| Message ID | CAOMZO5Cum=pEtGvOk3x1SrpuGSt=BreNGG7A8xhotFyJP41BJA@mail.gmail.com |
|---|---|
| State | Not Applicable |
| Headers | show |
Hi gents, On 11/10/2014 06:04 PM, Fabio Estevam wrote: > On Mon, Nov 10, 2014 at 1:47 PM, Wolfgang Denk <wd@denx.de> wrote: >> Dear Fabio Estevam, >> >> In message <CAOMZO5AiJtDt_CZrO6gzU=JiPp_2-etPiGFcK7ZhFhNNzxp3_A@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. Please correct me if I'm wrong, but setting env-vars shouldn't work before the environment is initialized. This initialization happens when the initr_env() is called according the order in init_sequence_r[]. @Dave - the easiest way to verify when your code (which tries to work with the env-vars) is executed and when the actual environment is initialized, is to enable debugging in lib/initcall.c:initcall_run_list(), see the pointers of the called functions and check them in the System.map. The env is initialized in the call tree below initr_env(), so your code should use the env after that. Regards, Nikolay
Update: my board_late_init() function wasn’t working because I defined BOARD_LATE_INIT instead of CONFIG_BOARD_LATE_INIT. Doh! Since arch/arm/lib/board.c file is being removed, and when CONFIG_SYS_GENERIC_BOARD is defined, we are now using… common/board_f.c (for pre-relocation init) common/board_r.c (for post-relocation init) So my board file sequence is (in order of calling sequence according to the above two files)… 1. board_early_init_f() – needed to setup my uart, otherwise early output is missed 2. checkboard() – print board info - still in flash 3. board_init() – says chipselects should be setup here – we are running from RAM now 4. initr_env() is called here 5. board_late_init() - Nikolay, appears you are correct, initr_env must be called first in order to use setenv. That’s why setenv didn’t work in board_early_init_f or checkboard or board_init. Fabio, your change worked when I use setenv in misc_init_r and helped me debug some issues. Thanks guys. Is there a doc or a good read that explains which init functions are necessary for what? Or which ones should be used for “proper” design? I’m sure I’ll be back with more questions real soon. :) -- View this message in context: http://u-boot.10912.n7.nabble.com/porting-u-boot-MMU-question-tp194761p195451.html Sent from the U-Boot mailing list archive at Nabble.com.
So I am having another issue probably more related to computer science fundamentals. I have a global variable boot_dev defined in my board file like so... I define boot_device in arch/arm/include/asm/arch-mx5/sys_proto.h like this… Now, boot_dev returns the correct value in checkboard(), but returns 0 when called from any other function. board_early_init_f() – we set boot_dev checkboard() – we print it and works fine, prints 6 (SD_BOOT) board_init() – prints 0 here board_late_init() - prints 0 here So…boot_dev is not set anywhere else except board_early_init_f(), then it prints ok in checkboard(), but then it gets set to 0 somehow. Anyone know why this could be? Checkboard() runs from flash and the others run from RAM. Can that have something to do with it? -- View this message in context: http://u-boot.10912.n7.nabble.com/porting-u-boot-MMU-question-tp194761p195488.html Sent from the U-Boot mailing list archive at Nabble.com.
So the issues of the variables changing were due to me initializing everything in board_early_init_f(). I moved everything out of it except uart setup. If I setup the uart in board_init() instead of board_early_init_f() then the early cpu info stuff is missed. I guess there’s an opportunity for improvement there. I still have a question pertaining to the changing variables though. It has to do with pre and post relocation. Variables declared in functions pre-reloc will be different when used in functions post-reloc. For instance. If I set a variable in board_early_init_f() and then, without changing it, print it in board_late_init() then it will be different. So my question is how can I get around this? This is where I’m stuck… I’m trying to write the reset cause to SRAM in board_late_init(). The reset cause is printed early by default when defining CONFIG_DISPLAY_CPUINFO in the header file. When I access the register in board_late_init() it prints 0, which is wrong. I tried… and this(which is what arch/arm/imx-common/cpu.c uses to print reset cause)… All return 0 when called in board_late_init() even though at startup the correct reset cause is displayed, but I have to write it to SRAM later on. And by that time it's 0. I think this has to do with what Wolfgang said about ds, bss, and stack, but if someone can shed some light that would be great. :) Thanks -- View this message in context: http://u-boot.10912.n7.nabble.com/porting-u-boot-MMU-question-tp194761p195618.html Sent from the U-Boot mailing list archive at Nabble.com.
--- 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