OMAP Wireless Connectivity mac80211 compat wireless implementation Architecture

Scope

This section will explain the Compat Wireless Generation process and architecture.

Introduction

compat-wireless backports both the bluetooth and 802.11 subsystems down to older kernels. To be able to synchronize backporting the latest and greatest the linux-next.git tree is used as its main source for kernel updates. General Linux kernel compatibility is addressed through a general kernel compatibility tree, compat.git. compat-wireless then has its own tree for specific wireless compatibility.

Building Instructions

You will then need to checkout three trees to start hacking on compat-wireless:

git://github.com/TI-OpenLink/wl12xx.git
git://github.com/TI-OpenLink/compat.git
git://github.com/TI-OpenLink/compat-wireless.git

Clone the gits:

git clone git://github.com/TI-OpenLink/wl12xx.git
git clone git://github.com/TI-OpenLink/compat.git
git clone git://github.com/TI-OpenLink/compat-wireless.git

To update a git, get inside the directory that inclides the git and type:

git fetch origin

To point to specific commit_ID (for wl12xx.git only):

git reset --hard commit_ID 

wl12xx.git

The wl12xx.git tree brings all subsystems being worked on for the next kernel release into one tree. This means wl12xx will have what people today are working on for the 3.x kernel release.

compat.git

The compat git tree is a general kernel compatibility layer which can be shared among different compatibility projects, or drivers. compat-wireless is just one of the kernel compatibility projects using compat.git. compat.git builds a general compatibility module, compat, and any additional modules to let you get new general kernel updates from future kernels on your old kernels.

compat-wireless.git

Anything that is not general kernel compatibility but instead specific to 802.11 or bluetooth goes into compat-wireless.git


Now that we have the git trees, we need to point to them by exporting the following variables:

export GIT_TREE=/home/user/Projects/MAC80211/wl12xx
export GIT_COMPAT_TREE=/home/user/Projects/MAC80211/compat

Where:

• The GIT_TREE variable points to the wl12xx git previously downloaded.
• The GIT_COMPAT_TREE points to the compat git previously downloaded.

Now we need to run scripts/admin-refresh.sh in order to apply the compat-wireless-2.6 patches and update the Compat accordingly.

cd /home/user/Projects/MAC80211/compat-wireless

scripts/admin-refresh.sh

In general, you can update your local sources based on these wl12xx.git and compat.git trees:

scripts/admin-clean.sh   - Cleans the compat-wireless tree
scripts/admin-update.sh  - Updates compat-wireless with your git tree
scripts/admin-refresh.sh - Does the above two

Now we need to select the wl12xx. Switch to directory compat-wireless-2.6 and invoke:

scripts/driver-select wl12xx

Then, in order to compile the compat-wireless package you need to invoke:

make KLIB_BUILD=<your linux kernel version> KLIB=<your linux kernel version>

Deploy to rootfs

In order to install the Compat on the EVM you need to pick up the following kernel objects:

compat.ko         - located under (Compat-Wireless)/compat/
cfg80211.ko       - located under (Compat-Wireless)/net/wireless/
mac80211.ko       - located under (Compat-Wireless)/net/mac80211/
wl12xx.ko         - located under (Compat-Wireless)/drivers/net/wireless/wl12xx
wl12xx_sdio.ko    - located under (Compat-Wireless)/drivers/net/wireless/wl12xx

Those files should be copied to the rootfs in the following directories:

compat.ko         - located under /lib/modules/2.6.37/updates/compat
cfg80211.ko       - located under /lib/modules/2.6.37/updates/net/wireless
mac80211.ko       - located under /lib/modules/2.6.37/updates/net/mac80211
wl12xx.ko         - located under /lib/modules/2.6.37/updates/drivers/net/wireless/wl12xx
wl12xx_sdio.ko    - located under /lib/modules/2.6.37/updates/drivers/net/wireless/wl12xx

Now you need to reboot the EVM in order to run those kernel objects.