#!/bin/bash
# B7C rollback — restore the T4 cache (9d3bc890, operational since 2026-10-02: B6P + telnetd). Needs 9008 via HW EDL (D+->GND). boot/aboot untouched.
# Deeper rollback: r2/t4/T4-rollback.sh (B6P 9fea693a), b6p/B6P-rollback.sh (B5b golden mm1, 409bbb11).
cd ~/doc/modem/jz08-aurora || exit 1
L=firehose/007050e100000000_394a2e47cf830150_fhprg_peek.bin ; O=logs/b7/b7c/rollback ; mkdir -p $O
B=r2/t4/cache-extlinux-t4.img
[ "$(sha256sum $B | cut -d' ' -f1)" = 9d3bc8900ab4b4ec26cfb16d2a0e83a8b3f8f4b74793e842bccfd366263368b7 ] || { echo "STOP: rollback image hash"; exit 1; }
lsusb | grep -q 05c6:9008 || { echo "STOP: no 9008"; exit 1; }
edl --loader=$L printgpt > $O/00-printgpt.log 2>&1
edl --loader=$L w cache $B > $O/cache-w.log 2>&1
edl --loader=$L r cache $O/cache-rb.bin > /dev/null 2>&1 ; cmp $B $O/cache-rb.bin && echo CACHE_RESTORED_T4
sha256sum $B $O/cache-rb.bin