リセットとフリーズで解析する電子辞書リバエン記 / reverse-engineer-e-dictionaries-with-reset-and-freeze

by Takumi Sueda

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Kernel/VM online part 4 LT @puhitaku

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Takumi Sueda @puhitaku NICT   HOMMA Inc.   Twitter  

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SHARP Brain SHARP Windows CE   CE exe (PE) 2011 TOSHIBA TMPA 9 10 CRAXBG (armv 5 tej) + 64 MiB DRAM Windows CE 2012 2020 NXP i.MX 2 83 (armv 5 tej) + 12 8 MiB DRAM Windows CE 2021 ??? SHARP Brain 3 https://jp.sharp/edictionary/products/pwsh 1 _overviiew.html

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SHARP Brain 2019 2020 SHARP Brain PW-SH 1 Linux + i.MX 283 Raspberry Pi Brain Linux SD Brain Linux 4 https://jp.sharp/edictionary/products/pwsh 1 _overviiew.html

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2021 1 Brain

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Brain https://jp.sharp/edictionary/topics/ 6

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Brain https://brain-library.com/ 7

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Brain OS   SoC i.MX 283 8

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Brain 9

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Brain 10

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Brain 11

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Brain SoC NXP i.MX 7 ULP i.MX 7 ULP = Cortex-A 7 + Cortex-M 4 12

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Brain (Windows CE PE) OS 13

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No content

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  objdump 0 Arm 15

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  as ELF .text 16

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resource hog 18  

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_start return 19

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0x 00 0000 00   21

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return 0 x 0 00000 0 0 22

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U-Boot

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U-Boot 1 . MMU 2 . MMU U-Boot U-Boot 24

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U-Boot & OS API JTAG UART TX UART   I/O 25

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U-Boot     1bit 26

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U-Boot 1 MMU

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U-Boot MMU MMU mrc SCTSR MMU mcr MMU 28 SCTSR

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U-Boot MMU mrc   29

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U-Boot MMU 30

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U-Boot MMU mrc SCTSR return 31

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U-Boot 2 U-Boot

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U-Boot U-Boot U-Boot MMU   U-Boot 3 : 1 . Brain 2 . DRAM 1. 1. 3 . 2. 64 KiB (large page) 1. U-Boot 33

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U-Boot 2 U-Boot 1

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U-Boot U-Boot 1 35 Brain 1 MiB NOP mov pc, lr NOP = mov r0, r0

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U-Boot U-Boot 1 36 1 5 MiB Brain 15 MiB 1 ( 4 Bytes) 1 5 MiB DRAM 128 MiB 11.7%

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U-Boot 2 U-Boot 2  

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U-Boot U-Boot 38 NOP MMU NOP 1 NOP 6 4 KiB NOP NOP ……… 2 1

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U-Boot U-Boot 2 39 Virtual   Memory 1 5 MiB 1 MMU Physical   Memory MMU

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U-Boot U-Boot 2 40 1 Physical   Memory 0 x 6000 000 0 0 x 6800 000 0 1   !"#$ %&'( !"#$ 1

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U-Boot U-Boot 2 41 1 Physical   Memory 0 x 6 78000 0 0 DRAM 15 MiB   %&'( 0 x 6000 000 0 0 x 6800 000 0

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U-Boot 2 U-Boot 3  

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U-Boot U-Boot 43 2   MMU NOP NOP 6 4 KiB NOP 3 1 NOP NOP NOP NOP

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U-Boot U-Boot 44 112 64 KiB NOP NOP 6 4 KiB 3 1 NOP NOP NOP NOP 112 …

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U-Boot U-Boot 1 . ✅ U-Boot 2 . ✅ MMU 3 . ✅ MMU U-Boot 1 5 MiB 0x 7 0 0 0 0 0 u-boot.bin   0x 67 800000 U-Boot U-Boot 45