Session 08 — 2026-03-17
Phase: 03b (TWRP) · Key insight: everything we thought was a USB/init problem is actually an image format rejection.
Critical Findings
| Finding | Significance |
|---|---|
| fastboot error 0x50 — ABL rejects TWRP image | Kernel never starts — all USB/init debugging was premature |
| adb reboot recovery → fastboot menu | ABL interprets recovery reboot by entering visible fastboot menu (invisible on frozen EPDC) |
| fastboot data transfers broken in stock ABL | getvar/reboot work; flash/boot/download all stall |
| fastboot getvar: unlocked=yes, secure=no | Signature verification bypassed — image rejection is format issue, not signing |
| BCB loop entered | Device stuck: ABL reads boot-recovery → error 0x50 → fastboot menu → timeout → reboot |
| D+/GND cable → 05c6:900e (NOT 9008) | 900E = memory dump mode only, cannot write eMMC. Need proper 9008 cable. |
fastboot getvar all (key fields)
unlocked: yes | secure: no | product: sdm660 | kernel: uefi
max-download-size: 595230720 (~567 MB) | erase-block-size: 0x200Device stuck in BCB loop. Awaiting proper EDL 9008 cable to zero misc partition.