Re: [Freeipmi-devel] FreeIPMI question

[Marty Rogers]

Anand Babu wrote:

> ,----[ Marty Rogers <address@hidden> ]
> | All,
> | 
> | I am attempting to adapt FreeIPMI to run on a controller to talk to
> | the BMC using IPMB.
> | 
> | My question is about how, or if, freeipmi handles "autonomous"
> | messages (such as Event messages I believe- they can come in any
> | time?)  Does a process ever sleep, waiting on a signal of some sort
> | from the system interface?  Or is there only a
> | send-a-message-wait-for-a-reply-then-get-out paradigm ?
> | 
> | (Presumably polling is always an option...)
> | 
> | If there's waiting/sleeping involved, briefly how is it implemented ?
> `----
> Yes can issue a blocking KCS read call on the BMC in a loop looking
> for Event messages.
>
> ssize_t
> ipmi_kcs_read (u_int16_t sms_io_base, 
>                         u_int8_t* bytes, u_int32_t bytes_len);
>
> Please share more info about your work. We would like to work with you
> closely. 
>
>  
So ipmi_kcs_cmd() writes a command and doesn't return until the response 
is received,
ipmi_kcs_write()  writes a command and returned immed., and 
ipmi_kcs_read() "hangs"
until "something" is received ?

If "yes", then the way to poll for unexpected/autonomous messages (Event 
Messages?)
is to call ipmi_kcs_read() in a loop?

My project has me implementing IPMI on essentially a "satellite 
controller" on the IPMB
bus (I2C bus), running Linux.  I've looked at OpenIPMI, modifying it's 
BT interface to
do I2C kernel calls instead of memory accesses (the BT interface 
protocol implements
seq. numbers, like IPMB), effectively becoming an IPMB interface.  I 
just pick an I2C
address around B0h-BEh, and xmit from LUN 0 (the IPMB interface is 
always LUN 0).

I'm not sure FreeIPMI can be modified similarly, but your thoughts would 
be most
welcome.  I would have to implement seq. number generation and matching.

martin rogers