Differences

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--- doc:appunti:hardware:xiaomi_mi_a1 [2020/03/25 15:47] – [March 2020 security update] niccolo
+++ doc:appunti:hardware:xiaomi_mi_a1 [2020/09/23 17:06] (current) – [August 2020 security update] niccolo
@@ Line 10: / Line 10: @@
 ^ Internal Memory  | 32 Gb   |
 ^ CPU              | Qualcomm Snapdragon 625 2.0GHz 8-core  |
+^ Architecture     | arm64-v8a  |
 ^ Screen           | 5.5 Inches, 1920 x 1080  |
 ^ Connector        | USB Type C  |
@@ Line 347: / Line 348: @@
 </code>
-**I got a problem** during this step: may be the **boot_b.img** was not the current one, but one of two versions before! Luckily the only negative effect was that **the WiFi was not working**. This is a **logcat** excerpt:
+I got **a problem** during this step: may be the **boot_b.img** was saved from version **9.6.8.0**, not from the currently installed **10.0.14.0**. Luckily enough, the only negative effect was that **the WiFi was not working**. This is a **logcat** excerpt:
 <code>
@@ Line 356: / Line 357: @@
 </code>
-I proceeded with the standard procedure, trusting that the boot partition would be recognized as original and therefore upgradeable (remember: the update were already downloaded by the phone, so I just launched the reboot and install procedure). After some minutes and three reboots, the system was upgraded; **Android v.9** and build number **PKQ1.180917.001.V10.0.19.0.PDHMIXM**. Fortunately enough the WiFi were recovered.
+I proceeded with the standard upgrade path, trusting that the boot partition would be recognized as original and therefore upgraded to the new one. Remember: the update ZIP archive were already downloaded into the phone, so I just launched the **reboot and install** action. After some minutes and a few reboots, the system was upgraded to **Android v.9** build number **PKQ1.180917.001.V10.0.19.0.PDHMIXM**. Fortunately enough the WiFi were recovered.
+To complete the upgrade:
+  - Copy **twrp-installer-3.3.0-2-tissot.zip** and **Magisk-v20.1.zip** into the phone internal storage.
+  - Backup the stock boot partitions.
+  - Reinstall TWRP.
+  - Reinstall Magisk.
+  - Backup the rooted boot partitions.
+First of all **run the TWRP** recovery //fastbooting// the image directly from the PC hard disk (i.e. **without installing it into the phone**):
+<code>
+adb reboot bootloader
+fastboot boot twrp-3.3.0-2-tissot.img
+</code>
+From //TWRP// => //Reboot// menu, I verified that the **Current Slot** is **A**: it is normal that the upgrade procedure swaps the boot partition during the upgrade. Using ADB from the connected PC, I backed up the stock boot images:
+<code>
+adb pull /dev/block/mmcblk0p22 boot_a.img
+adb pull /dev/block/mmcblk0p23 boot_b.img
+</code>
+Now I installed the TWRP recovery into the boot partitions: from //TWRP// => //Install// => **twrp-installer-3.3.0-2-tissot.zip**. The installation warns about //Running boot image patcher on slot// A and B, and spit some harmless warnings about the **/vendor** mounting point. It is necessary to install TWRP before Magisk, otherwise TWRP will unroot the phone during its install.
+After a system reboot, and another boot into Recovery, I did //TWRP// => //Install// => **Magisk-v20.1.zip**. This will install //root// on the phone(the **su** program). Once again I got some harmless warnings about the /vendor mounting point.
+Finally I repeated the procedure to **backup** the patched **boot_a** and **boot_b** partitions.
+**NOTICE**: the ADB client required to perform the ''adb pull'' command is active when I boot TWRP using ''fastboot boot twrp-3.3.0-2-tissot.img''. If instead I boot TWRP from the phone, the ADB client is not active.
+Once rebooted the phone into normal system, I installed the root permissions manager: **MagiskManager-v7.5.1.apk**.
+===== August 2020 security update =====
+This is a new update from Xiaomi, still featuring **AndroidOne v.9** relase, build **PKQ1.180917.001.V10.0.24.0.PDHMIXM**. The upgrade was downloaded nightly over the WiFi. It seems impossibile to prevent such automatic download: I did not find any settings to prevent automatic upgrade download. After downloading, the phone asks to reboot to complete the upgrade.
+The starting conditions were:
+  * A/B System Updates status: **Current Slot: ?** (may be it was **A**, because after installation it is **B**).
+  * Bootloader is **unlocked**.
+  * **Magisk** and **TWRP** were installed, but may be they were hidden by accident. Infact the installation of the upgrade went OK after a reboot, whereas it should fail because the boot sector is tampered with **Magisk su**.
+  * **System partition** was the stock one: root privileges were never used to tamper the **/system** hierarchy.
+After the upgrade, I did the following to get **root again**:
+  * adb reboot bootloader
+  * fastboot boot twrp-3.3.0-2-tissot.img
+  * Verified from TWRP => Reboot: **Current slot: B**
+  * adb pull /dev/block/mmcblk0p22 boot_a.img
+  * adb pull /dev/block/mmcblk0p23 boot_b.img
+  * TWRP ⇒ Install ⇒ **twrp-installer-3.3.0-2-tissot.zip**\\ Running boot image patcher on slot a and b.
+  * system reboot
+  * adb reboot bootloader
+  * fastboot boot twrp-3.3.0-2-tissot.img
+  * TWRP ⇒ Install ⇒ **Magisk-v20.4.zip**\\ Current boot slot: _b, unpacking, patching, repacking, flashing new boot image.
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