VFS mountpoint backing device system

kernel/device/ramdrv.c

@@ -0,0 +1,109 @@
+#include <device/device.h>
+#include <device/ramdrv.h>
+#include <libk/std.h>
+#include <libk/string.h>
+#include <m/status.h>
+#include <m/xdrv_device.h>
+#include <mm/liballoc.h>
+
+bool ramdrv_init (struct device* device, void* arg) {
+  struct ramdrv_init* init = arg;
+
+  struct ramdrv* ramdrv = malloc (sizeof (*ramdrv));
+
+  if (ramdrv == NULL)
+    return false;
+
+  ramdrv->total_size = init->total_size;
+  ramdrv->sector_size = init->sector_size;
+
+  if (init->buffer == NULL) {
+    ramdrv->buffer = malloc (init->total_size);
+
+    if (ramdrv->buffer == NULL) {
+      free (ramdrv);
+      return false;
+    }
+
+    ramdrv->managed = false;
+  } else {
+    ramdrv->buffer = init->buffer;
+    ramdrv->managed = true;
+  }
+
+  device->udata = ramdrv;
+
+  return true;
+}
+
+void ramdrv_fini (struct device* device) {
+  struct ramdrv* ramdrv = device->udata;
+
+  if (!ramdrv->managed)
+    free (ramdrv);
+}
+
+int ramdrv_get_device_type (struct device* device, struct device_op_ctx* op_ctx, void* a1, void* a2,
+                            void* a3, void* a4) {
+  (void)device, (void)a2, (void)a3, (void)a4, (void)op_ctx;
+
+  if (a1 == NULL)
+    return -ST_BAD_ADDRESS_SPACE;
+
+  int* device_type = (int*)a1;
+
+  *device_type = XDRV_TYPE_RAMDRV;
+
+  return ST_OK;
+}
+
+int ramdrv_get_size (struct device* device, struct device_op_ctx* op_ctx, void* a1, void* a2,
+                     void* a3, void* a4) {
+  (void)a2, (void)a3, (void)a4, (void)op_ctx;
+
+  if (a1 == NULL)
+    return -ST_BAD_ADDRESS_SPACE;
+
+  size_t* size = (size_t*)a1;
+
+  struct ramdrv* ramdrv = device->udata;
+
+  *size = ramdrv->total_size;
+
+  return ST_OK;
+}
+
+int ramdrv_get_sector_size (struct device* device, struct device_op_ctx* op_ctx, void* a1, void* a2,
+                            void* a3, void* a4) {
+  (void)a2, (void)a3, (void)a4, (void)op_ctx;
+
+  if (a1 == NULL)
+    return -ST_BAD_ADDRESS_SPACE;
+
+  size_t* secsize = (size_t*)a1;
+
+  struct ramdrv* ramdrv = device->udata;
+
+  *secsize = ramdrv->sector_size;
+
+  return ST_OK;
+}
+
+int ramdrv_read (struct device* device, struct device_op_ctx* op_ctx, void* a1, void* a2, void* a3,
+                 void* a4) {
+  if (a1 == NULL || a2 == NULL || a3 == NULL)
+    return -ST_BAD_ADDRESS_SPACE;
+
+  size_t pos = *(size_t*)a1;
+  size_t size = *(size_t*)a2;
+  uint8_t* buffer = a3;
+
+  struct ramdrv* ramdrv = device->udata;
+
+  if (pos + size > ramdrv->total_size)
+    return -ST_OOB_ERROR;
+
+  memcpy (buffer, (void*)(((uintptr_t)ramdrv->buffer) + pos), size);
+
+  return ST_OK;
+}