev.abs_info(ABS_Y);
+        assert_eq!(info_y.minimum, 0);
+        assert_eq!(info_y.maximum, 65_535);
+    }
+
+    // ---------------------------------------------------------------
+    // 15. bitmap_from_codes edge cases
+    // ---------------------------------------------------------------
+    #[test]
+    fn bitmap_from_codes_empty_input() {
+        let bm = bitmap_from_codes(&[]);
+        assert!(bm.is_empty());
+    }
+
+    #[test]
+    fn bitmap_from_codes_single_code() {
+        let bm = bitmap_from_codes(&[5u16]);
+        assert_eq!(bm.len(), 1); // (5/8)+1 = 1
+        assert_eq!(bm[0], 1 << 5);
+    }
+
+    #[test]
+    fn bitmap_from_codes_multiple_codes_same_byte() {
+        // REL_X=0, REL_Y=1, REL_WHEEL=8, REL_HWHEEL=6
+        // REL_X and REL_Y are in byte 0; REL_HWHEEL is in byte 0 too; REL_WHEEL is byte 1
+        let bm = bitmap_from_codes(&[REL_X, REL_Y, REL_HWHEEL, REL_WHEEL]);
+        assert_bit_set(&bm, REL_X);
+        assert_bit_set(&bm, REL_Y);
+        assert_bit_set(&bm, REL_WHEEL);
+        assert_bit_set(&bm, REL_HWHEEL);
+        // Byte 0 should have bits 0 (REL_X), 1 (REL_Y), 6 (REL_HWHEEL) set
+        assert_eq!(bm[0], (1 << 0) | (1 << 1) | (1 << 6));
+        // Byte 1 should have bit 0 (REL_WHEEL = 8 → byte 1, bit 0)
+        assert_eq!(bm[1], 1 << 0);
+    }
+}
@@ -263,6 +263,14 @@ impl SchemeSync for FirmwareScheme {
 #[cfg(test)]
 mod tests {
    use super::resolve_key;
+    use super::*;
+    use crate::blob::FirmwareRegistry;
+    use redox_scheme::scheme::SchemeSync;
+    use redox_scheme::{CallerCtx, OpenResult};
+    use std::fs;
+    use std::path::PathBuf;
+    use std::time::{SystemTime, UNIX_EPOCH};
+    use syscall::{EventFlags, MapFlags, MunmapFlags, Stat, MODE_FILE};

    #[test]
    fn accepts_real_firmware_extensions() {
@@ -279,4 +287,364 @@ mod tests {
            Some("amdgpu/psp_13_0_0_sos.bin")
        );
    }
+
+    // --- Helpers ---
+
+    fn test_ctx() -> CallerCtx {
+        CallerCtx {
+            pid: 0,
+            uid: 0,
+            gid: 0,
+            id: unsafe { std::mem::zeroed() },
+        }
+    }
+
+    fn setup_registry() -> (PathBuf, FirmwareRegistry) {
+        let stamp = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        let dir = std::env::temp_dir().join(format!("rbos-fw-scheme-{stamp}"));
+        fs::create_dir_all(&dir).unwrap();
+        fs::write(dir.join("test-blob.bin"), b"Hello, firmware!").unwrap();
+        fs::create_dir_all(dir.join("subdir")).unwrap();
+        fs::write(dir.join("subdir/nested.bin"), b"nested data content").unwrap();
+        let registry = FirmwareRegistry::new(&dir).unwrap();
+        (dir, registry)
+    }
+
+    fn open_test_blob(scheme: &mut FirmwareScheme) -> usize {
+        let ctx = test_ctx();
+        match scheme
+            .openat(SCHEME_ROOT_ID, "test-blob.bin", 0, 0, &ctx)
+            .unwrap()
+        {
+            OpenResult::ThisScheme { number, .. } => number,
+            other => panic!("expected ThisScheme, got {:?}", other),
+        }
+    }
+
+    #[test]
+    fn new_creates_empty_scheme_with_correct_next_id() {
+        let (dir, registry) = setup_registry();
+        let scheme = FirmwareScheme::new(registry);
+        assert!(scheme.handles.is_empty());
+        assert_eq!(scheme.next_id, SCHEME_ROOT_ID + 1);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn openat_valid_key_returns_this_scheme() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let ctx = test_ctx();
+
+        let result = scheme
+            .openat(SCHEME_ROOT_ID, "test-blob.bin", 0, 0, &ctx)
+            .unwrap();
+
+        match result {
+            OpenResult::ThisScheme { number, flags } => {
+                assert_eq!(number, SCHEME_ROOT_ID + 1);
+                assert_eq!(flags, NewFdFlags::empty());
+            }
+            other => panic!("expected ThisScheme, got {:?}", other),
+        }
+        assert_eq!(scheme.handles.len(), 1);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn openat_missing_key_returns_enoent() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let ctx = test_ctx();
+
+        let err = scheme
+            .openat(SCHEME_ROOT_ID, "nonexistent.bin", 0, 0, &ctx)
+            .unwrap_err();
+        assert_eq!(err.errno, ENOENT);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn openat_rejects_path_traversal() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let ctx = test_ctx();
+
+        let err = scheme
+            .openat(SCHEME_ROOT_ID, "../etc/passwd", 0, 0, &ctx)
+            .unwrap_err();
+        assert_eq!(err.errno, EISDIR);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn openat_empty_path_returns_eisdir() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let ctx = test_ctx();
+
+        let err = scheme
+            .openat(SCHEME_ROOT_ID, "", 0, 0, &ctx)
+            .unwrap_err();
+        assert_eq!(err.errno, EISDIR);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn openat_wrong_dirfd_returns_eacces() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let ctx = test_ctx();
+
+        let err = scheme
+            .openat(999, "test-blob.bin", 0, 0, &ctx)
+            .unwrap_err();
+        assert_eq!(err.errno, EACCES);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn read_at_offset_zero() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let mut buf = [0u8; 64];
+        let n = scheme.read(id, &mut buf, 0, 0, &ctx).unwrap();
+        assert_eq!(n, 16);
+        assert_eq!(&buf[..16], b"Hello, firmware!");
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn read_at_nonzero_offset() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let mut buf = [0u8; 64];
+        let n = scheme.read(id, &mut buf, 7, 0, &ctx).unwrap();
+        assert_eq!(n, 9);
+        assert_eq!(&buf[..9], b"firmware!");
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn read_past_end_returns_zero() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let mut buf = [0u8; 64];
+        let n = scheme.read(id, &mut buf, 16, 0, &ctx).unwrap();
+        assert_eq!(n, 0);
+        let n2 = scheme.read(id, &mut buf, 1000, 0, &ctx).unwrap();
+        assert_eq!(n2, 0);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn fstat_reports_correct_size_and_mode() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let mut stat: Stat = unsafe { std::mem::zeroed() };
+        scheme.fstat(id, &mut stat, &ctx).unwrap();
+        assert_eq!(stat.st_mode, MODE_FILE | 0o444);
+        assert_eq!(stat.st_size, 16);
+        assert_eq!(stat.st_blksize, 4096);
+        assert!(stat.st_blocks > 0);
+        assert_eq!(stat.st_nlink, 1);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn fsize_returns_correct_length() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let size = scheme.fsize(id, &ctx).unwrap();
+        assert_eq!(size, 16);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn write_returns_erofs() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let err = scheme.write(id, b"test", 0, 0, &ctx).unwrap_err();
+        assert_eq!(err.errno, EROFS);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn ftruncate_returns_erofs() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let err = scheme.ftruncate(id, 0, &ctx).unwrap_err();
+        assert_eq!(err.errno, EROFS);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn mmap_prep_returns_pointer_and_increments_count() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let ptr = scheme
+            .mmap_prep(id, 0, 16, MapFlags::empty(), &ctx)
+            .unwrap();
+        assert_ne!(ptr, 0);
+
+        let handle = scheme.handles.get(&id).unwrap();
+        assert_eq!(handle.map_count, 1);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn mmap_prep_rejects_offset_beyond_data() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let err = scheme
+            .mmap_prep(id, 17, 1, MapFlags::empty(), &ctx)
+            .unwrap_err();
+        assert_eq!(err.errno, EINVAL);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn mmap_prep_rejects_offset_plus_size_beyond_data() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let err = scheme
+            .mmap_prep(id, 8, 16, MapFlags::empty(), &ctx)
+            .unwrap_err();
+        assert_eq!(err.errno, EINVAL);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn munmap_decrements_count_without_removing_handle() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        scheme
+            .mmap_prep(id, 0, 16, MapFlags::empty(), &ctx)
+            .unwrap();
+        assert_eq!(scheme.handles.get(&id).unwrap().map_count, 1);
+
+        scheme
+            .munmap(id, 0, 16, MunmapFlags::empty(), &ctx)
+            .unwrap();
+
+        assert!(scheme.handles.contains_key(&id));
+        let handle = scheme.handles.get(&id).unwrap();
+        assert_eq!(handle.map_count, 0);
+        assert!(!handle.closed);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn on_close_keeps_handle_when_mapped() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        scheme
+            .mmap_prep(id, 0, 16, MapFlags::empty(), &ctx)
+            .unwrap();
+
+        scheme.on_close(id);
+
+        assert!(scheme.handles.contains_key(&id));
+        let handle = scheme.handles.get(&id).unwrap();
+        assert!(handle.closed);
+        assert_eq!(handle.map_count, 1);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn on_close_then_munmap_removes_handle() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        scheme
+            .mmap_prep(id, 0, 16, MapFlags::empty(), &ctx)
+            .unwrap();
+
+        scheme.on_close(id);
+        assert!(scheme.handles.contains_key(&id));
+
+        scheme
+            .munmap(id, 0, 16, MunmapFlags::empty(), &ctx)
+            .unwrap();
+        assert!(!scheme.handles.contains_key(&id));
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn fsync_returns_ok() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        scheme.fsync(id, &ctx).unwrap();
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn fcntl_returns_ok_zero() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let result = scheme.fcntl(id, 0, 0, &ctx).unwrap();
+        assert_eq!(result, 0);
+        let _ = fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn fevent_returns_empty_flags() {
+        let (dir, registry) = setup_registry();
+        let mut scheme = FirmwareScheme::new(registry);
+        let id = open_test_blob(&mut scheme);
+        let ctx = test_ctx();
+
+        let flags = scheme
+            .fevent(id, EventFlags::empty(), &ctx)
+            .unwrap();
+        assert_eq!(flags, EventFlags::empty());
+        let _ = fs::remove_dir_all(&dir);
+    }
 }
@@ -212,7 +212,7 @@ fn format_device_name(

 #[cfg(test)]
 mod tests {
-    use super::classify_pci_device;
+    use super::{DeviceInfo, InputKind, Subsystem, classify_pci_device, device_properties, format_device_info, format_uevent_info};

    #[test]
    fn classify_pci_device_uses_shared_location_format() {
@@ -227,6 +227,253 @@ mod tests {

        assert_eq!(device.id_path(), "pci-0000:02:00.0");
    }
+
+    #[test]
+    fn new_platform_input_has_correct_defaults() {
+        let dev = DeviceInfo::new_platform_input(
+            "test-kbd",
+            "/devices/platform/keyboard0",
+            InputKind::Keyboard,
+            "",
+            "",
+        );
+        assert!(!dev.is_pci);
+        assert_eq!(dev.subsystem, Subsystem::Input);
+        assert_eq!(dev.input_kind, Some(InputKind::Keyboard));
+        assert!(dev.devnode.is_empty());
+        assert!(dev.scheme_target.is_empty());
+        assert!(dev.symlinks.is_empty());
+        assert_eq!(dev.bus, 0);
+        assert_eq!(dev.dev, 0);
+        assert_eq!(dev.func, 0);
+        assert_eq!(dev.vendor_id, 0);
+        assert_eq!(dev.device_id, 0);
+    }
+
+    #[test]
+    fn set_node_metadata_sets_fields_correctly() {
+        let mut dev = DeviceInfo::new_platform_input(
+            "test-mouse",
+            "/devices/platform/mouse0",
+            InputKind::Mouse,
+            "",
+            "",
+        );
+        dev.set_node_metadata(
+            "/dev/input/mouse0",
+            "input:mouse0",
+            vec!["/dev/input/by-path/platform-mouse0".to_string()],
+        );
+        assert_eq!(dev.devnode, "/dev/input/mouse0");
+        assert_eq!(dev.scheme_target, "input:mouse0");
+        assert_eq!(dev.symlinks.len(), 1);
+        assert_eq!(dev.symlinks[0], "/dev/input/by-path/platform-mouse0");
+    }
+
+    #[test]
+    fn subsystem_name_maps_all_variants() {
+        let cases: Vec<(Subsystem, &'static str)> = vec![
+            (Subsystem::Gpu, "drm"),
+            (Subsystem::Network, "net"),
+            (Subsystem::Storage, "block"),
+            (Subsystem::Audio, "sound"),
+            (Subsystem::Usb, "usb"),
+            (Subsystem::Input, "input"),
+            (Subsystem::Unknown, "unknown"),
+        ];
+        for (subsys, expected) in cases {
+            let mut dev =
+                DeviceInfo::new_platform_input("x", "/devices/x", InputKind::Generic, "", "");
+            dev.subsystem = subsys;
+            assert_eq!(dev.subsystem_name(), expected, "failed for {:?}", subsys);
+        }
+    }
+
+    #[test]
+    fn id_path_pci_device() {
+        let dev = DeviceInfo {
+            is_pci: true,
+            bus: 0x02,
+            dev: 0x00,
+            func: 0x0,
+            vendor_id: 0x1002,
+            device_id: 0x67df,
+            class_code: 0x03,
+            subclass: 0x00,
+            subsystem: Subsystem::Gpu,
+            input_kind: None,
+            name: "Test GPU".to_string(),
+            devpath: "/devices/pci/0000:02:00.0".to_string(),
+            devnode: String::new(),
+            scheme_target: String::new(),
+            symlinks: vec![],
+        };
+        assert_eq!(dev.id_path(), "pci-0000:02:00.0");
+    }
+
+    #[test]
+    fn id_path_platform_device() {
+        let dev = DeviceInfo::new_platform_input(
+            "keyboard0",
+            "/devices/platform/keyboard0",
+            InputKind::Keyboard,
+            "",
+            "",
+        );
+        assert_eq!(dev.id_path(), "platform-keyboard0");
+    }
+
+    #[test]
+    fn is_input_keyboard_true_only_for_keyboard() {
+        let kb = DeviceInfo::new_platform_input("kb", "/devices/x", InputKind::Keyboard, "", "");
+        assert!(kb.is_input_keyboard());
+        assert!(!kb.is_input_mouse());
+
+        let mouse = DeviceInfo::new_platform_input("ms", "/devices/x", InputKind::Mouse, "", "");
+        assert!(!mouse.is_input_keyboard());
+
+        let generic =
+            DeviceInfo::new_platform_input("gen", "/devices/x", InputKind::Generic, "", "");
+        assert!(!generic.is_input_keyboard());
+    }
+
+    #[test]
+    fn is_input_mouse_true_only_for_mouse() {
+        let mouse = DeviceInfo::new_platform_input("ms", "/devices/x", InputKind::Mouse, "", "");
+        assert!(mouse.is_input_mouse());
+        assert!(!mouse.is_input_keyboard());
+
+        let kb = DeviceInfo::new_platform_input("kb", "/devices/x", InputKind::Keyboard, "", "");
+        assert!(!kb.is_input_mouse());
+
+        let generic =
+            DeviceInfo::new_platform_input("gen", "/devices/x", InputKind::Generic, "", "");
+        assert!(!generic.is_input_mouse());
+    }
+
+    #[test]
+    fn device_properties_gpu_pci_contains_key_fields() {
+        let dev = DeviceInfo {
+            is_pci: true,
+            bus: 0x02,
+            dev: 0x00,
+            func: 0x0,
+            vendor_id: 0x1002,
+            device_id: 0x67df,
+            class_code: 0x03,
+            subclass: 0x00,
+            subsystem: Subsystem::Gpu,
+            input_kind: None,
+            name: "AMD RX 580 [1002:67df]".to_string(),
+            devpath: "/devices/pci/0000:02:00.0".to_string(),
+            devnode: "/dev/dri/card0".to_string(),
+            scheme_target: "display:display".to_string(),
+            symlinks: vec![],
+        };
+        let props = device_properties(&dev);
+        let prop_map: std::collections::HashMap<&str, &str> = props
+            .iter()
+            .map(|(k, v)| (k.as_str(), v.as_str()))
+            .collect();
+
+        assert_eq!(prop_map.get("SUBSYSTEM").copied(), Some("drm"));
+        assert_eq!(prop_map.get("PCI_VENDOR_ID").copied(), Some("0x1002"));
+        assert_eq!(prop_map.get("PCI_DEVICE_ID").copied(), Some("0x67df"));
+        assert_eq!(prop_map.get("PCI_CLASS").copied(), Some("0x0300"));
+        assert_eq!(prop_map.get("DEVNAME").copied(), Some("/dev/dri/card0"));
+    }
+
+    #[test]
+    fn device_properties_input_keyboard_has_input_flags() {
+        let dev = DeviceInfo::new_platform_input(
+            "keyboard0",
+            "/devices/platform/keyboard0",
+            InputKind::Keyboard,
+            "/dev/input/event0",
+            "input:keyboard0",
+        );
+        let props = device_properties(&dev);
+        let prop_map: std::collections::HashMap<&str, &str> = props
+            .iter()
+            .map(|(k, v)| (k.as_str(), v.as_str()))
+            .collect();
+
+        assert_eq!(prop_map.get("ID_INPUT").copied(), Some("1"));
+        assert_eq!(prop_map.get("ID_INPUT_KEYBOARD").copied(), Some("1"));
+        assert!(!prop_map.contains_key("ID_INPUT_MOUSE"));
+    }
+
+    #[test]
+    fn device_properties_input_mouse_has_input_flags() {
+        let dev = DeviceInfo::new_platform_input(
+            "mouse0",
+            "/devices/platform/mouse0",
+            InputKind::Mouse,
+            "/dev/input/mouse0",
+            "input:mouse0",
+        );
+        let props = device_properties(&dev);
+        let prop_map: std::collections::HashMap<&str, &str> = props
+            .iter()
+            .map(|(k, v)| (k.as_str(), v.as_str()))
+            .collect();
+
+        assert_eq!(prop_map.get("ID_INPUT").copied(), Some("1"));
+        assert_eq!(prop_map.get("ID_INPUT_MOUSE").copied(), Some("1"));
+        assert!(!prop_map.contains_key("ID_INPUT_KEYBOARD"));
+    }
+
+    #[test]
+    fn format_device_info_structure() {
+        let dev = DeviceInfo {
+            is_pci: true,
+            bus: 0x02,
+            dev: 0x00,
+            func: 0x0,
+            vendor_id: 0x8086,
+            device_id: 0x1234,
+            class_code: 0x03,
+            subclass: 0x00,
+            subsystem: Subsystem::Gpu,
+            input_kind: None,
+            name: "Intel GPU".to_string(),
+            devpath: "/devices/pci/0000:02:00.0".to_string(),
+            devnode: "/dev/dri/card0".to_string(),
+            scheme_target: "display:display".to_string(),
+            symlinks: vec!["/dev/dri/by-path/pci-0000:02:00.0-card".to_string()],
+        };
+        let info = format_device_info(&dev);
+        assert!(info.starts_with("P=/devices/pci/0000:02:00.0\n"));
+        assert!(info.contains("E=SUBSYSTEM=drm\n"));
+        assert!(info.contains("S=dev/dri/by-path/pci-0000:02:00.0-card\n"));
+    }
+
+    #[test]
+    fn format_uevent_info_starts_with_action_and_has_props() {
+        let dev = DeviceInfo::new_platform_input(
+            "keyboard0",
+            "/devices/platform/keyboard0",
+            InputKind::Keyboard,
+            "/dev/input/event0",
+            "input:keyboard0",
+        );
+        let uevent = format_uevent_info(&dev);
+        assert!(uevent.starts_with("ACTION=add\n"));
+        assert!(uevent.contains("SUBSYSTEM=input\n"));
+        assert!(uevent.contains("DEVPATH=/devices/platform/keyboard0\n"));
+    }
+
+    #[test]
+    fn classify_pci_device_with_no_pci_config_still_produces_pci_device() {
+        let dev = classify_pci_device(0x00, 0x1f, 0x2);
+        assert!(dev.is_pci);
+        assert_eq!(dev.bus, 0x00);
+        assert_eq!(dev.dev, 0x1f);
+        assert_eq!(dev.func, 0x2);
+        // Without real PCI config, read_pci_config returns 0xFFFF
+        assert_eq!(dev.vendor_id, 0xFFFF);
+        assert_eq!(dev.device_id, 0xFFFF);
+    }
 }

 pub fn device_properties(dev: &DeviceInfo) -> Vec<(String, String)> {