Jibo Revival Docs

02 - Mapping to guide

3 min read

Mapping to guide.md

This page explains how the automated installer in ../jibo_automod.py relates to the manual steps in ../guide.md.

Big picture

../guide.md is the “do it by hand” method.

../jibo_automod.py is the “do the same steps, but scripted” method.

If something goes wrong in automation, the guide is still valuable because it explains:

  • how to confirm RCM mode
  • how to interpret partition layouts
  • what /var/jibo/mode.json does conceptually

Step-by-step mapping

Part 1 (Connecting / RCM)

Guide:

  • Enter RCM mode and confirm with lsusb showing NVIDIA APX (0955:7740).

Tool:

  • detect_jibo_rcm() tries lsusb on Linux.
  • Falls back to scanning /sys/bus/usb/devices if lsusb is missing.
  • On Windows it can’t reliably detect in the same way, so it prints guidance and proceeds.

Related: 05 - Windows Support

Part 2 (Build ShofEL)

Guide:

  • Clone/build ShofEL manually with make.

Tool:

  • build_shofel() runs make inside ../Shofel/.
  • If payload .bin files are missing, it requires the ARM toolchain (arm-none-eabi-gcc).

Part 3 (Dump eMMC)

Guide:

  • Run: shofel2_t124 EMMC_READ 0x0 0x1D60000 full_jibo_dump.bin

Tool:

  • Default full workflow calls dump_emmc() which runs the same command.
  • Fast workflow (--mode-json-only) does not dump full eMMC; it only reads GPT + /var.

Part 4 (Identify and extract /var)

Guide:

  • Run fdisk -l dump.bin
  • Find partition 5, compute start/count, then dd out var_partition.bin.

Tool:

  • Parses GPT directly (parse_gpt_partitions()), with an fdisk fallback on Linux.
  • Then extracts bytes by seeking directly inside the dump (no dd needed).
  • Uses heuristics to identify /var (partition #5 and roughly 400–600MB).

Part 4.2 (Edit mode.json)

Guide:

  • Mount loop device and edit jibo/mode.json.

Tool:

  • On Linux: prefers a loop mount and edits mode.json.
  • On Windows: prefers debugfs if installed.
  • Raw in-place patch is last resort.

Related: 01 - Installer (How It Works)

Part 5 (Write /var back)

Guide:

  • Convert start sector to hex and run EMMC_WRITE <start> var_partition.bin.

Tool:

  • Always uses the GPT-derived start sector (so you don’t manually convert it).
  • In fast mode, it can patch-write only changed sectors instead of writing the full 500MB.

Part 6 (Verify)

Guide:

  • Read back and compare hashes.

Tool:

  • Optional verify step reads back the written range and compares MD5.

Why the automated tool differs from the guide

The guide is intentionally explicit and teaches the mental model.

The tool tries to reduce “math + manual disk ops” by:

  • parsing GPT automatically
  • extracting partitions programmatically
  • handling mount/debugfs edits
  • optionally patch-writing only changed sectors

When to fall back to the guide

  • If your partition layout differs enough that /var isn’t partition 5.
  • If the filesystem inside /var is corrupted and mount/debugfs can’t read it.
  • If you want a full backup regardless of speed (the guide defaults to full dump).

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