Add fbdev for getting framebuffer information

kernel/dev/fbdev.c

@@ -0,0 +1,29 @@
+#include <stdint.h>
+#include <stddef.h>
+#include "fbdev.h"
+#include "dev.h"
+#include "sysdefs/devctl.h"
+#include "hshtb.h"
+#include "spinlock/spinlock.h"
+#include "util/util.h"
+#include "hal/hal.h"
+#include "bootinfo/bootinfo.h"
+#include "errors.h"
+
+int32_t fbdev_getinfo(uint8_t *buffer, size_t len, void *extra) {
+  FbDevGetInfo info = {
+    .w = BOOT_INFO.fb->width,
+    .h = BOOT_INFO.fb->height,
+    .margin = 20,
+    .fontw = 8,
+    .fonth = 16,
+  };
+  hal_memcpy(buffer, &info, sizeof(info));
+  return E_OK;
+}
+
+void fbdev_init(void) {
+  Dev *fbdev;
+  HSHTB_ALLOC(DEVTABLE.devs, ident, "fbdev", fbdev);
+  fbdev->fns[DEV_FBDEV_GETINFO] = &fbdev_getinfo;
+}