On Sat, 2016-06-04 at 08:06 +0200, Boris Brezillon wrote: > On Fri, 03 Jun 2016 20:08:49 -0500 > Scott Wood <[email protected]> wrote: > > > This doesn't work. CONFIG_SPL_NAND_U_BOOT_OFFS will always be defined > > when SPL is defined, and the user will be forced to enter a value before > > kconfig will continue (or kconfig will error out in an automated build). > > Yes, CONFIG_SPL_NAND_U_BOOT_OFFS will always be defined, but won't be > used if CONFIG_SYS_NAND_U_BOOT_OFFS is defined in the config header > file. > And for the "user will forced to enter a value before Kconfig > continue" comment, we could just have > > config SPL_NAND_U_BOOT_OFFS > hex "Location in NAND to read U-Boot from" > default 0x8000 if NAND_SUNXI > default 0x0 > ...
If you do that, then that zero will override CONFIG_SYS_NAND_U_BOOT_OFFS from the header. > > If you want to do this there needs to be a separate bool config that > > controls whether the hex config exists. > > I can add an extra Kconfig option, but is it really necessary: > if people are relying on it they will choose a valid value, and leave > it to 0 otherwise. > It's just a detail, so I'm fine adding this extra option if you think > it's really useful. Zero *is* a valid value. Several boards already have that value for this symbol. Even if that weren't the case, we want a mechanism for migrating from header value to kconfig value that works for more than just this one specific symbol. > > > And there'd be no need to rename hex symbol. > > Well, functionally there's no problem keeping the existing SYS_ prefix > if we add this extra option to activate the U_OFFS config in Kconfig, > but I'm not sure this is a good idea to reuse config header names in > Kconfig. > > And what happens if the user enabled this option (some like to enable > everything :-)) and CONFIG_SYS_NAND_U_BOOT_OFFS is also defined in the > board config header? Then the build fails with a redefined symbol, and the user learns their lesson. :-) The "SYS" in CONFIG_SYS means it's not a user-tunable knob. From README: > There are two classes of configuration variables: > > * Configuration _OPTIONS_: > These are selectable by the user and have names beginning with > "CONFIG_". > > * Configuration _SETTINGS_: > These depend on the hardware etc. and should not be meddled with if > you don't know what you're doing; they have names beginning with > "CONFIG_SYS_". -Scott _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
