| To enable this feature just define CONFIG_HWCONFIG in your board | |
| config file. | |
| This implements a simple hwconfig infrastructure: an | |
| interface for software knobs to control hardware. | |
| This a is very simple implementation, i.e. it is implemented | |
| via the `hwconfig' environment variable. Later we could write | |
| some "hwconfig <enable|disable|list>" commands, ncurses | |
| interface for Award BIOS-like interface, and frame-buffer | |
| interface for AMI GUI[1] BIOS-like interface with mouse | |
| support[2]. | |
| Current implementation details/limitations: | |
| 1. Doesn't support options dependencies and mutual exclusion. | |
| We can implement this by integrating apt-get[3] into Das | |
| U-Boot. But I haven't bothered yet. | |
| 2. Since we don't implement a hwconfig command, i.e. we're working | |
| with the environement directly, there is no way to tell that | |
| toggling a particular option will need a reboot to take | |
| effect. So, for now it's advised to always reboot the | |
| target after modifying the hwconfig variable. | |
| 3. We support hwconfig options with arguments. For example, | |
| set hwconfig "dr_usb:mode=peripheral,phy_type=ulpi" | |
| This selects three hwconfig options: | |
| 1. dr_usb - enable Dual-Role USB controller; | |
| 2. dr_usb_mode:peripheral - USB in Function mode; | |
| 3. dr_usb_phy_type:ulpi - USB should work with ULPI PHYs. | |
| The purpose of this simple implementation is to refine the | |
| internal API and then we can continue improving the user | |
| experience by adding more mature interfaces, like a hwconfig | |
| command with bells and whistles. Or not adding, if we feel | |
| that the current interface fits people's needs. | |
| [1] http://en.wikipedia.org/wiki/American_Megatrends | |
| [2] Regarding ncurses and GUI with mouse support -- I'm just | |
| kidding. | |
| [3] The comment regarding apt-get is also a joke, meaning that | |
| dependency tracking could be non-trivial. For example, for | |
| enabling HW feature X we may need to disable Y, and turn Z | |
| into reduced mode (like RMII-only interface for ethernet, | |
| no MII). | |
| It's quite trivial to implement simple cases though. |