[U-Boot] what means the "CONFIG_SYS_USE_PPCENV" config setting?

[Robert P. J. Day]

  currently pawing my way through the mechanics of u-boot environment,
and noticed that a small number of boards support:

$ grep -r PPCENV *
common/env_embedded.c:#if defined(CONFIG_SYS_USE_PPCENV) && \
common/env_embedded.c:#  define __PPCENV__	__attribute__ ((section(".ppcenv")))
common/env_embedded.c:#  define __PPCENV__	/*XXX DO_NOT_DEL_THIS_COMMENT*/
common/env_embedded.c:#  define __PPCENV__	__attribute__ ((section(".text")))
common/env_embedded.c:env_t redundand_environment __PPCENV__ = {
include/configs/TQM823M.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM855L.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM866M.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM850L.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM860M.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM850M.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM862M.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM862L.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/inka4x0.h:#define CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM855M.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM860L.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/configs/TQM823L.h:#define	CONFIG_SYS_USE_PPCENV			/* Environment embedded in sect .ppcenv */
include/env_default.h:env_t environment __PPCENV__ = {
$

  what is the rationale for that small selection of boards to put
their environment in a separate section? if i keep reading, i'm sure
it will become obvious.

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
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