updater: Add "write_value()" function.
write_value(value, filename) writes 'value' to 'filename'. It can be
used to tune device settings when applying an OTA package. For example,
write_value("960000", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq").
Bug: 32463933
Test: recovery_component_test passes.
Test: Apply an OTA package that contains a call to write_value(), and
check the result.
Change-Id: Ib009ecb8a45a94353f10c59e2383fe1f49796e35
diff --git a/updater/install.cpp b/updater/install.cpp
index b885f86..da68420 100644
--- a/updater/install.cpp
+++ b/updater/install.cpp
@@ -39,11 +39,12 @@
#include <string>
#include <vector>
-#include <android-base/parseint.h>
+#include <android-base/file.h>
#include <android-base/parsedouble.h>
+#include <android-base/parseint.h>
#include <android-base/properties.h>
-#include <android-base/strings.h>
#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
#include <cutils/android_reboot.h>
#include <ext4_utils/make_ext4fs.h>
#include <ext4_utils/wipe.h>
@@ -861,7 +862,6 @@
return StringValue(value);
}
-
// file_getprop(file, key)
//
// interprets 'file' as a getprop-style file (key=value pairs, one
@@ -1155,6 +1155,33 @@
return v;
}
+// write_value(value, filename)
+// Writes 'value' to 'filename'.
+// Example: write_value("960000", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq")
+Value* WriteValueFn(const char* name, State* state, int argc, Expr* argv[]) {
+ if (argc != 2) {
+ return ErrorAbort(state, kArgsParsingFailure, "%s() expects 2 args, got %d", name, argc);
+ }
+
+ std::vector<std::string> args;
+ if (!ReadArgs(state, 2, argv, &args)) {
+ return ErrorAbort(state, kArgsParsingFailure, "%s(): Failed to parse the argument(s)", name);
+ }
+
+ const std::string& filename = args[1];
+ if (filename.empty()) {
+ return ErrorAbort(state, kArgsParsingFailure, "%s(): Filename cannot be empty", name);
+ }
+
+ const std::string& value = args[0];
+ if (!android::base::WriteStringToFile(value, filename)) {
+ printf("%s: Failed to write to \"%s\": %s\n", name, filename.c_str(), strerror(errno));
+ return StringValue("");
+ } else {
+ return StringValue("t");
+ }
+}
+
// Immediately reboot the device. Recovery is not finished normally,
// so if you reboot into recovery it will re-start applying the
// current package (because nothing has cleared the copy of the
@@ -1363,6 +1390,7 @@
RegisterFunction("read_file", ReadFileFn);
RegisterFunction("sha1_check", Sha1CheckFn);
RegisterFunction("rename", RenameFn);
+ RegisterFunction("write_value", WriteValueFn);
RegisterFunction("wipe_cache", WipeCacheFn);