feat: device subsystem rework

[lunaix-os.git] / lunaix-os / hal / char / devnull.c

diff --git a/lunaix-os/hal/char/devnull.c b/lunaix-os/hal/char/devnull.c
new file mode 100644 (file)
index 0000000..12bd007
--- /dev/null
+++ b/lunaix-os/hal/char/devnull.c
@@ -0,0 +1,49 @@
+#include <lunaix/device.h>
+#include <lunaix/mm/page.h>
+
+static int
+__null_wr_pg(struct device* dev, void* buf, size_t offset)
+{
+    // do nothing
+    return PG_SIZE;
+}
+
+static int
+__null_wr(struct device* dev, void* buf, size_t offset, size_t len)
+{
+    // do nothing
+    return len;
+}
+
+static int
+__null_rd_pg(struct device* dev, void* buf, size_t offset)
+{
+    // do nothing
+    return 0;
+}
+
+static int
+__null_rd(struct device* dev, void* buf, size_t offset, size_t len)
+{
+    // do nothing
+    return 0;
+}
+
+static int
+pdev_nulldev_init(struct device_def*)
+{
+    struct device* devnull = device_addseq(NULL, NULL, "null");
+    devnull->ops.write_page = __null_wr_pg;
+    devnull->ops.write = __null_wr;
+    devnull->ops.read_page = __null_rd_pg;
+    devnull->ops.read = __null_rd;
+
+    return 0;
+}
+
+static struct device_def devnull_def = {
+    .name = "null",
+    .class = DEVCLASS(DEVIF_NON, DEVFN_PSEUDO, 0, 0),
+    .init = pdev_nulldev_init
+};
+EXPORT_DEVICE(nulldev, &devnull_def, load_earlystage);