4 ms·
> This can be bad if a particular memory cell has failed. If every variable has a fixed address, and one of those addresses goes bad, a patch can be loaded to m
by coppsilgold 10mo ago
> This can be bad if a particular memory cell has failed. If every variable has a fixed address, and one of those addresses goes bad, a patch can be loaded to move that address and the mission can continue.
This seems like a rather manual way to go about things for which an automated solution can be devised. Such as create special ECC memory where you also account for entire cell failure with Reed-Solomon coding or some boot process which blacklists bad cells etc.
- j16sdiz 10mo agoIt is more than that. This is what make remote debugging possible. It is impossible to do interactive remote debugging over a ultra low bandwidth link. If everything have static address and deterministic static, you can have a exact copy on ground and debug there.
- varjag 10mo agoInteractive debugging is apparently possible and was reportedly done on Deep Space One mission. One of developers involved frequents HN I believe.
- unloader6118 10mo agoKind of. That took hours of not days. A local exact replica with deterministic state save lots of time.
- coppsilgold 10mo ago> If everything have static address and deterministic static, you can have a exact copy on ground and debug there. You can also have deterministic dynamic - the satellite could transmit its dynamic state (a few bits signifying which memory cells failed) and then you proceed deterministically on the ground.