1 files changed, 106 insertions, 0 deletions
diff --git a/usr/kinit/resume/resumelib.c b/usr/kinit/resume/resumelib.c
new file mode 100644
index 0000000..03e596a
--- /dev/null
+++ b/usr/kinit/resume/resumelib.c
@@ -0,0 +1,106 @@
+/*
+ * Handle resume from suspend-to-disk
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+
+#include "kinit.h"
+#include "do_mounts.h"
+#include "resume.h"
+
+#ifndef CONFIG_PM_STD_PARTITION
+# define CONFIG_PM_STD_PARTITION ""
+#endif
+
+int do_resume(int argc, char *argv[])
+{
+	const char *resume_file = CONFIG_PM_STD_PARTITION;
+	const char *resume_arg;
+	unsigned long long resume_offset;
+
+	resume_arg = get_arg(argc, argv, "resume=");
+	resume_file = resume_arg ? resume_arg : resume_file;
+	/* No resume device specified */
+	if (!resume_file[0])
+		return 0;
+
+	resume_arg = get_arg(argc, argv, "resume_offset=");
+	resume_offset = resume_arg ? strtoull(resume_arg, NULL, 0) : 0ULL;
+
+	/* Fix: we either should consider reverting the device back to
+	   ordinary swap, or (better) put that code into swapon */
+	/* Noresume requested */
+	if (get_flag(argc, argv, "noresume"))
+		return 0;
+	return resume(resume_file, resume_offset);
+}
+
+int resume(const char *resume_file, unsigned long long resume_offset)
+{
+	dev_t resume_device;
+	int attr_fd = -1;
+	char attr_value[64];
+	int len;
+
+	resume_device = name_to_dev_t(resume_file);
+
+	if (major(resume_device) == 0) {
+		fprintf(stderr, "Invalid resume device: %s\n", resume_file);
+		goto failure;
+	}
+
+	if ((attr_fd = open("/sys/power/resume_offset", O_WRONLY)) < 0)
+		goto fail_offset;
+
+	len = snprintf(attr_value, sizeof attr_value,
+		       "%llu",
+		       resume_offset);
+
+	/* This should never happen */
+	if (len >= sizeof attr_value)
+		goto fail_offset;
+
+	if (write(attr_fd, attr_value, len) != len)
+		goto fail_offset;
+
+	close(attr_fd);
+
+	if ((attr_fd = open("/sys/power/resume", O_WRONLY)) < 0)
+		goto fail_r;
+
+	len = snprintf(attr_value, sizeof attr_value,
+		       "%u:%u",
+		       major(resume_device), minor(resume_device));
+
+	/* This should never happen */
+	if (len >= sizeof attr_value)
+		goto fail_r;
+
+	dprintf("kinit: trying to resume from %s\n", resume_file);
+
+	if (write(attr_fd, attr_value, len) != len)
+		goto fail_r;
+
+	/* Okay, what are we still doing alive... */
+failure:
+	if (attr_fd >= 0)
+		close(attr_fd);
+	dprintf("kinit: No resume image, doing normal boot...\n");
+	return -1;
+
+fail_offset:
+	fprintf(stderr, "Cannot write /sys/power/resume_offset "
+			"(no software suspend kernel support, or old kernel version?)\n");
+	goto failure;
+
+fail_r:
+	fprintf(stderr, "Cannot write /sys/power/resume "
+			"(no software suspend kernel support?)\n");
+	goto failure;
+}