[Sony Xperia 5 III] go0:
I could really use some help here.

On a xperia 10 IV STEP #4 (BL unlock and root) works fine but STEP #5 trying to flash a GSI fails every time.

I've soft bricked my phone several times now every time I try to flash any GSI.

fastboot reboot fastboot says:

unknown reboot target fastboot

fastboot flash system_a LeOS-S-VNDKLITE-arm64-bvS.img says:

target reported max download size of 268435456 bytes

Invalid sparse file format at header magic

sending sparse 'system_a' 1/8 (254727 KB)...

OKAY [ 12.486s]

writing 'system_a' 1/8...

OKAY [ 1.998s]

sending sparse 'system_a' 2/8 (262128 KB)...

OKAY [ 14.353s]

writing 'system_a' 2/8...

OKAY [ 1.008s]

sending sparse 'system_a' 3/8 (262124 KB)...

OKAY [ 14.938s]

writing 'system_a' 3/8...

OKAY [ 1.013s]

sending sparse 'system_a' 4/8 (262116 KB)...

OKAY [ 14.976s]

writing 'system_a' 4/8...

FAILED (remote: Operation not permitted)

finished. total time: 61.702s

And then the phone is soft bricked...

I have not been able to get EMMA to work but luckily newflasher works.

EDIT:

So I found another version of fastboot which supports "fastboot reboot fastboot" but the same problem persists:

fastboot flash system_a system-squeak-arm64-ab-vndklite-floss-secure.img

target reported max download size of 268435456 bytes

Invalid sparse file format at header magic

sending sparse 'system_a' 1/10 (244948 KB)...

OKAY [ 13.911s]

writing 'system_a' 1/10...

OKAY [ 1.977s]

sending sparse 'system_a' 2/10 (259168 KB)...

OKAY [ 14.570s]

writing 'system_a' 2/10...

OKAY [ 0.958s]

sending sparse 'system_a' 3/10 (262140 KB)...

OKAY [ 14.872s]

writing 'system_a' 3/10...

OKAY [ 0.964s]

sending sparse 'system_a' 4/10 (262140 KB)...

OKAY [ 14.759s]

writing 'system_a' 4/10...

FAILED (remote: Operation not permitted)

finished. total time: 62.953s

Is there a different partition layout on the 10iv or something?

XQ-CC54:/ # cat /proc/partitions

major minor #blocks name

1 0 8192 ram0

1 1 8192 ram1

1 2 8192 ram2

1 3 8192 ram3

1 4 8192 ram4

1 5 8192 ram5

1 6 8192 ram6

1 7 8192 ram7

1 8 8192 ram8

1 9 8192 ram9

1 10 8192 ram10

1 11 8192 ram11

1 12 8192 ram12

1 13 8192 ram13

1 14 8192 ram14

1 15 8192 ram15

7 0 41324 loop0

7 8 876 loop1

7 16 7900 loop2

7 24 36216 loop3

7 32 111952 loop4

7 40 1724 loop5

7 48 7900 loop6

7 56 2140 loop7

7 64 111952 loop8

7 72 876 loop9

7 80 41324 loop10

7 88 36216 loop11

7 96 268 loop12

7 104 8032 loop13

7 112 11272 loop14

7 120 748 loop15

254 0 3145728 zram0

8 0 124936192 sda

8 1 8192 sda1

8 2 32768 sda2

8 3 16384 sda3

8 4 64 sda4

8 5 64 sda5

8 6 512 sda6

8 7 3072 sda7

8 8 4096 sda8

8 9 4096 sda9

8 10 512 sda10

8 11 512 sda11

8 12 1536 sda12

8 13 1536 sda13

8 14 512 sda14

8 15 512 sda15

259 0 174080 sda16

259 1 174080 sda17

259 2 128 sda18

259 3 128 sda19

259 4 256 sda20

259 5 256 sda21

259 6 2048 sda22

259 7 2048 sda23

259 8 128 sda24

259 9 3072 sda25

259 10 3072 sda26

259 11 64 sda27

259 12 64 sda28

259 13 2048 sda29

259 14 2048 sda30

259 15 98304 sda31

259 16 98304 sda32

259 17 1024 sda33

259 18 1024 sda34

259 19 399360 sda35

259 20 399360 sda36

259 21 32768 sda37

259 22 32768 sda38

259 23 4 sda39

259 24 256 sda40

259 25 8192 sda41

259 26 128 sda42

259 27 1024 sda43

259 28 8 sda44

259 29 1024 sda45

259 30 512 sda46

259 31 16384 sda47

259 32 32768 sda48

259 33 16384 sda49

259 34 28 sda50

259 35 512 sda51

259 36 16384 sda52

259 37 32 sda53

259 38 32 sda54

259 39 64 sda55

259 40 64 sda56

259 41 64 sda57

259 42 64 sda58

259 43 24576 sda59

259 44 24576 sda60

259 45 65536 sda61

259 46 65536 sda62

259 47 1024 sda63

259 48 512 sda64

259 49 2048 sda65

259 50 128 sda66

259 51 512 sda67

259 52 512 sda68

259 53 98304 sda69

259 54 98304 sda70

259 55 819200 sda71

259 56 819200 sda72

259 57 12058624 sda73

259 58 109242348 sda74

259 59 20480 sda75

8 16 8192 sdb

8 17 7956 sdb1

8 18 192 sdb2

8 32 8192 sdc

8 33 7956 sdc1

8 34 192 sdc2

179 0 7565312 mmcblk1

179 1 7564288 mmcblk1p1

253 0 1024436 dm-0

253 1 269616 dm-1

253 2 900396 dm-2

253 3 1675816 dm-3

253 4 1094280 dm-4

253 5 1576 dm-5

253 6 1008188 dm-6

253 7 886108 dm-7

253 8 1649292 dm-8

253 9 1076928 dm-9

253 10 1468 dm-10

7 128 7032 loop16

7 136 19104 loop17

7 144 2804 loop18

7 152 5020 loop19

7 160 268 loop20

7 168 64052 loop21

7 176 6204 loop22

7 184 12652 loop23

7 192 4440 loop24

7 200 1908 loop25

7 208 6564 loop26

7 216 5796 loop27

7 224 736 loop28

7 232 3884 loop29

253 11 109242348 dm-11

253 12 7956 dm-12

253 13 11172 dm-13

253 14 728 dm-14

253 15 6964 dm-15

253 16 18944 dm-16

253 17 2768 dm-17

253 18 4968 dm-18

253 19 256 dm-19

253 20 63540 dm-20

253 21 6144 dm-21

253 22 12540 dm-22

253 23 4392 dm-23

253 24 1880 dm-24

253 25 6500 dm-25

253 26 5736 dm-26

253 27 716 dm-27

253 28 3840 dm-28