u-boot/api
Christophe Leroy 907208c452 powerpc: Partialy restore core of mpc8xx
CS Systemes d'Information (CSSI) manufactures 8xx boards for
critical communication systems. Those boards have been
running U-Boot since 2010 and will have to be maintained
until at least 2027.

commit 5b8e76c35e
("powerpc, 8xx: remove support for 8xx") orphaned those boards
by removing support for the mpc8xx CPU.

This commit partially restores support for the 8xx, with the
following limitations:
- Restores support for MPC866 and MPC885 only
- Does not restore IDE, PCMCIA, I2C, USB
- Does not restore examples
- Does not restore POST
- Does not restore Ethernet on SCC
- Does not restore console on SCC
- Does not restore bedbug and kgdb support

As the 866 and 885 do not support the following features,
they are not restored either:
- VIDEO / LCD
- RTC clock

The CPM uCODE patch is not restored either, because:
- 866 and 885 already have support for I2C and SPI relocation
without a uCODE patch
- relocation of SMC, I2C or SPI is only needed for using SCCs
for Ethernet or QMC

The dynamic setup/calculation of clocks is removed, we
expect the target being use with the clock and PLPRCR register
defined in the configuration.
All the clock settings for 8xx prior to 866 is removed as
well as we now only support 866 and 885.

This code is mature and addresses mature boards. Therefore
all code enclosed in '#if 0/#endif' and '#if XX_DEBUG/#endif'
is unneeded.

The following files are not restored by this patch:

- arch/powerpc/cpu/mpc8xx/bedbug_860.c
- arch/powerpc/cpu/mpc8xx/fec.h
- arch/powerpc/cpu/mpc8xx/kgdb.S
- arch/powerpc/cpu/mpc8xx/plprcr_write.S
- arch/powerpc/cpu/mpc8xx/scc.c
- arch/powerpc/cpu/mpc8xx/upatch.c
- arch/powerpc/cpu/mpc8xx/video.c
- arch/powerpc/include/asm/status_led.h
- arch/powerpc/lib/ide.c
- arch/powerpc/lib/ide.h
- doc/README.MPC866
- drivers/pcmcia/mpc8xx_pcmcia.c
- drivers/rtc/mpc8xx.c
- drivers/usb/gadget/mpc8xx_udc.c
- drivers/video/mpc8xx_lcd.c
- examples/standalone/test_burst.c
- examples/standalone/test_burst.h
- examples/standalone/test_burst_lib.S
- examples/standalone/timer.c
- include/mpc823_lcd.h
- include/usb/mpc8xx_udc.h
- post/cpu/mpc8xx/Makefile
- post/cpu/mpc8xx/cache.c
- post/cpu/mpc8xx/cache_8xx.S
- post/cpu/mpc8xx/ether.c
- post/cpu/mpc8xx/spr.c
- post/cpu/mpc8xx/uart.c
- post/cpu/mpc8xx/usb.c
- post/cpu/mpc8xx/watchdog.c

Some of the restored files are not located in a proper location.
In order to keep traceability of the changes, they will be
moved to their correct location and moved to Kconfig in a
followup patch.

This patch also declares CSSI as point of contact for the update
of the 8xx platform, as those boards are the only ones still
being maintained on the 8xx area. A later patch will add
those boards to the tree.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
2017-07-08 15:55:26 -04:00
..
api.c api: Use hashtable function for API_env_enum 2017-01-20 09:15:24 -05:00
api_display.c Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_net.c api: Disable api_net when DM is used 2016-07-22 14:03:43 +02:00
api_platform-arm.c Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_platform-mips.c api: Add FreeBSD API support for MIPS platforms 2016-02-08 10:22:38 -05:00
api_platform-powerpc.c powerpc: Partialy restore core of mpc8xx 2017-07-08 15:55:26 -04:00
api_private.h Add GPL-2.0+ SPDX-License-Identifier to source files 2013-07-24 09:44:38 -04:00
api_storage.c api: Define a default mmc max device 2017-06-23 10:38:06 -04:00
Kconfig kconfig: Add API kconfig file 2017-02-08 15:56:31 -05:00
Makefile api: Add FreeBSD API support for MIPS platforms 2016-02-08 10:22:38 -05:00
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