Re: [PATCH 07/12] rockchip: puma-rk3399: load environment from same medium as one used to load U-Boot proper

[Quentin Schulz <quentin.schulz@theobroma-systems.com>]

Hi Kever,

On 9/4/22 13:49, Kever Yang wrote:
> Hi Quentin,
> 
> The Kconfig from env/Kconfig
> 
> config ENV_IS_NOWHERE
>          bool "Environment is not stored"
>          default y if !ENV_IS_IN_EEPROM && !ENV_IS_IN_EXT4 && \
>                       !ENV_IS_IN_FAT && !ENV_IS_IN_FLASH && \
>                       !ENV_IS_IN_MMC && !ENV_IS_IN_NAND && \
>                       !ENV_IS_IN_NVRAM && !ENV_IS_IN_ONENAND && \
>                       !ENV_IS_IN_REMOTE && !ENV_IS_IN_SPI_FLASH && \
>                       !ENV_IS_IN_UBI
> 
> I think the logic is the env parameter is stored on some kind of 
> storage, or NOWHERE.
> 

It's *default* to yes if none is defined. It's not a requirement.

> And what you want to do is to load from the same medium as SPL boot 
> device(location of U-Boot proper),
> 
> this could not be NOWHERE.
> 

This can be nowhere in case the proper config option is not selected. 
E.g. we're booting from SPI-NOR but the ENV_IS_IN_SPI_FLASH is not set. 
How does one handle this scenario? Since we don't want fallbacks, it 
needs to be "nowhere". What you're suggesting is to let the user run a 
broken build and have it cryptically crash with the following error:

initcall sequence 00000000002866c0 failed at call 0000000000256b34 (err=-19)

Instead, I suggest to more gracefully error out at runtime by letting 
the user know that the option is not compiled in but U-Boot is still usable.

If you have another way to forbid fallbacks but not crash U-Boot in case 
the option is not selected, let me know.

Cheers,
Quentin
> 
> Thanks,
> 
> - Kever
> 
> On 2022/9/1 21:13, Quentin Schulz wrote:
>> Hi Kever
>>
>> On 9/1/22 15:03, Kever Yang wrote:
>>> Hi Quentin,
>>>
>>> On 2022/7/23 00:06, Quentin Schulz wrote:
>>>> From: Quentin Schulz <quentin.schulz@theobroma-systems.com>
>>>>
>>>> Chances are when one boots U-Boot proper from a given storage medium,
>>>> they want the same medium to be used to load and store the environment.
>>>>
>>>> This basically allows to have completely separate U-Boot 
>>>> (TPL/SPL/U-Boot
>>>> proper/environment) per storage medium which is convenient when working
>>>> with recovery from SD-Card as one would just need to insert a properly
>>>> configured SD-Card into the device to have access to their whole debug
>>>> setup.
>>>>
>>>> No fallback mechanism is provided as to not dirty other storage medium
>>>> environment by mistake. However, since arch_env_get_location() is 
>>>> called
>>>> by env_init() which is part of the pre-relocation process, a valid,
>>>> non-ENVL_UNKNOWN, value shall be returned otherwise the relocation 
>>>> fails
>>>> with the following message:
>>>> initcall sequence 00000000002866c0 failed at call 0000000000256b34 
>>>> (err=-19)
>>>>
>>>> This valid, non-ENVL_UNKNOWN, value is ENVL_NOWHERE which requires to
>>>> always select CONFIG_ENV_IS_NOWHERE otherwise this work-around does not
>>>> work.
>>>>
>>>> Cc: Quentin Schulz <foss+uboot@0leil.net>
>>>> Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
>>>> ---
>>>>
>>>> Depends on
>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__lore.kernel.org_u-2Dboot_20220715151552.953654-2D1-2Dfoss-2Buboot-400leil.net_&d=DwIDaQ&c=_sEr5x9kUWhuk4_nFwjJtA&r=LYjLexDn7rXIzVmkNPvw5ymA1XTSqHGq8yBP6m6qZZ4njZguQhZhkI_-172IIy1t&m=TZndtGz1ePTd2Il6YcEjqzo9oXv73RCWHIRVSiFVsnp2OzyCJEDzZ2KPz56AcWdn&s=wgEMbr3EjeCtvcWU_UoXqNOwQulaVN-0Qb2yL2ysaOs&e= https://urldefense.proofpoint.com/v2/url?u=https-3A__lore.kernel.org_u-2Dboot_20220715151552.953654-2D2-2Dfoss-2Buboot-400leil.net_&d=DwIDaQ&c=_sEr5x9kUWhuk4_nFwjJtA&r=LYjLexDn7rXIzVmkNPvw5ymA1XTSqHGq8yBP6m6qZZ4njZguQhZhkI_-172IIy1t&m=TZndtGz1ePTd2Il6YcEjqzo9oXv73RCWHIRVSiFVsnp2OzyCJEDzZ2KPz56AcWdn&s=PKwYBMB7r8ekIPV1ZG7xkj7vF60YNFlYXQRrvaVgJR8&e=
>>>>   .../puma_rk3399/puma-rk3399.c                 | 37 
>>>> +++++++++++++++++++
>>>>   configs/puma-rk3399_defconfig                 |  1 +
>>>>   2 files changed, 38 insertions(+)
>>>>
>>>> diff --git a/board/theobroma-systems/puma_rk3399/puma-rk3399.c 
>>>> b/board/theobroma-systems/puma_rk3399/puma-rk3399.c
>>>> index 5e5e58c88e..7ef4bac24b 100644
>>>> --- a/board/theobroma-systems/puma_rk3399/puma-rk3399.c
>>>> +++ b/board/theobroma-systems/puma_rk3399/puma-rk3399.c
>>>> @@ -6,6 +6,7 @@
>>>>   #include <common.h>
>>>>   #include <dm.h>
>>>>   #include <env.h>
>>>> +#include <env_internal.h>
>>>>   #include <init.h>
>>>>   #include <log.h>
>>>>   #include <misc.h>
>>>> @@ -135,6 +136,42 @@ int mmc_get_env_dev(void)
>>>>       return CONFIG_SYS_MMC_ENV_DEV;
>>>>   }
>>>> +#if !IS_ENABLED(CONFIG_ENV_IS_NOWHERE)
>>>> +#error Please enable CONFIG_ENV_IS_NOWHERE
>>>> +#endif
>>>> +
>>>> +enum env_location arch_env_get_location(enum env_operation op, int 
>>>> prio)
>>>> +{
>>>> +    const char *boot_device =
>>>> +        ofnode_read_chosen_string("u-boot,spl-boot-device");
>>>> +
>>>> +    if (prio > 0)
>>>> +        return ENVL_UNKNOWN;
>>>> +
>>>> +    if (!boot_device) {
>>>> +        debug("%s: /chosen/u-boot,spl-boot-device not set\n",
>>>> +              __func__);
>>>> +        return ENVL_NOWHERE;
>>>> +    }
>>>> +
>>>> +    debug("%s: booted from %s\n", __func__, boot_device);
>>>> +
>>>> +    if (IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH) &&
>>>> +        !strcmp(boot_device, "/spi@ff1d0000/flash@0"))
>>>> +        return ENVL_SPI_FLASH;
>>>> +
>>>> +    if (IS_ENABLED(CONFIG_ENV_IS_IN_MMC) &&
>>>> +        (!strcmp(boot_device, "/mmc@fe320000") ||
>>>> +         !strcmp(boot_device, "/mmc@fe330000")))
>>>> +        return ENVL_MMC;
>>>> +
>>>> +    printf("%s: No environment available: booted from %s but U-Boot "
>>>> +           "config does not allow loading environment from it.",
>>>> +           __func__, boot_device);
>>>> +
>>>> +    return ENVL_NOWHERE;
>>>> +}
>>>> +
>>>>   int misc_init_r(void)
>>>>   {
>>>>       const u32 cpuid_offset = 0x7;
>>>> diff --git a/configs/puma-rk3399_defconfig 
>>>> b/configs/puma-rk3399_defconfig
>>>> index 87d7e4f57c..e218532d70 100644
>>>> --- a/configs/puma-rk3399_defconfig
>>>> +++ b/configs/puma-rk3399_defconfig
>>>> @@ -44,6 +44,7 @@ CONFIG_SPL_OF_CONTROL=y
>>>>   CONFIG_OF_LIVE=y
>>>>   CONFIG_OF_SPL_REMOVE_PROPS="interrupt-parent assigned-clocks 
>>>> assigned-clock-rates assigned-clock-parents"
>>>>   CONFIG_ENV_OVERWRITE=y
>>>> +CONFIG_ENV_IS_NOWHERE=y
>>>
>>> This option is conflict with CONFIG_ENV_IS_IN_MMC,  please check 
>>> again where should be this board get the env.
>>>
>>
>> I created the defconfig with make savedefconfig, so if you're talking 
>> about KConfig conflict, that is incorrect, there is no conflict.
>>
>> If you're talking about something else, please clarify because I don't 
>> see the issue right now.
>>
>> Cheers,
>> Quentin