u-boot

mirror of https://github.com/u-boot/u-boot.git synced 2024-12-20 10:13:25 +08:00

History

Joe Hershberger d2eaec6006 net: Remove the bd* parameter from net stack functions This value is not used by the network stack and is available in the global data, so stop passing it around. For the one legacy function that still expects it (init op on old Ethernet drivers) pass in the global pointer version directly to avoid changing that interface. Signed-off-by: Joe Hershberger <joe.hershberger@ni.com> Reported-by: Simon Glass <sjg@chromium.org> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org> (Trival fix to remove an unneeded variable declaration in 4xx_enet.c)		2015-04-18 11:11:11 -06:00
..
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	Add GPL-2.0+ SPDX-License-Identifier to source files	2013-07-24 09:44:38 -04:00
api.c	Add GPL-2.0+ SPDX-License-Identifier to source files	2013-07-24 09:44:38 -04:00
Makefile	Makefile: descend into subdirectories only when CONFIG_API is defined	2013-11-25 10:41:54 -05:00
README	Coding Style cleanup; update CHANGELOG	2008-01-10 00:55:14 +01:00

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