4 files changed, 172 insertions, 0 deletions
diff --git a/usr/kinit/resume/Kbuild b/usr/kinit/resume/Kbuild
new file mode 100644
index 0000000..c804a85
--- /dev/null
+++ b/usr/kinit/resume/Kbuild
@@ -0,0 +1,34 @@
+#
+# Kbuild file for resume
+#
+
+static-y := static/resume
+shared-y := shared/resume
+
+# common .o files
+objs := resume.o resumelib.o
+
+# TODO - do we want a stripped version
+# TODO - do we want the static.g + shared.g directories?
+
+# Create lib.a with all object files (used by kinit)
+lib-y := $(objs)
+
+# Additional include paths files
+KLIBCCFLAGS += -I$(srctree)/$(src)/..
+
+# .o files used to built executables
+static/resume-y   := $(objs)
+static/resume-lib := ../lib.a
+shared/resume-y   := $(objs)
+shared/resume-lib := ../lib.a
+
+# Cleaning
+clean-dirs := static shared
+
+# install binary
+ifdef KLIBCSHAREDFLAGS
+install-y := $(shared-y)
+else
+install-y := $(static-y)
+endif
diff --git a/usr/kinit/resume/resume.c b/usr/kinit/resume/resume.c
new file mode 100644
index 0000000..2138078
--- /dev/null
+++ b/usr/kinit/resume/resume.c
@@ -0,0 +1,25 @@
+/*
+ * Handle resume from suspend-to-disk
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "resume.h"
+
+char *progname;
+
+static __noreturn usage(void)
+{
+	fprintf(stderr, "Usage: %s /dev/<resumedevice> [offset]\n", progname);
+	exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+	progname = argv[0];
+	if (argc < 2 || argc > 3)
+		usage();
+
+	return resume(argv[1], (argc > 2) ? strtoull(argv[2], NULL, 0) : 0ULL);
+}
diff --git a/usr/kinit/resume/resume.h b/usr/kinit/resume/resume.h
new file mode 100644
index 0000000..5fb929f
--- /dev/null
+++ b/usr/kinit/resume/resume.h
@@ -0,0 +1,7 @@
+#ifndef RESUME_H
+#define RESUME_H
+
+int do_resume(int argc, char *argv[]);
+int resume(const char *resume_file, unsigned long long resume_offset);
+
+#endif /* RESUME_H */
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;
+}