1 files changed, 58 insertions, 0 deletions
diff --git a/src/hibernate-resume/hibernate-resume.c b/src/hibernate-resume/hibernate-resume.c
new file mode 100644
index 0000000..1c7d917
--- /dev/null
+++ b/src/hibernate-resume/hibernate-resume.c
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stdio.h>
+#include <sys/stat.h>
+
+#include "alloc-util.h"
+#include "devnum-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "util.h"
+
+int main(int argc, char *argv[]) {
+        struct stat st;
+        const char *device;
+        int r;
+
+        if (argc != 2) {
+                log_error("This program expects one argument.");
+                return EXIT_FAILURE;
+        }
+
+        log_setup();
+
+        umask(0022);
+
+        /* Refuse to run unless we are in an initrd() */
+        if (!in_initrd())
+                return EXIT_SUCCESS;
+
+        device = argv[1];
+
+        if (stat(device, &st) < 0) {
+                log_error_errno(errno, "Failed to stat '%s': %m", device);
+                return EXIT_FAILURE;
+        }
+
+        if (!S_ISBLK(st.st_mode)) {
+                log_error("Resume device '%s' is not a block device.", device);
+                return EXIT_FAILURE;
+        }
+
+        r = write_string_file("/sys/power/resume", FORMAT_DEVNUM(st.st_rdev), WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0) {
+                log_error_errno(r, "Failed to write '" DEVNUM_FORMAT_STR "' to /sys/power/resume: %m", DEVNUM_FORMAT_VAL(st.st_rdev));
+                return EXIT_FAILURE;
+        }
+
+        /*
+         * The write above shall not return.
+         *
+         * However, failed resume is a normal condition (may mean that there is
+         * no hibernation image).
+         */
+
+        log_info("Could not resume from '%s' (" DEVNUM_FORMAT_STR ").", device, DEVNUM_FORMAT_VAL(st.st_rdev));
+        return EXIT_SUCCESS;
+}