u-boot/api
Stephen Warren 7c4213f6a5 block: pass block dev not num to read/write/erase()
This will allow the implementation to make use of data in the block_dev
structure beyond the base device number. This will be useful so that eMMC
block devices can encompass the HW partition ID rather than treating this
out-of-band. Equally, the existence of the priv field is crying out for
this patch to exist.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-01-13 21:05:18 -05:00
..
api.c Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_display.c Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_net.c net: Remove the bd* parameter from net stack functions 2015-04-18 11:11:11 -06:00
api_platform-arm.c Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_platform-powerpc.c powerpc: mpc8260: consolidate CONFIG_MPC8260 and CONFIG_8260 2014-03-07 10:59:06 -05:00
api_private.h Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_storage.c block: pass block dev not num to read/write/erase() 2016-01-13 21:05:18 -05:00
Makefile Makefile: descend into subdirectories only when CONFIG_API is defined 2013-11-25 10:41:54 -05:00
README

U-Boot machine/arch independent API for external apps
=====================================================

1.  Main assumptions

  - there is a single entry point (syscall) to the API

  - per current design the syscall is a C-callable function in the U-Boot
    text, which might evolve into a real syscall using machine exception trap
    once this initial version proves functional

  - the consumer app is responsible for producing appropriate context (call
    number and arguments)

  - upon entry, the syscall dispatches the call to other (existing) U-Boot
    functional areas like networking or storage operations

  - consumer application will recognize the API is available by searching
    a specified (assumed by convention) range of address space for the
    signature

  - the U-Boot integral part of the API is meant to be thin and non-intrusive,
    leaving as much processing as possible on the consumer application side,
    for example it doesn't keep states, but relies on hints from the app and
    so on

  - optional (CONFIG_API)


2. Calls

  - console related (getc, putc, tstc etc.)
  - system (reset, platform info)
  - time (delay, current)
  - env vars (enumerate all, get, set)
  - devices (enumerate all, open, close, read, write); currently two classes
    of devices are recognized and supported: network and storage (ide, scsi,
    usb etc.)


3. Structure overview

  - core API, integral part of U-Boot, mandatory
    - implements the single entry point (mimics UNIX syscall)

  - glue
    - entry point at the consumer side, allows to make syscall, mandatory
      part

    - helper conveniency wrappers so that consumer app does not have to use
      the syscall directly, but in a more friendly manner (a la libc calls),
      optional part

  - consumer application
    - calls directly, or leverages the provided glue mid-layer