GTI9100GBootloaderFreedom » History » Version 17
Denis 'GNUtoo' Carikli, 03/17/2020 04:43 PM
1 | 1 | Denis 'GNUtoo' Carikli | h1. I9100GBootloader |
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3 | 9 | Denis 'GNUtoo' Carikli | {{toc}} |
4 | 3 | Denis 'GNUtoo' Carikli | |
5 | 11 | Denis 'GNUtoo' Carikli | h2. How to check if you have a signed bootloader |
6 | 3 | Denis 'GNUtoo' Carikli | |
7 | 11 | Denis 'GNUtoo' Carikli | h3. How to check from the bootloader interface to install the recovery. |
8 | 7 | Denis 'GNUtoo' Carikli | |
9 | 8 | Denis 'GNUtoo' Carikli | To do that you need to get into the ODIN MODE that is typically used to install the Replicant recovery: |
10 | 1 | Denis 'GNUtoo' Carikli | |
11 | 7 | Denis 'GNUtoo' Carikli | # Start the device by holding the following key combination: *Volume down, Select, Power*, |
12 | # Hold the key combination until the device shows a *Warning* message. |
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13 | # Confirm that you want to download a custom OS using volume up |
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14 | # Make sure the device is in *Downloading* mode |
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15 | |||
16 | When this is done, it should show some text: |
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17 | <pre> |
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18 | ODIN MODE |
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19 | PRODUCT NAME: GT-I9100G_CHN_CHN |
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20 | </pre> |
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22 | 10 | Denis 'GNUtoo' Carikli | Here CHN_CHN probably refers to the Chinese version. And it looks like that version has a signed bootloader: According to "a thread on the XDA developers forum":https://forum.xda-developers.com/galaxy-s2/development/guide-repair-totally-sleep-dead-boot-t1701471 "Means that you own a chinese bootloader locked I9100G. You can't flash any other bootloader than the chinese one." |
23 | 1 | Denis 'GNUtoo' Carikli | |
24 | 12 | Denis 'GNUtoo' Carikli | h3. How to check with command line utilities |
25 | 5 | Denis 'GNUtoo' Carikli | |
26 | 1 | Denis 'GNUtoo' Carikli | To get the bootrom to try to boot on USB, you need to do the following: |
27 | * Connect the USB cable to the device but make sure it's not connected on the computer. |
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28 | * Power off the device |
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29 | * Connect the USB cable |
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30 | |||
31 | If we do that, we get the following in the kernel log of your laptop: |
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32 | <pre> |
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33 | usb 1-1: new high-speed USB device number 24 using ehci-pci |
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34 | usb 1-1: unable to get BOS descriptor or descriptor too short |
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35 | usb 1-1: New USB device found, idVendor=0451, idProduct=d00f, bcdDevice= 0.00 |
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36 | usb 1-1: New USB device strings: Mfr=33, Product=37, SerialNumber=0 |
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37 | usb 1-1: Product: OMAP4430 |
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38 | usb 1-1: Manufacturer: Texas Instruments |
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39 | </pre> |
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40 | |||
41 | We can also try to get a bit more infos with omap-usb-boot: |
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42 | <pre> |
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43 | $ sudo omap-usb-boot -v -w boot invalidbootmedia |
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44 | Finding and opening USB device |
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45 | Found and opened omap4 USB device: OMAP4430 |
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46 | ASIC device id: 4430, HS device |
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47 | Booting from device invalidbootmedia... |
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48 | Booting device invalidbootmedia not found |
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49 | Booting from device failed |
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50 | </pre> |
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51 | |||
52 | Here we know the device is signed because it's a "HS device". |
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53 | If it was not signed it would print "GP device" instead. |
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54 | 9 | Denis 'GNUtoo' Carikli | |
55 | 11 | Denis 'GNUtoo' Carikli | h3. Using the Android version or other devices properties? |
56 | 9 | Denis 'GNUtoo' Carikli | |
57 | 15 | Denis 'GNUtoo' Carikli | "hpagseddy/i9100g_xloader":https://github.com/hpagseddy/i9100g_xloader is based on "ths-backup/i9100g_xloader":https://github.com/ths-backup/i9100g_xloader which has an ics (Icecream Sandwitch, an Android version) branch only. According to hpagseddy, that branch is also used for Android Jelly brean. |
58 | 9 | Denis 'GNUtoo' Carikli | |
59 | It's still unclear if there is some correlation between Android version and signed bootloaders. |
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60 | |||
61 | The device that was given to [[People#Denis-GNUtoo-Carikli|GNUtoo]] that has a signed bootloader also has the following characteristics: |
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62 | |||
63 | *Software state*: Running the stock OS, unmodified |
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64 | *Android version*: Android 2.3.6 |
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65 | *Baseband version*: IG9100GZCLC2 |
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66 | *Build number*: GINGERBREAD.ZCLC2 |
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67 | *Kernel version*: 2.6.35.7 se.infra@SEI-30#2 |
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69 | 17 | Denis 'GNUtoo' Carikli | |
70 | According to "a thread on XDA":https://forum.xda-developers.com/galaxy-s2/development/bootloader-t1754158 there is a corelation between the @Baseband version@ and the geographic zone that is targeted. While the list of baseband versions is incomplete, we can still use it to avoid the Chinese version (CHN_CHN) which has a signed bootloader. |
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71 | |||
72 | At this point it's also still unclear if any of the other characteristics above correlate to signed or unsigned bootloaders. |
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73 | 2 | Denis 'GNUtoo' Carikli | |
74 | h2. Source code |
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75 | |||
76 | * https://github.com/hpagseddy/i9100g_xloader This got rebuilt and flashed, and it worked on the device it was tested on. |
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77 | * https://blog.the-leviathan.ch/?p=408 |
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79 | 1 | Denis 'GNUtoo' Carikli | h2. TODO |
80 | |||
81 | 16 | Denis 'GNUtoo' Carikli | * Document the various firmware version mentioned here: https://www.sammobile.com/samsung/galaxy-s2/firmware/#GT-I9100G |
82 | 1 | Denis 'GNUtoo' Carikli | * Understand how to get unsigned versions (Android version, serial number, etc) |
83 | 13 | Denis 'GNUtoo' Carikli | * Get a device with an unsigned bootloader and u-boot and ask samsung for source code |
84 | 14 | Denis 'GNUtoo' Carikli | * Check the boot order on unsigned devices (is it possible to boot from USB easily?) |
85 | 6 | Denis 'GNUtoo' Carikli | * Try to boot the xloader nevertheless, as the device could be in some "verify but not enforce mode" for signatures |