Developer FAQ & Common errors

This information is outdated because of the REWRITE.

---

First of all

If you cannot boot into efidroid or you try to do boot another ROM from within efidroid and it fails: reboot to efidroid again! It will show you an error message which help you to identify the issue.

Table of Contents

• 1. efidroid boots but it unusable because of graphic issues
• 2. 64bit only: TWRP boot fails (ptrace error)
• 3. Graphical glitches e.g. at the bottom of the screen (especially on hi-res screens)
• 4. no suitable device tree found error pops up while booting

---

1. efidroid boots but it unusable because of graphic issues

• Cause: If you use DMA in your lk_inc.mk ( WITH_2NDSTAGE_DISPLAY_DMA_TRIGGER ) you may need to adjust the trigger delay
• Solution: Increase the value in target_display.c

---

2. 64bit only: TWRP boot fails (ptrace error)

when i select TWRP to flash a new ROM it does not boot into TWRP.. failure is: ptrace(PTRACE_SETREGSET,477,0x404,0x7fc5d88fa0) invalid argument ... (or similar)

• Cause: You need to have a patched TWRP kernel
• Solution: modify your kernel sources https://github.com/M1cha/android_kernel_xiaomi_libra/commit/2e174acab07f25dc52d052c68e61e0b256833005 https://github.com/M1cha/android_kernel_xiaomi_libra/commit/ca992e36c7b38d22535350381fed0ad841c97a0c
• in case your kernel is very old, here's the full log for that file so you can compare: https://github.com/M1cha/android_kernel_xiaomi_libra/commits/cm-14.1/arch/arm64/kernel/ptrace.c

---

3. Graphical glitches e.g. at the bottom of the screen (especially on hi-res screens)

• Cause: EFIDroid allocates 8MB by default for the screen buffer. Your device's screen resolution is too high to fit inside 8MB.
• Solution: increase LCD_VRAM_SIZE in your config.ini: e.g. LCD_VRAM_SIZE = 0x1000000

---

4. no suitable device tree found error pops up while booting

• Solution : Add DEVICE_PREFER_ATAGS_HWID := 1 in your lk_inc.mk