support "sideload over ADB" mode
Rather than depending on the existence of some place to store a file
that is accessible to users on an an unbootable device (eg, a physical
sdcard, external USB drive, etc.), add support for sideloading
packages sent to the device with adb.
This change adds a "minimal adbd" which supports nothing but receiving
a package over adb (with the "adb sideload" command) and storing it to
a fixed filename in the /tmp ramdisk, from where it can be verified
and sideloaded in the usual way. This should be leave available even
on locked user-build devices.
The user can select "apply package from ADB" from the recovery menu,
which starts minimal-adb mode (shutting down any real adbd that may be
running). Once minimal-adb has received a package it exits
(restarting real adbd if appropriate) and then verification and
installation of the received package proceeds.
Change-Id: I6fe13161ca064a98d06fa32104e1f432826582f5
diff --git a/minadbd/README.txt b/minadbd/README.txt
new file mode 100644
index 0000000..0c190d0
--- /dev/null
+++ b/minadbd/README.txt
@@ -0,0 +1,27 @@
+The contents of this directory are copied from system/core/adb, with
+the following changes:
+
+adb.c
+ - much support for host mode and non-linux OS's stripped out; this
+ version only runs as adbd on the device.
+ - does not setuid/setgid itself (always stays root)
+ - only uses USB transport
+ - references to JDWP removed
+ - main() removed
+
+adb.h
+ - minor changes to match adb.c changes
+
+sockets.c
+ - references to JDWP removed
+
+services.c
+ - all services except echo_service (which is commented out) removed
+ - all host mode support removed
+ - sideload_service() added; this is the only service supported. It
+ receives a single blob of data, writes it to a fixed filename, and
+ makes the process exit.
+
+Android.mk
+ - only builds in adbd mode; builds as static library instead of a
+ standalone executable.