[finitelife]

Long time listener, first time caller:

Since I couldn't find much specific info concerning the PaperWhite here (yes I know its a K5... kinda), I decided to share my current progress on building the kernel and modules. The end goal is to have OTG host mode, bluetooth, audio, and thumb drive support. That should keep me happy. Once I make some headway with this I will be posting an end to end walkthrough for the PW1. It will be from demo/brick/serial to jailbreak to kindlets to kual to root to optware to OTG to bt/sound/thumb. What I need from you people now is some guidance.

Notes:

• OS in use is Slackware64 14.1. If you use another OS (Ubuntu/Debian) it should still work fine.
• Build root is '~/' (home). To do this process from another directory, copy this post into an editor, the search and replace '~/' with whatever.
• Using a different toolchain should be as simple as replacing CROSS_COMPILE

Here we go:

1. Download and extract the Kindle source files
   

   #go to your home directory
   cd ~
   #download the Kindle source files (5.4.4.2)
   wget https://kindle.s3.amazonaws.com/Kind...3310003.tar.gz
   #extract the kindle sources
   tar xf ~/Kindle_src_5.4.4.2_2323310003.tar.gz

2. Select and Configure a Toolchain
   Use the packaged build_linaro-gcc:
   

   #make and move into our toolchain root
   mkdir ~/gplrelease/build; cd ~/gplrelease/build
   #extract toolchain sources to our location
   tar xf ~/gplrelease/build_linaro-gcc_4.5.4.tar.gz
   #make and package the toolchain
   make PREFIX=~/cross-linaro-gcc
   #go to your home directory
   cd ~
   #extract the configured toolchain to our location
   tar xf ~/gplrelease/build/cross-arm-linux-gnueabi-gcc-linaro-4.5-2011.05-0.tar.bz2
   #SUBSTITUTE THIS FOR CROSS_COMPILE IN SUBSEQUENT STEPS
   CROSS_COMPILE=~/cross-linaro-gcc/bin/arm-linux-gnueabi-

   ...or use a prebuilt toolchain
   Spoiler:

   
   

   #go to your home directory
   cd ~
   #download a simple arm toolchain
   wget https://sourcery.mentor.com/GNUToolc...ux-gnu.tar.bz2
   #extract your toolchain
   tar xf ~/arm-2014.05-29-arm-none-linux-gnueabi-i686-pc-linux-gnu.tar.bz2
   #SUBSTITUTE THIS FOR CROSS_COMPILE
   CROSS_COMPILE=~/arm-2014.05/bin/arm-none-linux-gnueabi-

3. Build uBoot's mkimage
   

   #make and move into our uBoot build root
   mkdir ~/gplrelease/uboot; cd ~/gplrelease/uboot
   #extract uBoot sources to our location
   tar xf ~/gplrelease/uboot_2009.08.tar.gz
   #set up our uBoot for our board
   make imx50_yoshi_config
   #make the tools (we only need mkimage)
   make CROSS_COMPILE=~/cross-linaro-gcc/bin/arm-linux-gnueabi- tools

4. Set up the Linux build
   

   #make and move into our Linux build root
   mkdir ~/gplrelease/linux; cd ~/gplrelease/linux
   #extract the linux sources to our location
   tar xf ~/gplrelease/linux-2.6.31.tar.gz
   #set up the kernel for our board (YOSHIME is PW1 WiFi, YOSHIME3 is PW1 3G)
   make ARCH=arm imx50_yoshime3_defconfig
   #configure the kernel options (I like menuconfig, but config, etc, also work)
   make ARCH=arm menuconfig

5. Kernel Configuration Notes (full .config attached 'yoshime3.config.tar')
   

   #Here are my working changes:
   CONFIG_KEXEC=y
   CONFIG_ATAGS_PROC=y
   
   CONFIG_NET_IPIP=m
   CONFIG_NET_IPGRE=m
   CONFIG_NET_IPGRE_BROADCAST=y
   CONFIG_IPV6=m
   
   CONFIG_IRDA=m
   CONFIG_USB_IRDA=m
   
   CONFIG_BT=m
   CONFIG_BT_L2CAP=m
   CONFIG_BT_RFCOMM=m
   CONFIG_BT_RFCOMM_TTY=y
   CONFIG_BT_HIDP=m
   CONFIG_BT_HCIBTUSB=m
   CONFIG_BT_HCIUART=m
   CONFIG_BT_HCIUART_H4=y
   
   CONFIG_TUN=m
   CONFIG_USB_USBNET=m
   
   CONFIG_SOUND=m
   CONFIG_SND=m
   CONFIG_SND_SEQUENCER=m
   CONFIG_SND_MIXER_OSS=m
   CONFIG_SND_PCM_OSS=m
   CONFIG_SND_DUMMY=m
   CONFIG_SND_USB_AUDIO=m
   
   CONFIG_HID_SUPPORT=y
   
   CONFIG_USB_DEBUG=y
   CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
   CONFIG_USB_GADGET_DEBUG_FILES=y
   CONFIG_USB_GADGET_DEBUG_FS=y
   CONFIG_USB_OTG=y
   CONFIG_USB_AUDIO=m
   CONFIG_USB_GADGETFS=m
   CONFIG_USB_G_SERIAL=m
   CONFIG_USB_MIDI_GADGET=m
   CONFIG_USB_GPIO_VBUS=m
   CONFIG_NOP_USB_XCEIV=m
   
   CONFIG_EXT4_FS=m
   CONFIG_EXT4DEV_COMPAT=y
   CONFIG_NTFS_FS=m
   CONFIG_NTFS_DEBUG=y
   CONFIG_NTFS_RW=y
   
   CONFIG_AUFS_FS=m
   

6. Fix the broken config includes
   

   #add Kexec support to the Kernel
   echo -e 'CONFIG_KEXEC=y\nCONFIG_ATAGS_PROC=y'>>~/gplrelease/linux/.config
   
   #add the yoshime[3] front light include (copy from uboot/include/linux/frontlight.h)
   cp ~/gplrelease/uboot/include/linux/frontlight.h ~/gplrelease/linux/include/linux/
   
   #fix yoshime[3] hall sensor include (copy yoshime_hall.h to lab126_hall.h and tweak it)
   sed 's/YOSHIME/LAB126/;s/struct yoshime_/#define HALL_MISC_DEV_NAME "hall"\n#define PATH_DEV_HALL "\/dev\/"HALL_MISC_DEV_NAME\nstruct /' ~/gplrelease/linux/include/linux/yoshime_hall.h >~/gplrelease/linux/include/linux/lab126_hall.h
   
   #fix yoshime3 mxc fb by disabling the useless NEON extensions
   chmod u+w ~/gplrelease/linux/include/linux/mxcfb.h
   cat << EOP >>~/gplrelease/linux/include/linux/mxcfb.h
   #define WAVEFORM_MODE_REAGL 0x8
   #define WAVEFORM_MODE_REAGLD 0x9
   #define TEMP_USE_AUTO 0x1001
   #define MXCFB_GET_WAVEFORM_TYPE _IOR('F', 0x39, __u32)
   #define WAVEFORM_TYPE_4BIT 0x1
   EOP
   chmod u-w ~/gplrelease/linux/include/linux/mxcfb.h
   sed -i 's/int mode_du4;/int mode_du4;int mode_reagl;int mode_reagld;/' ~/gplrelease/linux/include/linux/mxcfb.h
   sed -i 's/#ifdef __ARM_NEON__/#undef __ARM_NEON__\n#ifdef __ARM_NEON__/' ~/gplrelease/linux/drivers/video/mxc/mxc_epdc_fb.c

7. Compile the kernel and modules
   

   #make the uImage kernel
   make ARCH=arm CROSS_COMPILE=~/cross-linaro-gcc/bin/arm-linux-gnueabi- PATH=${PATH}:~/gplrelease/uboot/tools uImage
   #make the modules
   make ARCH=arm CROSS_COMPILE=~/cross-linaro-gcc/bin/arm-linux-gnueabi- tar-pkg

8. Update paths in modules.dep and finalize the tar
   

   #set the correct module path in modules.dep
   sed -i 's/kernel\//\/lib\/modules\/2.6.31-rt11-lab126\/kernel\//g' ~/gplrelease/linux/tar-install/lib/modules/2.6.31-rt11-lab126/modules.dep
   #merge the updated modules.dep into the final tar
   cd ~/gplrelease/linux/tar-install
   tar -uf ~/gplrelease/linux/linux-2.6.31-rt11-lab126.tar ./lib/modules/2.6.31-rt11-lab126/modules.dep
   cd ~/gplrelease/linux
   gzip ~/gplrelease/linux/linux-2.6.31-rt11-lab126.tar

9. BACK UP YOUR .config (full .config attached 'yoshime3.config.tar')
   

   #just copy your kernel config to outside the build root
   cp ~/gplrelease/linux/.config ~/gplrelease/yoshime3.config

10. You now have a file named ~/gplrelease/linux/linux-2.6.31-rt11-lab126.tar.gz containing the kernel and modules (mine is attached 'linux-2.6.31-rt11-lab126.tar.gz', don't blame me if you use it). I will edit to add how to load this onto your kernel shortly, but if you are doing this process you really should know how already.
11. ???
12. Brick or Profit

My questions now are:

• Does the PaperWhite 1 (i.MX508?) support OTG host mode?
• How do I sense/manually trigger OTG host mode?
• Is there a preferred way to load the kernel+modules on my Kindle so as to not brick it repeatedly?

Special thanks to MadMouse on HackThisSite IRC for the moral support, and shared coffees/cigarettes!

This post is updated and current to and including post #37