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| == Ideas for generic handling of devices == | | == Sections deserving their own page == |
| | | * [[User_talk:MrNuke/Block_Device_API]] |
| IMPORTANT! Feel free to edit this page to share your thoughts and ideas. This is the official MMC open brainstorming page.
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| === Proposal 1: Unified API === | |
| Chan is an IO channel.
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| This struct is used in Inferno and has been for a long time; so it works.
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| It's also in the opcodes somewhat like what we did for EMMC on ARM.
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| struct Dev
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| {
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| char* name;
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| void (*reset)(void);
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| void (*init)(void);
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| void (*shutdown)(void);
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| Chan* (*attach)(char*); /* tell the device you want to use it */
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| Walkqid* (*walk)(Chan*, Chan*, char**, int); /* walk to a name in the device's managed name space; return a handle */
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| int (*stat)(Chan*, uchar*, int); // status info
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| Chan* (*open)(Chan*, int); /* get access to a resource in the device name space */
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| void (*close)(Chan*); /* tell it you are done with whatever it is. */
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| long (*read)(Chan*, void*, long, vlong);
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| long (*write)(Chan*, void*, long, vlong);
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| void (*power)(int); /* power mgt: power(1) ? on, power (0) ? off */
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| };
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| ==== Questions ====
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| # Do we want to expose or hide the block nature of some devces (i.e. force reading multiples of blocksize, or allow reading any number of bytes, with no alignment requirement) ?
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| # How do we connect the dots, such that most of the details can be handled transparently ?
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| # How simple or complex do we want the API to be such that it can work in any stage (including bootblock, assuming some SRAM and a stack are available) ?
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| # Can we integrate this into '''libpayload''' such that the same sources can be used for both coreboot and libpayload ?
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| #* think "Device specfic storage drivers -> [*] Allwinner A10 MMC driver" in '''libpayload''' config
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| # More questions coming soon (TM)
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