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