Re: [U-Boot] [PATCH 1/1] OMAP3: igep00x0: allow booting with a FDT from MMC

On Mon, Jul 15, 2013 at 9:43 AM, Enric Balletbo Serra eballetbo@gmail.com wrote:

Hi Javier,

Hi Enric,

Thanks a lot for your feedback.

2013/7/14 Javier Martinez Canillas javier@dowhile0.org:

...

IGEP boards now have Device Tree support in the mainline kernel. To boot an IGEP board using a DT, a uEnv.txt plain text file could be used to define a custom uenvcmd that will be run by the default boot command.

It is more convenient to change the default boot command to allow loading a FDT if it is stored in a uSD/MMC partition. If no FDT is found then the command behaves just as it used so this change won't break existing setup for current users.

Signed-off-by: Javier Martinez Canillas javier.martinez@collabora.co.uk

board/isee/igep00x0/igep00x0.c | 14 ++++++++++++++ include/configs/igep00x0.h | 9 +++++++++ 2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/board/isee/igep00x0/igep00x0.c b/board/isee/igep00x0/igep00x0.c index 0d4679d..fdd2773 100644 --- a/board/isee/igep00x0/igep00x0.c +++ b/board/isee/igep00x0/igep00x0.c @@ -154,6 +154,18 @@ int board_mmc_init(bd_t *bis) } #endif

+void set_fdt(void) +{

•   switch (gd->bd->bi_arch_number) {
  

•   case MACH_TYPE_IGEP0020:
  

•           setenv("fdtfile", "omap3-igep0020.dtb");
  

•           break;
  

•   case MACH_TYPE_IGEP0030:
  

•           setenv("fdtfile", "omap3-igep0030.dtb");
  

•           break;
  

•   }
  

+}

/*

• Routine: misc_init_r
• Description: Configure board specific parts

@@ -166,6 +178,8 @@ int misc_init_r(void)

    dieid_num_r();

•   set_fdt();
  

•   return 0;
  

}

diff --git a/include/configs/igep00x0.h b/include/configs/igep00x0.h index 1d8090b..72752af 100644 --- a/include/configs/igep00x0.h +++ b/include/configs/igep00x0.h @@ -149,6 +149,7 @@ #define CONFIG_EXTRA_ENV_SETTINGS \ "usbtty=cdc_acm\0" \ "loadaddr=0x82000000\0" \

•   "fdtaddr=0x81600000\0" \
    "usbtty=cdc_acm\0" \
    "console=ttyO2,115200n8\0" \
    "mpurate=auto\0" \
  

@@ -180,9 +181,12 @@ "importbootenv=echo Importing environment from mmc ...; " \ "env import -t $loadaddr $filesize\0" \ "loaduimage=fatload mmc ${mmcdev} ${loadaddr} uImage\0" \

•   "loadfdt=fatload mmc ${mmcdev} ${fdtaddr} ${fdtfile}\0" \
    "mmcboot=echo Booting from mmc ...; " \
            "run mmcargs; " \
            "bootm ${loadaddr}\0" \
  

•   "mmcbootfdt=echo Booting with DT from mmc ...; " \
  

•           "bootm ${loadaddr} - ${fdtaddr}\0" \
    "nandboot=echo Booting from onenand ...; " \
            "run nandargs; " \
            "onenand read ${loadaddr} 280000 400000; " \
  

@@ -199,6 +203,11 @@ "run uenvcmd;" \ "fi;" \ "if run loaduimage; then " \

•                   "if test -n $fdtfile; then " \
  

•                           "if run loadfdt; then " \
  

•                                   "run mmcbootfdt;" \
  

•                           "fi;" \
  

•                   "fi;" \
                    "run mmcboot;" \
            "fi;" \
    "fi;" \
  

-- 1.7.7.6

As merge window is closed, I think we have time to discuss a bit more this patch before sending for next merge window. I think it's time to redefine the default boot arguments for all IGEP boards and unify as possible the bootargs for IGEP0020, IGEP0030, IGEP0032 and IGEP0033.

Yes, I like the idea to redefine the default boot arguments. I just have been doing minor changes in the past like using ttyO for console, using EXT4 as mmcrootfstype, etc. But I agree that a major rethink will be good to make it more usable.

I made also some work in this line, but is not finished yet. We can send a the patch series for next merge window. These are the things that I think the patches should have.

1. Enable the use of CMD_EXT4, CMD_FS_GENERIC and zImage. https://github.com/eballetbo/u-boot/commit/38036e80a66f266f2c3fae82906c5c46a... As uImage is deprecated we should use zImages.

+1

2. Add support for Flattened Device Tree.
    For IGEP0033
       https://github.com/eballetbo/u-boot/commit/46ddafddc5bb6968190848d273b9ca8fbbd120de
    For IGEP0020/30/32
       Your patch

Note that I made some modifications on where the zImage and the DTB file is located. MLO and u-boot.img are from boot partition, and zImage and dtb file are from rootfs partition (/boot/ directory). What do you think about this ?

I'm not so fond in using /boot from the rootfs partition instead of a boot partition for two reasons:

1- It leaks boot information to the distro and makes the /boot directory content different for each board 2- It forces to use the same filesystem type for both the boot partition and rootfs or at least constraint to filesytems supported by U-Boot instead allowing to use any file system that is supported by Linux.

Basically I want my rootfs to be board agnostic and be able to use it with different boards. If IGEP boards use this scheme then I won't be able to let's say use XFS for my rootfs (this is not a real example just making a point).

In my setups I don't even mount the boot partition in /boot. /boot is just a directory that contains a vmlinuz, used defconfig, etc just like in any other distro and I I mount the boot partition in another directory only to update the uImage that is generated with mkimage from the vmlinuz in /boot.

3. Boot from NAND using a ubifs
         https://github.com/eballetbo/u-boot/commit/ebd8ab99b02ccbf08b4d50c60107b04c8129a8dd
    I think is better use ubifs instead of jffs2, also note that

the zImage and the dtb are from rootfs partition using the ubifsload.

+1 besides my previous comments about using ${bootdir}/${bootfile}

More ideas, comments ...

I think we should change the name of the config files to be soc_board, for example igep00x0.h should be called omap3_igep00x0.h and am335x_igep0033.h.

I noticed in the past that some SoC wide changes were missed for IGEP boards because probably people doing the change searched for include/configs/omap3_*

I would like that the bootargs betwen IGEP0020/30/32 and IGEP0033 were as similar as possible.

+1

Best regards,

Enric

Thanks a lot and best regards, Javier