Android on Freerunner

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Android on Freerunner

Google has released their open source version of the Android phone software distribution. In order to use it on the Freerunner, a number of patches need to be applied and a compiler with armv4 java exception support needs to be used to compile the software.

Compiler suite

Android is a little picky about the version of gcc compiler. It also requires some java exception support that isn't available for armv4 without a minor modification. The following tools are what I use to build Android:


Binutils 2.18

At one time I had some armv5t code that was compiled into Android which would cause the linker to generate these blx instructions which fail on armv4. I'm not sure if this is still necessary, but I still have the following change applied to binutils:

diff -urN binutils-2.18-orig/bfd/elf32-arm.c binutils-2.18/bfd/elf32-arm.c
--- binutils-2.18-orig/bfd/elf32-arm.c	2007-08-07 02:59:23.000000000 +0700
+++ binutils-2.18/bfd/elf32-arm.c	2008-03-15 11:30:17.000000000 +0700
@@ -3093,8 +3093,8 @@
 static void check_use_blx(struct elf32_arm_link_hash_table *globals)
 {
   if (bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
-				Tag_CPU_arch) > 2)
-    globals->use_blx = 1;
+				Tag_CPU_arch) >= TAG_CPU_ARCH_V5T)
+    globals->use_blx = 0;
 }
 
 bfd_boolean


configure --prefix={devel path}/android/cross --target=arm-eabi

gcc 4.2.4 with gcc41-java-arm4.patch

configure --prefix={devel path}/android/cross --target=arm-eabi --with-arch=armv4t --enable-shared --enable-threads --disable-nls --disable-libmudflap --enable-target-optspace --with-abi=aapcs --enable-multilib --disable-libssp --disable-libstdcxx --enable-languages=c,c++

java-6-sun

This is the standard Linux package available for most (all?) distributions.

Patches

Coming soon. I've posted a number of them on the devel mailing list so far. Eventually, I expect to provide everything necessary for people to build Android for themselves.

Android on internal flash

Images

To use the Kernel you have to adjust your u-boot environment to support a Kernel of more then 2 MB or your have to change to the Qi Bootloader

I have placed an older 2.6.26 kernel with Android support at:

   uImage-android

I have put up a jffs2 image that replaces rootfs on the Freerunner at:

  androidfs.jffs2

Installation on internal flash

As noted above, this installation requires you to wipe out the existing kernel and rootfs in NAND on your Freerunner. You also must have an SDCARD and it needs to be configured with two (2) primary partitions: First is VFAT/MSDOS (16 or 32) which acts as the /sdcard storage area for pictures, movies, music, etc. and the Second is an ext3 primary partition for use of internal Android /data area to store settings, caches, etc.

The first thing I suggest is to setup an SDCARD. You can flash the NAND first, but you must have an SDCARD with two partitions as stated before you'll be able to boot. I use a 2GB card which I have split in half. fdisk shows me:

   /dev/mmcblk0p1               1        2454      996310    6  FAT16
/dev/mmcblk0p2 2455 4908 996324 83 Linux

formatted as

   sudo mkfs.vfat /dev/mmcblk0p1
sudo mkfs.ext3 /dev/mmcblk0p2

There is no need to populate the ext3 partition at all. The VFAT partition can be populated with media content if you so desire.

With your SDCARD all set, you are ready to flash the kernel and rootfs:

   sudo {path_to}/dfu-util -d 0x1d50:0x5119 -a kernel -D uImage-android
sudo {path_to}/dfu-util -d 0x1d50:0x5119 -a rootfs -D androidfs.jffs2


Android on SDcard

Some notes about booting android from sdcard :

Setup

  • Build android from source. See koolu website for directions.
  • Use the first script in this mail (adapt to your filesystem) to stage your android install.
  • copy the contents of this directory on a ext3 partition on your sdcard.
  • add a /boot directory on your sdcard.
  • copy andy's moredrivers kernel (for some reasons the uImage-android kernel does not boot on my GTA02 ?) from andy's page and copy it in your /boot with the exact name uImage-GTA02.bin
  • I changed the init.rc (in your root on the sd) to remove mounts that could be problematic (/data for example) in an attempt to make it work the dirty way.
  • Install Qi on you NAND flash. You can still boot whatever distro you've got on internal flash with the NOR bootloader. You should try the magic file in /boot to make it show debug info.
  • boot the GTA02, and pray.

Status

For the moment, the kernel boots, A N D R O I D appears (hurray), init.rc gets executed but nothing more happens after that.

Using adb to debug, it seems the root filesystem is still mounted read-only and then, the dalvik cache cannot initialize and android cannot start.

I had to remount the filesystem rw (using adb shell) and create the /data/dalvik-cache directory to go further.

Then I hit a problem with classes not found...Time to go to bed ;)

Phyce 23:38, 18 December 2008 (UTC)

Android Debug Bridge

To assist in debugging and to gain shell access to the phone with Android, you can

  adb

You should be able to connect to the phone as long as you start it up with the USB connected to your host. I don't think it will work if you plug it in after starting. Of course, you need to setup usb networking with ifconfig on your host before.

Some helpful commands are:

   ADBHOST=192.168.0.202 ./adb logcat           - like a tail -f of the android log
   ADBHOST=192.168.0.202 ./adb logcat -b radio  - same as above for the radio logs
   ADBHOST=192.168.0.202 ./adb shell            - bring up a command shell to the phone
   ADBHOST=192.168.0.202 ./adb kill-server      - kill the background server on the host

If you cannot to the device run "adb kill-server" before trying other commands.

Known Issues

This version of the linux kernel will not successfully wake from suspend mode. Your battery life will be significantly lowered because of this and the phone will lock up unless you setup the phones screen timeout to never.

This version of the kernel also uses a keypad hack. The buttons layout is as follows:

   Aux left-hand upper button is the "back" key.
   Power button is:
       menu button when pushed quickly,
       end button when held for more than a second and released,
       power-off if held for 10 seconds.

Distribution

Personal tools

Android on Freerunner

Google has released their open source version of the Android phone software distribution. In order to use it on the Freerunner, a number of patches need to be applied and a compiler with armv4 java exception support needs to be used to compile the software.

Compiler suite

Android is a little picky about the version of gcc compiler. It also requires some java exception support that isn't available for armv4 without a minor modification. The following tools are what I use to build Android:


Binutils 2.18

At one time I had some armv5t code that was compiled into Android which would cause the linker to generate these blx instructions which fail on armv4. I'm not sure if this is still necessary, but I still have the following change applied to binutils:

diff -urN binutils-2.18-orig/bfd/elf32-arm.c binutils-2.18/bfd/elf32-arm.c
--- binutils-2.18-orig/bfd/elf32-arm.c	2007-08-07 02:59:23.000000000 +0700
+++ binutils-2.18/bfd/elf32-arm.c	2008-03-15 11:30:17.000000000 +0700
@@ -3093,8 +3093,8 @@
 static void check_use_blx(struct elf32_arm_link_hash_table *globals)
 {
   if (bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
-				Tag_CPU_arch) > 2)
-    globals->use_blx = 1;
+				Tag_CPU_arch) >= TAG_CPU_ARCH_V5T)
+    globals->use_blx = 0;
 }
 
 bfd_boolean


configure --prefix={devel path}/android/cross --target=arm-eabi

gcc 4.2.4 with gcc41-java-arm4.patch

configure --prefix={devel path}/android/cross --target=arm-eabi --with-arch=armv4t --enable-shared --enable-threads --disable-nls --disable-libmudflap --enable-target-optspace --with-abi=aapcs --enable-multilib --disable-libssp --disable-libstdcxx --enable-languages=c,c++

java-6-sun

This is the standard Linux package available for most (all?) distributions.

Patches

Coming soon. I've posted a number of them on the devel mailing list so far. Eventually, I expect to provide everything necessary for people to build Android for themselves.

Android on internal flash

Images

To use the Kernel you have to adjust your u-boot environment to support a Kernel of more then 2 MB or your have to change to the Qi Bootloader

I have placed an older 2.6.26 kernel with Android support at:

   uImage-android

I have put up a jffs2 image that replaces rootfs on the Freerunner at:

  androidfs.jffs2

Installation on internal flash

As noted above, this installation requires you to wipe out the existing kernel and rootfs in NAND on your Freerunner. You also must have an SDCARD and it needs to be configured with two (2) primary partitions: First is VFAT/MSDOS (16 or 32) which acts as the /sdcard storage area for pictures, movies, music, etc. and the Second is an ext3 primary partition for use of internal Android /data area to store settings, caches, etc.

The first thing I suggest is to setup an SDCARD. You can flash the NAND first, but you must have an SDCARD with two partitions as stated before you'll be able to boot. I use a 2GB card which I have split in half. fdisk shows me:

   /dev/mmcblk0p1               1        2454      996310    6  FAT16
/dev/mmcblk0p2 2455 4908 996324 83 Linux

formatted as

   sudo mkfs.vfat /dev/mmcblk0p1
sudo mkfs.ext3 /dev/mmcblk0p2

There is no need to populate the ext3 partition at all. The VFAT partition can be populated with media content if you so desire.

With your SDCARD all set, you are ready to flash the kernel and rootfs:

   sudo {path_to}/dfu-util -d 0x1d50:0x5119 -a kernel -D uImage-android
sudo {path_to}/dfu-util -d 0x1d50:0x5119 -a rootfs -D androidfs.jffs2


Android on SDcard

Some notes about booting android from sdcard :

Setup

  • Build android from source. See koolu website for directions.
  • Use the first script in this mail (adapt to your filesystem) to stage your android install.
  • copy the contents of this directory on a ext3 partition on your sdcard.
  • add a /boot directory on your sdcard.
  • copy andy's moredrivers kernel (for some reasons the uImage-android kernel does not boot on my GTA02 ?) from andy's page and copy it in your /boot with the exact name uImage-GTA02.bin
  • I changed the init.rc (in your root on the sd) to remove mounts that could be problematic (/data for example) in an attempt to make it work the dirty way.
  • Install Qi on you NAND flash. You can still boot whatever distro you've got on internal flash with the NOR bootloader. You should try the magic file in /boot to make it show debug info.
  • boot the GTA02, and pray.

Status

For the moment, the kernel boots, A N D R O I D appears (hurray), init.rc gets executed but nothing more happens after that.

Using adb to debug, it seems the root filesystem is still mounted read-only and then, the dalvik cache cannot initialize and android cannot start.

I had to remount the filesystem rw (using adb shell) and create the /data/dalvik-cache directory to go further.

Then I hit a problem with classes not found...Time to go to bed ;)

Phyce 23:38, 18 December 2008 (UTC)

Android Debug Bridge

To assist in debugging and to gain shell access to the phone with Android, you can

  adb

You should be able to connect to the phone as long as you start it up with the USB connected to your host. I don't think it will work if you plug it in after starting. Of course, you need to setup usb networking with ifconfig on your host before.

Some helpful commands are:

   ADBHOST=192.168.0.202 ./adb logcat           - like a tail -f of the android log
   ADBHOST=192.168.0.202 ./adb logcat -b radio  - same as above for the radio logs
   ADBHOST=192.168.0.202 ./adb shell            - bring up a command shell to the phone
   ADBHOST=192.168.0.202 ./adb kill-server      - kill the background server on the host

If you cannot to the device run "adb kill-server" before trying other commands.

Known Issues

This version of the linux kernel will not successfully wake from suspend mode. Your battery life will be significantly lowered because of this and the phone will lock up unless you setup the phones screen timeout to never.

This version of the kernel also uses a keypad hack. The buttons layout is as follows:

   Aux left-hand upper button is the "back" key.
   Power button is:
       menu button when pushed quickly,
       end button when held for more than a second and released,
       power-off if held for 10 seconds.

Distribution