1 To enable this feature just define CONFIG_HWCONFIG in your board 2 config file. 3 4 This implements a simple hwconfig infrastructure: an 5 interface for software knobs to control hardware. 6 7 This a is very simple implementation, i.e. it is implemented 8 via the `hwconfig' environment variable. Later we could write 9 some "hwconfig <enable|disable|list>" commands, ncurses 10 interface for Award BIOS-like interface, and frame-buffer 11 interface for AMI GUI[1] BIOS-like interface with mouse 12 support[2]. 13 14 Current implementation details/limitations: 15 16 1. Doesn't support options dependencies and mutual exclusion. 17 We can implement this by integrating apt-get[3] into Das 18 U-Boot. But I haven't bothered yet. 19 20 2. Since we don't implement a hwconfig command, i.e. we're working 21 with the environment directly, there is no way to tell that 22 toggling a particular option will need a reboot to take 23 effect. So, for now it's advised to always reboot the 24 target after modifying the hwconfig variable. 25 26 3. We support hwconfig options with arguments. For example, 27 28 set hwconfig "dr_usb:mode=peripheral,phy_type=ulpi" 29 30 This selects three hwconfig options: 31 1. dr_usb - enable Dual-Role USB controller; 32 2. dr_usb_mode:peripheral - USB in Function mode; 33 3. dr_usb_phy_type:ulpi - USB should work with ULPI PHYs. 34 35 The purpose of this simple implementation is to refine the 36 internal API and then we can continue improving the user 37 experience by adding more mature interfaces, like a hwconfig 38 command with bells and whistles. Or not adding, if we feel 39 that the current interface fits people's needs. 40 41 [1] http://en.wikipedia.org/wiki/American_Megatrends 42 [2] Regarding ncurses and GUI with mouse support -- I'm just 43 kidding. 44 [3] The comment regarding apt-get is also a joke, meaning that 45 dependency tracking could be non-trivial. For example, for 46 enabling HW feature X we may need to disable Y, and turn Z 47 into reduced mode (like RMII-only interface for ethernet, 48 no MII). 49 50 It's quite trivial to implement simple cases though. 51
