=== Week -1: Modify JMicron driver, RX offloading ===
=== May 2nd to May 12th ===

== Chanloading with undionly image ==
Stefanha pointed out that I should try if JMicron driver can be chanloaded like: gPXE(jme driver)->gPXE(UNDI driver). Due to the UNDI interface would trigger .irq() function of net_device_operations.

First I spend a lot of time trying to figure out why chainloading with: syslinux->jme.lkrm->undionly.kpxe keeps crash(reboot) after some actions.

After a few tests, I found out that:
  * syslinux->gPXE(jme.lkrm)->undionly.kkpxe
  * Vendor PXE->gPXE(jme.pxe)->undionly.kkpxe
  * Vendor PXE->gPXE(jme.kpxe)->undionly.kkpxe

All worked fine. So I guess that it's an issue with the chainloading processes, instead of in-correct driver implement.

== Implement RX checksum offloading ==
Testing results can be found in this note: [[soc:2010:cooldavid:notes:benchmark|TCP Window Size and RX Csum Offload Benchmark]]

== Modify JMicron driver according to stefanha suggestions ==
  - jme_process_receive() isn't using a read memory barrier.
  - Allocate/Free Ring buffers on open/close.
  - Using jme_free_?x_resources() for allocation fail recover.
  - Simply use struct io_buffer, instead of jme_buffer_info.
  - There is no need to discard pending TX buffers.
  - extra memset in probe.
  - Ring size tune, performance test.

Detailed modifications can reference the [[http://git.etherboot.org/?p=people/cooldavid/gpxe.git;a=shortlog;h=refs/heads/jme_driver_bak|jme_driver_bak branch of my git tree]].