/android_device_planet_cosmo

Primary LanguageMakefile

This is a complete disaster, but at least I learned some things about Android internals I guess?

Basic TWRP build for the Cosmo Communicator. This uses the kernel and the TrustKernel system files from the stock firmware to allow the userdata partition to be decrypted and accessed.

Caveats

  • Most features are untested (especially SD card and external storage)
  • Doesn't seem to work with Planet's OTA zips
  • Will require change to BoardConfig.mk if Planet moves Android past security patch version 2019-07-05
  • Not compatible with SELinux enforcing
  • Only works when compiled as eng and not as userdebug

Compiling

The following patch is required to stop TWRP from trying to access a Keymaster2 device as Keymaster0 and segfaulting:

diff --git a/crypto/fde/cryptfs.cpp b/crypto/fde/cryptfs.cpp
index 8352296..cc0e039 100644
--- a/crypto/fde/cryptfs.cpp
+++ b/crypto/fde/cryptfs.cpp
@@ -424,6 +424,7 @@ static int keymaster_sign_object(struct crypt_mnt_ftr *ftr,
 #if TW_KEYMASTER_MAX_API >= 1
     keymaster0_device_t *keymaster0_dev = 0;
     keymaster1_device_t *keymaster1_dev = 0;
+    goto initfail;
     if (keymaster_init(&keymaster0_dev, &keymaster1_dev)) {
 #else
     keymaster_device_t *keymaster0_dev = 0;