[U-Boot] porting u-boot, few final questions

[Fabio Estevam]

On Mon, Nov 10, 2014 at 1:47 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Fabio Estevam,
>
> In message <CAOMZO5AiJtDt_CZrO6gzU=JiPp_2-etPiGFcK7ZhFhNNzxp3_A at mail.gmail.com> you wrote:
>>
>> > 1. How come setenv is not working in the board file? I tried setenv in
>> > different locations of board_early_init_f(), board_init(), board_late_init()
>> > and checkboard(), but it's not working. Did something change?
>>
>> Haven't tried it, but if this does not work, then it is a bug that
>> needs to be fixed. Do you have access to a mx53 qsb board? Does it
>> work there?
>
> Suffix _f trditionally means "running from flash", i. e. this is
> before relocation to RAM. Here we have usually only a read-ony data
> segment, no BSS at all, and only limted stack.  All complicated stuff
> like setenv is only supposed to be available after relocation.

Just tested on real hardware and the below change works:

--- a/board/freescale/mx53loco/mx53loco.c
+++ b/board/freescale/mx53loco/mx53loco.c
@@ -404,6 +404,12 @@ int board_late_init(void)
        return 0;
 }

+int misc_init_r(void)
+{
+       setenv("myvar", "123456");
+       return 0;
+}
+
 int checkboard(void)
 {
        puts("Board: MX53 LOCO\n");
diff --git a/include/configs/mx53loco.h b/include/configs/mx53loco.h
index a74508c..8f692d7 100644
--- a/include/configs/mx53loco.h
+++ b/include/configs/mx53loco.h
@@ -29,6 +29,7 @@

 #define CONFIG_BOARD_EARLY_INIT_F
 #define CONFIG_BOARD_LATE_INIT
+#define CONFIG_MISC_INIT_R
 #define CONFIG_MXC_GPIO
 #define CONFIG_REVISION_TAG

>
>> On mx6 we have several boards calling setenv from the board files.
>
> Actual behaviour is hardware-dependent, but it's better not to make
> any such guesses.

Yes, but not sure how a mx6 can differ from a mx5 in getting setenv to work.