First pass of save

src/dusklinux/CMakeLists.txt

@@ -16,5 +16,7 @@ add_subdirectory(input)
 if(DUSK_NETWORK)
   add_subdirectory(network)
 endif()
+add_subdirectory(save)
 add_subdirectory(system)
-add_subdirectory(time)
+add_subdirectory(time)
+add_subdirectory(util)

src/dusklinux/save/CMakeLists.txt

@@ -0,0 +1,9 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    savedevicelinux.c
+)

src/dusklinux/save/savedevicelinux.c

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "save/savedevice.h"
+#include "save/savedevicelinux.h"
+#include "assert/assert.h"
+#include "util/mkdirp.h"
+
+errorret_t saveDeviceLinuxInit(savedevice_t *device) {
+  assertNotNull(device, "device cannot be null");
+  
+  device->state = SAVE_DEVICE_STATE_UNKNOWN;
+
+  errorOk();
+}
+
+errorret_t saveDeviceLinuxUpdate(savedevice_t *device) {
+  assertNotNull(device, "device cannot be null");
+  assertIsMainThread("Invalid thread");
+  errorOk();
+}
+
+void saveDeviceLinuxCheckAvailability(savedevice_t *device) {
+  assertNotNull(device, "device cannot be null");
+  assertIsMainThread("Invalid thread");
+  assertTrue(
+    device->state == SAVE_DEVICE_STATE_CHECKING_AVAILABILITY,
+    "Device state incorrect?"
+  );
+  
+  // Mkdirp the save directory.
+  int mkdirpResult = mkdirp(SAVE_DEVICE_LINUX_DIRECTORY, 0700);
+  if(mkdirpResult != 0) {
+    device->state = SAVE_DEVICE_STATE_UNAVAILABLE;
+    device->reasonKey = "save.linux.mkdirp_failed";
+    return saveDeviceFireCallback(device);
+  }
+
+  // The save device is available.
+  device->state = SAVE_DEVICE_STATE_AVAILABLE;
+  device->reasonKey = NULL;
+  saveDeviceFireCallback(device);
+}
+
+errorret_t saveDeviceLinuxDispose(savedevice_t *device) {
+  errorOk();
+}

src/dusklinux/save/savedevicelinux.h

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "error/error.h"
+
+#define SAVE_DEVICE_LINUX_DIRECTORY "~/.dusk/saves"
+#define SAVE_DEVICE_LINUX_FILE "~/.dusk/saves/save.dat"
+
+typedef struct {
+  void *nothing;
+} savedeviceplatform_t;
+
+typedef struct savedevice_s savedevice_t;
+
+/**
+ * Initializes the save device platform.
+ * 
+ * @param device The save device platform to initialize.
+ * @return Error state if any.
+ */
+errorret_t saveDeviceLinuxInit(savedevice_t *device);
+
+/**
+ * Updates the save device platform.
+ * 
+ * @param device The save device platform to update.
+ * @return Error state if any.
+ */
+errorret_t saveDeviceLinuxUpdate(savedevice_t *device);
+
+/**
+ * Requests the device to check its availability, this will call the callback
+ * whence completed.
+ * 
+ * @param device The save device platform to check availability.
+ */
+void saveDeviceLinuxCheckAvailability(savedevice_t *device);
+
+/**
+ * Disposes of the save device platform.
+ * 
+ * @param device The save device platform to dispose.
+ * @return Error state if any.
+ */
+errorret_t saveDeviceLinuxDispose(savedevice_t *device);

src/dusklinux/save/savedeviceplatform.h

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "savedevicelinux.h"
+
+#define SAVE_DEVICE_COUNT 1
+
+#define saveDevicePlatformInit saveDeviceLinuxInit
+#define saveDevicePlatformUpdate saveDeviceLinuxUpdate
+#define saveDeviceCheckAvailabilityPlatform saveDeviceLinuxCheckAvailability
+#define saveDevicePlatformDispose saveDeviceLinuxDispose

src/dusklinux/util/CMakeLists.txt

@@ -0,0 +1,9 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    mkdirp.c
+)

src/dusklinux/util/mkdirp.c

@@ -0,0 +1,38 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "util/mkdirp.h"
+#include "util/string.h"
+#include "assert/assert.h"
+#include <sys/stat.h>
+#include <limits.h>
+
+int_t mkdirp(const char_t *path, const int_t mode) {
+  assertNotNull(path, "path cannot be null");
+  assertStrLenMax(path, PATH_MAX, "path is too long");
+
+  char_t buffer[PATH_MAX];
+  stringCopy(buffer, path, sizeof(buffer) - 1);
+
+  size_t len = strlen(buffer);
+  if(len == 0) return -1;
+
+  // Strip a trailing slash so the loop below doesn't try to create the same
+  // directory twice.
+  if(buffer[len - 1] == '/') buffer[len - 1] = '\0';
+
+  for(char_t *p = buffer + 1; *p != '\0'; p++) {
+    if(*p != '/') continue;
+
+    *p = '\0';
+    if(mkdir(buffer, mode) != 0 && errno != EEXIST) return -1;
+    *p = '/';
+  }
+
+  if(mkdir(buffer, mode) != 0 && errno != EEXIST) return -1;
+  return 0;
+}

src/dusklinux/util/mkdirp.h

@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "dusk.h"
+
+/**
+ * Recursively creates a directory and any missing parent directories, similar
+ * to the shell command `mkdir -p`. If the directory already exists, this is
+ * considered a success.
+ *
+ * @param path The path of the directory to create.
+ * @param mode The permissions to create the directories with.
+ * @return 0 on success, -1 on failure (errno will be set).
+ */
+int_t mkdirp(const char_t *path, const int_t mode);