Revision as of 16:07, 21 December 2013

DISCLAIMER: Be careful with all your actions. The author of this page will not take any responsibility for you if you brick your device. YOU ARE DOING ALL THE FOLLOWING STEPS ON YOUR OWN. Please make sure your device is fully charged

Prerequisites:

• fastboot
  • Linux: 64-bit version in git of jollarecovery
  • Mac OS X: instructions
• mkbootimg (x64 Linux version in git of jollarecovery)
  • Linux: 64-bit version in git of jollarecovery
• Cross-compile toolchain for armv7hl-hardfloat-linux-gnueabi, if you want to compile your own kernel
• telnet client
• Patience
• MicroSD card with a minimum capacity of 16GB (formatted with a filesystem capable of storing files with 15GB size, e.g. ext4 or btrfs, not FAT32)

Using prebuilt image

• Download the boot image
• Start fastboot on your computer

 $ fastboot -i 0x2931 boot boot-telnet-initrd.img

• Power on Jolla while holding the volume down key pressed
• Jolla logo should appear, message "fastboot mode" on the very first line of the display
• Check if LED turns blue and wait for it to turn red after some time
• As soon as the LED is red, your network is up and running with the IP 192.168.42.17 and should be running a DHCP server
• Configure the USB networking on your computer accordingly
• Connect to Jolla using telnet

 $ telnet 192.168.42.17

• Mount your SD card

 $ mkdir /sd
 $ mount /dev/mmcblk1p1 /sd

• Backup all your internal eMMC partitons with:

 $ cd /dev
 $ for i in mmcblk0p* ; do echo $i; dd if=$i of=/sd/$i; done; sync

• Wait a long time until the command finishes
• Unmount the SD card

 $ umount /sd

• Reboot normally

Compile own kernel image

Create initrd tree

• Download source tree at: https://github.com/djselbeck/jollarecovery for example to /home/user/jollarecovery

Build Kernel image

• Download sources at: https://github.com/KonstaT/sailfishos_kernel_jolla_msm8930/
• export ARCH=arm
• export CROSS_COMPILE=armv7hl-hardfloat-linux-gnueabi- (replace with your arm crosscompiler)
• Make default config: make sbj_defconfig
• Change config with make menuconfig (see for e.x. https://github.com/djselbeck/jollarecovery/blob/master/kernelconfig)
• Set CONFIG_CMDLINE: root=/dev/ram0 rw init=/init androidboot.hardware=qcom user_debug=31 ehci-hcd.park=3 maxcpus=2
• Set CONFIG_CMDLINE_FORCE
• Set General Setup->Initramfs source file(s) to your path of initrd-root tree, example (/home/user/jollarecovery/root)
• make -j8 zImage
• create bootable image:
  • mkbootimg --cmdline --base 0x00000000 --pagesize 2048 --kernel_offset 0x80208000 --ramdisk_offset 0x82200000 --second_offset 0x81100000 --tags_offset 0x80200100 --board --ramdisk boot.img-ramdisk --kernel kernelsourcetreepath/arch/arm/boot/zImage --output "boot-telnet-initrd.img"