FYI: I used put spd data in a stand alone C source code so that I can edit with vi directly.
unsigned char global_spd_data[256] = __attribute__ ((section("spd_data"))) { 0x??, 0x??, ... };
Note: I also put spd_data in the spd data section that is the end of my binary xloader code. I can easily edit with bvi editor too.
https://en.wikipedia.org/wiki/Serial_presence_detect
On Fri, Oct 23, 2015 at 11:35 AM, Aaron Durbin adurbin@google.com wrote:
This one's for Ron.
On Fri, Oct 23, 2015 at 10:32 AM, ron minnich rminnich@gmail.com wrote:
Build the tool in go. It's trivial. If you have an idea how it ought to
work
I can set it up in the playground in a few minutes.
ron
On Fri, Oct 23, 2015 at 8:24 AM Patrick Georgi pgeorgi@google.com
wrote:
Hi,
Some mainboards come with soldered-on memory without SPD ROM. For these, we carry the SPD data in coreboot.
Currently, they're stored in a hexdump format that is then converted to binary at build time. The various mechanisms of doing so fail on some platform or another:
- "echo -e -n $stuff" isn't well-liked by some shells (emits "e -n
$stuff")
- "printf '\x42'" isn't well-liked by some shells (or /usr/bin/printf
tools) that don't support hexadecimal formats
- "printf '\0377'" isn't well-liked by some non-conforming, but
existing
shells
- xxd -rg1 $file > $file.bin requires xxd, which comes with vim and
may just not exist
I see essentially two ways out of this, before we can start reducing duplication across the tree in that area: We could build our own tool to parse hex files and dump binary, or we could ship SPD data as binary from the start (and only have to concatenate them).
The second option has the appeal of being much simpler (and there isn't really a "preferred form" for editing SPD data that I'm aware of
- is there?), but looks icky at a glance because it's binary (but it's
really just as impenetrable as the equivalent hexdump).
So what do these files contain? Parameters (as in: facts) about the hardware's size, layout, and timing, and a bunch of vendor/model identifier strings.
So, is there a third option that I'm missing? Other opinions? Patrick -- Google Germany GmbH, ABC-Str. 19, 20354 Hamburg Registergericht und -nummer: Hamburg, HRB 86891, Sitz der Gesellschaft: Hamburg Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle
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-
Sheng-Liang Song