FENG Yu Ning wrote:
SST49LF080A has a #TBL pin deciding whether writes to the top boot block is protected.
Correct. It is most likely the cause. But - it would also be interesting if you could measure the voltage Samuel, on pin 8 after having run flashrom in any mode.
- if someone has access to the BCM5875(HT1000) datasheet, (s)he may check whether there are registers that control the output to the #TBL pin, then improves flashrom.
Unfortunately (or fortunately, because that Broadcom data book is probably difficult to find) TBL# (and often WP# too) is usually connected to a GPIO on some chip. (And that chip may be easier to find docs for.) But - this Broadcom chipset could have dedicated pin, I'm not ruling it out.
//Peter