[Redmi K20 / Xiaomi Mi 9T Questions & Answers] nega_tive:
L:\K20 root\New folder (3)>fastboot flash boot boot.img

target reported max download size of 805306368 bytes

sending 'boot' (131072 KB)...

OKAY [ 2.835s]

writing 'boot'...

OKAY [ 0.657s]

finished. total time: 3.492s

L:\K20 root\New folder (3)>fastboot flash cache cache.img

target reported max download size of 805306368 bytes

erasing 'cache'...

OKAY [ 0.016s]

sending 'cache' (128 KB)...

OKAY [ 0.015s]

writing 'cache'...

OKAY [ -0.000s]

finished. total time: 0.031s

L:\K20 root\New folder (3)>fastboot flash cust cust.img

target reported max download size of 805306368 bytes

sending 'cust' (213156 KB)...

OKAY [ 4.618s]

writing 'cust'...

OKAY [ 0.000s]

finished. total time: 4.618s

L:\K20 root\New folder (3)>fastboot flash dtbo dtbo.img

target reported max download size of 805306368 bytes

sending 'dtbo' (32768 KB)...

OKAY [ 0.704s]

writing 'dtbo'...

OKAY [ 0.157s]

finished. total time: 0.861s

L:\K20 root\New folder (3)>fastboot flash dummy dummy.img

target reported max download size of 805306368 bytes

sending 'dummy' (8 KB)...

OKAY [ 0.000s]

writing 'dummy'...

FAILED (remote: (dummy) No such partition)

finished. total time: 0.000s

L:\K20 root\New folder (3)>fastboot flash dummy_devinf dummy_devinfo.img

target reported max download size of 805306368 bytes

sending 'dummy_devinf' (4 KB)...

OKAY [ 0.016s]

writing 'dummy_devinf'...

FAILED (remote: (dummy_devinf) No such partition)

finished. total time: 0.016s

L:\K20 root\New folder (3)>fastboot flash dummy_fsc dummy_fsc.img

target reported max download size of 805306368 bytes

sending 'dummy_fsc' (4 KB)...

OKAY [ 0.016s]

writing 'dummy_fsc'...

FAILED (remote: (dummy_fsc) No such partition)

finished. total time: 0.016s

L:\K20 root\New folder (3)>fastboot flash dummy_modemst dummy_modemst.img

target reported max download size of 805306368 bytes

sending 'dummy_modemst' (8192 KB)...

OKAY [ 0.188s]

writing 'dummy_modemst'...

FAILED (remote: (dummy_modemst) No such partition)

finished. total time: 0.188s

L:\K20 root\New folder (3)>fastboot flash logo logo.img

target reported max download size of 805306368 bytes

sending 'logo' (26980 KB)...

OKAY [ 0.588s]

writing 'logo'...

OKAY [ 0.144s]

finished. total time: 0.733s

L:\K20 root\New folder (3)>fastboot flash misc misc.img

target reported max download size of 805306368 bytes

sending 'misc' (4096 KB)...

OKAY [ 0.094s]

writing 'misc'...

OKAY [ 0.031s]

finished. total time: 0.125s

L:\K20 root\New folder (3)>fastboot flash persist persist.img

target reported max download size of 805306368 bytes

sending 'persist' (65536 KB)...

OKAY [ 1.406s]

writing 'persist'...

FAILED (remote: Partition is write protected)

finished. total time: 1.421s

L:\K20 root\New folder (3)>fastboot flash recovery recovery.img

target reported max download size of 805306368 bytes

sending 'recovery' (65536 KB)...

OKAY [ 1.421s]

writing 'recovery'...

OKAY [ 0.336s]

finished. total time: 1.757s

L:\K20 root\New folder (3)>fastboot flash system system.img

error: cannot load 'system.img'

L:\K20 root\New folder (3)>fastboot flash userdata userdata.img

target reported max download size of 805306368 bytes

sending 'userdata' (198244 KB)...

OKAY [ 4.278s]

writing 'userdata'...

OKAY [ 0.000s]

finished. total time: 4.278s

L:\K20 root\New folder (3)>fastboot flash vbmeta vbmeta.img

target reported max download size of 805306368 bytes

sending 'vbmeta' (4 KB)...

OKAY [ 0.016s]

writing 'vbmeta'...

OKAY [ 0.000s]

finished. total time: 0.016s

L:\K20 root\New folder (3)>fastboot flash vendor vendor.img

target reported max download size of 805306368 bytes

sending sparse 'vendor' (786428 KB)...

OKAY [ 18.024s]

writing 'vendor'...

OKAY [ -0.000s]

sending sparse 'vendor' (558016 KB)...

OKAY [ 13.004s]

writing 'vendor'...

OKAY [ -0.000s]

finished. total time: 31.043s