On 2011-03-18, Stanislav Meduna <st...@meduna.org> wrote:
> On 18.03.2011 20:52, Grant Edwards wrote:
>
>> Is there any eCos API support that the HAL can use to provide either
>> random data or a unique id value to application or OS code?
>
> I don't know of any.
I've done some more grepping, but haven't found anything.
>> Both random values and UUID values are required for a lot of network
>> stuff. It's pretty common for hardware platforms to one or both,
>> there doesn't seem to be an eCos API to access it.
>
> This is a very good request.
Decent sources for unique IDs are probably a lot more common than
decent entropy sources, but it seems like something for which we need
an API. A UID can be pretty easily generated by hashing a few things
(CPU serial number, flash serial number, MAC addresses, etc.).
Generating entropy without hardware support is a lot harder.
> However, I don't think this belongs into the HAL - it's more a device
> driver semantics (see e.g. /dev/{u,}random on linux) and the
> cyg_io_lookup / cyg_io_read is everything one needs here.
>
> What the HAL could provide is an interface supplying a source of
> entropy
That's pretty much what I meant.
> - however, this is hard to do correctly especially on an embedded
> system that is often running in a quite deterministic environment.
Indeed. Even if it's not cryptographically strong, something to use
for for things like pseuro-random retry-backoff would be great.
--
Grant Edwards grant.b.edwards Yow! How many retured
at bricklayers from FLORIDA
gmail.com are out purchasing PENCIL
SHARPENERS right NOW??
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