u-boot/api
Simon Glass ce30e3ff1e scsi: Drop CONFIG_SYS_SCSI_MAX_DEVICE
This is defined based on two other CONFIGs for all boards except sandbox
and durian.

For sandbox the value does not matter. For durian the value seems
excessive.

Drop the option completely, to simplify configuration and reduce the
number of things we need to convert to Kconfig.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
2022-02-09 09:16:48 -05:00
..
api.c common: board_r: Drop initr_api wrapper 2021-01-15 14:36:12 -05:00
api_display.c common: Drop log.h from common header 2020-05-18 21:19:18 -04:00
api_net.c SPDX: Convert all of our single license tags to Linux Kernel style 2018-05-07 09:34:12 -04:00
api_platform-arm.c SPDX: Convert all of our single license tags to Linux Kernel style 2018-05-07 09:34:12 -04:00
api_platform-mips.c global: Move from bi_memstart/memsize -> gd->ram_base/ram_size 2020-08-26 09:19:34 +02:00
api_platform-powerpc.c global: Move from bi_memstart/memsize -> gd->ram_base/ram_size 2020-08-26 09:19:34 +02:00
api_private.h common: board_r: Drop initr_api wrapper 2021-01-15 14:36:12 -05:00
api_storage.c scsi: Drop CONFIG_SYS_SCSI_MAX_DEVICE 2022-02-09 09:16:48 -05:00
Kconfig Kconfig: Remove all default n/no options 2021-08-31 17:47:49 -04:00
Makefile SPDX: Convert all of our single license tags to Linux Kernel style 2018-05-07 09:34:12 -04:00
README Coding Style cleanup; update CHANGELOG 2008-01-10 00:55:14 +01:00

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