android-fastboot

# ALWAYS run these first
fastboot devices                    # Verify connection
fastboot getvar product             # Verify device model
fastboot getvar unlocked            # Must be "yes" for flashing
fastboot getvar current-slot        # Know current A/B slot
fastboot getvar battery-level       # Should be > 50

# 1. Enable OEM unlocking in Developer Options
# 2. Boot to fastboot
adb reboot bootloader
 
# 3. Unlock
fastboot flashing unlock
 
# 4. Confirm on device with volume keys + power
# WARNING: This wipes all data!

fastboot getvar unlocked            # yes/no
fastboot getvar device-state        # locked/unlocked
fastboot getvar unlock_ability      # Can be unlocked?

fastboot flash boot boot.img
fastboot flash recovery recovery.img      # Non-A/B only
fastboot flash dtbo dtbo.img
fastboot flash vbmeta vbmeta.img
 
# Disable verification (for custom ROMs)
fastboot flash --disable-verity --disable-verification vbmeta vbmeta.img

# These can hard-brick if wrong!
fastboot flash bootloader bootloader.img
fastboot reboot bootloader    # REQUIRED after bootloader flash
 
fastboot flash radio radio.img
fastboot reboot bootloader    # Recommended after radio flash

# Test before committing - reboots to normal after restart
fastboot boot recovery.img
fastboot boot patched_boot.img

# Check current slot
fastboot getvar current-slot        # Returns: a or b
 
# Set active slot
fastboot set_active a
fastboot set_active b
 
# Flash to specific slot
fastboot flash boot_a boot.img
fastboot flash boot_b boot.img
 
# Flash to both slots
fastboot --slot=all flash boot boot.img

# Enter userspace fastboot
fastboot reboot fastboot
 
# Check if in fastbootd
fastboot getvar is-userspace        # Should return: yes

# Must be in fastbootd mode!
fastboot reboot fastboot
 
fastboot flash system system.img
fastboot flash vendor vendor.img
fastboot flash product product.img

# Check snapshot status
fastboot getvar snapshot-update-status
 
# Cancel stuck update (CAREFUL!)
fastboot snapshot-update cancel

adb reboot recovery
# Or: Power + Volume Up (varies by device)

# 1. In recovery, select "Apply update from ADB"
# 2. Run:
adb sideload update.zip

# Test first (temporary boot)
fastboot boot twrp.img
 
# If it works, flash permanently
# Non-A/B devices:
fastboot flash recovery twrp.img
 
# A/B devices (recovery in boot):
fastboot flash boot twrp.img

# 1. Extract boot.img from your firmware
# 2. Transfer to device, patch with Magisk app
# 3. Pull patched image
adb pull /sdcard/Download/magisk_patched_*.img
 
# 4. Flash patched boot
fastboot flash boot magisk_patched_*.img
 
# 5. Reboot
fastboot reboot

adb shell su -c "magisk --version"
adb shell su -c "resetprop ro.debuggable 1"

fastboot erase userdata             # Wipe user data
fastboot erase cache                # Wipe cache (if exists)
fastboot -w                         # Format data + cache
 
# Full flash with wipe
fastboot -w flashall
fastboot -w update image.zip

# 1. Enter fastboot (Power + Vol Down)
fastboot devices
 
# 2. Flash stock boot
fastboot flash boot boot.img
 
# 3. For dynamic partitions
fastboot reboot fastboot
fastboot flash system system.img
fastboot flash vendor vendor.img
 
# 4. Wipe if needed
fastboot -w
 
# 5. Reboot
fastboot reboot