Hello all SerialICE folks !
You may have noticed the new filter system Simba has been merged for SerialICE. Written in LUA, as its predecessor, the new scripting system has greatly improved in terms of the log readability.
I am sort of hoping someone of the few people recently playing around with the updated SerialICE would give a helping hand here and coordinate what to do with the existing documentation at serialice.org. Also don't destroy your existing logs, I could probably use some more nice sample runs.
This is a very very brief introduction, I hope this answers some of the questions that have come up on #coreboot. Maybe SerialICE wiki is the way to go?
1. Target system setup
People have contributed some new boards but essentially nothing has changed here. There is a menuconfig option to set the size of the Flash chip you are going to use, this information wasn't on the website "Getting Started" section.
You should try with picocom/minicom that your target responses with a single SerialICE prompt. If you get many, there might be some watchdog that repeatedly triggers reset on the target.
2. Host system setup
You need to build Qemu from the SerialICE git tree. Take note that LUA library version >= 5.2 must be installed.
To run Qemu session on a 32bit host, you will need to build LUA from source with the patches under serialice/SerialICE/patches applied. The patch is to extend LUA's (signed) integer to 64bits, since we need to handle addresses close to 2^32.
Fetch source...
~$ git clone http://review.coreboot.org/p/serialice
and build:
~$ cd serialice/qemu-0.15.x ~serialice/qemu-0.15.x$ . ./build.sh
To contribute to project, same guidelines apply to SerialICE as to coreboot.
3. Firing up SerialICE session
The commandline to invoke a SerialICE session should look something like this:
~/serialice/qemu-0.15.x/i386-softmmu/qemu -machine serialice --serialice /dev/ttyUSB0 -L ./mb_vendor_bios/
You should then see the serialice output start rolling on your console.
4. The mainboard script
In contrary to the single-file filter script "serialice.lua" the new filter implementation is split to several files under SerialICE/simba/.
This new file layout does not even try to be an all-in-one filter supporting every existing mainboard --- you need to add a file that describes the chipset on your target mainboard. This 'mainboard script' file has a pre-defined name and you see it printed at the beginning of the console output when SerialICE session is started.
A SerialICE session can run without a mainboard script file, but it can decode only those IO operations that have "default" or "semi-standard" locations in x86 architecture.
To get started, you could copy some of the existing mainboard files as the basis for your setup. Further development besides selecting from the already implemented chipset parts takes more in-depth understanding of the filter setup.
5. Filter stack in brief
An IO/MEM operation will first match a filter that claims the particular IO/MEM region. Active filters/regions are listed as RESOURCE lines in the log. Writes to PCI config space BAR registers will activate new RESOURCE entries.
A filter claiming the IO/MEM operation decides if the operation executes on the real target hardware, the QEMU platform, or neither. A filter optionally appends and/or removes lines in the output log.
What is said about IO/MEM operations here also applies to CPUID, RDMSR/WRMSR and PCI config space accesses.
Any comments are welcome. I'll continue with writing a tutorial that should explain the filter anatomy and how it is supposed to work.
Regards,
Kyösti
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Kyösti Mälkki