[U-Boot] [PATCH 1/2] armv8: calculate __bss_size in u-boot-spl.lds

[U-Boot] [PATCH 1/2] armv8: calculate __bss_size in u-boot-spl.lds

[Oded Gabbay]

This patch adds a missing __bss_size symbol to the default armv8
u-boot-spl.lds file.
Makefile.spl relies on __bss_size to be present when it creates the SPL
image. It uses that symbol to create a pad file that will be used to place
the dtb after the bss section.
In ARMv8 default u-boot-spl.lds, __bss_size was missing and therefore, the
pad file was always 0. As a result, the dtb was placed after
_image_binary_end, which caused a failure when loading it inside the SPL.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
---
 arch/arm/cpu/armv8/u-boot-spl.lds | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
index cc427c3..e7799cc 100644
--- a/arch/arm/cpu/armv8/u-boot-spl.lds
+++ b/arch/arm/cpu/armv8/u-boot-spl.lds
@@ -70,6 +70,7 @@ SECTIONS
 		KEEP(*(.__bss_end));
 	} >.sdram
 
+	__bss_size = __bss_end - _image_binary_end;
 	/DISCARD/ : { *(.dynsym) }
 	/DISCARD/ : { *(.dynstr*) }
 	/DISCARD/ : { *(.dynamic*) }
-- 
2.7.4

[U-Boot] [PATCH 2/2] armv8: add asserts of sizes to u-boot-spl.lds

[Oded Gabbay]

This patch copies from arm u-boot-spl.lds some asserts that check that the
size of the SPL image and BSS doesn't violate their max size.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
---
 arch/arm/cpu/armv8/u-boot-spl.lds | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
index e7799cc..0876a94 100644
--- a/arch/arm/cpu/armv8/u-boot-spl.lds
+++ b/arch/arm/cpu/armv8/u-boot-spl.lds
@@ -78,3 +78,22 @@ SECTIONS
 	/DISCARD/ : { *(.interp*) }
 	/DISCARD/ : { *(.gnu*) }
 }
+
+#if defined(CONFIG_SPL_MAX_SIZE)
+ASSERT(__image_copy_end - __image_copy_start < (CONFIG_SPL_MAX_SIZE), \
+	"SPL image too big");
+#endif
+
+#if defined(CONFIG_SPL_BSS_MAX_SIZE) && defined(CONFIG_SPL_MAX_FOOTPRINT)
+ASSERT(0, "CONFIG_SPL_BSS_MAX_SIZE and CONFIG_SPL_MAX_FOOTPRINT must not be defined together");
+#endif
+
+#if defined(CONFIG_SPL_BSS_MAX_SIZE)
+ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
+	"SPL image BSS too big");
+#endif
+
+#if defined(CONFIG_SPL_MAX_FOOTPRINT)
+ASSERT(__bss_end - _start < (CONFIG_SPL_MAX_FOOTPRINT), \
+	"SPL image plus BSS too big");
+#endif
-- 
2.7.4

[U-Boot] [PATCH 2/2] armv8: add asserts of sizes to u-boot-spl.lds

[Tom Rini]

On Mon, Dec 26, 2016 at 04:20:41PM +0200, Oded Gabbay wrote:

> This patch copies from arm u-boot-spl.lds some asserts that check that the
> size of the SPL image and BSS doesn't violate their max size.
> 
> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>

This shows a few problems with the uniphier platforms so I'm not
applying this currently.  Masahiro, can you take a look please?  Thanks!
https://travis-ci.org/trini/u-boot/jobs/190080917

-- 
Tom
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[U-Boot] [PATCH 2/2] armv8: add asserts of sizes to u-boot-spl.lds

[Masahiro Yamada]

2016-12-26 23:20 GMT+09:00 Oded Gabbay <oded.gabbay@gmail.com>:
> This patch copies from arm u-boot-spl.lds some asserts that check that the
> size of the SPL image and BSS doesn't violate their max size.
>
> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> ---
>  arch/arm/cpu/armv8/u-boot-spl.lds | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
> index e7799cc..0876a94 100644
> --- a/arch/arm/cpu/armv8/u-boot-spl.lds
> +++ b/arch/arm/cpu/armv8/u-boot-spl.lds
> @@ -78,3 +78,22 @@ SECTIONS
>         /DISCARD/ : { *(.interp*) }
>         /DISCARD/ : { *(.gnu*) }
>  }
> +
> +#if defined(CONFIG_SPL_MAX_SIZE)
> +ASSERT(__image_copy_end - __image_copy_start < (CONFIG_SPL_MAX_SIZE), \
> +       "SPL image too big");
> +#endif
> +
> +#if defined(CONFIG_SPL_BSS_MAX_SIZE) && defined(CONFIG_SPL_MAX_FOOTPRINT)
> +ASSERT(0, "CONFIG_SPL_BSS_MAX_SIZE and CONFIG_SPL_MAX_FOOTPRINT must not be defined together");
> +#endif
> +
> +#if defined(CONFIG_SPL_BSS_MAX_SIZE)
> +ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
> +       "SPL image BSS too big");
> +#endif
> +
> +#if defined(CONFIG_SPL_MAX_FOOTPRINT)
> +ASSERT(__bss_end - _start < (CONFIG_SPL_MAX_FOOTPRINT), \
> +       "SPL image plus BSS too big");
> +#endif
> --
> 2.7.4
>

This patch is wrong in multiple ways.



See the top lines of this file.

MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE,
         LENGTH = CONFIG_SPL_MAX_SIZE }
MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR,
         LENGTH = CONFIG_SPL_BSS_MAX_SIZE }

This means CONFIG_SPL_BSS_MAX_SIZE must always be defined.




Your code

> +#if defined(CONFIG_SPL_BSS_MAX_SIZE) && defined(CONFIG_SPL_MAX_FOOTPRINT)
> +ASSERT(0, "CONFIG_SPL_BSS_MAX_SIZE and CONFIG_SPL_MAX_FOOTPRINT must not be defined together");
> +#endif

... means CONFIG_SPL_BSS_MAX_FOOTPRINT can never be defined.


As a result,

> +#if defined(CONFIG_SPL_BSS_MAX_SIZE)
> +ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
> +       "SPL image BSS too big");
> +#endif

the ifdef is always true, so meaningless.

> +ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
> +       "SPL image BSS too big");

is already size-checked by the following:

MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR,
         LENGTH = CONFIG_SPL_BSS_MAX_SIZE }


so, meaningless.


> +#if defined(CONFIG_SPL_MAX_FOOTPRINT)
> +ASSERT(__bss_end - _start < (CONFIG_SPL_MAX_FOOTPRINT), \
> +       "SPL image plus BSS too big");
> +#endif

This code is never enabled.



-- 
Best Regards
Masahiro Yamada

[U-Boot] [PATCH 2/2] armv8: add asserts of sizes to u-boot-spl.lds

[Oded Gabbay]

On Tue, Jan 17, 2017 at 9:55 AM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> 2016-12-26 23:20 GMT+09:00 Oded Gabbay <oded.gabbay@gmail.com>:
>> This patch copies from arm u-boot-spl.lds some asserts that check that the
>> size of the SPL image and BSS doesn't violate their max size.
>>
>> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
>> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
>> ---
>>  arch/arm/cpu/armv8/u-boot-spl.lds | 19 +++++++++++++++++++
>>  1 file changed, 19 insertions(+)
>>
>> diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
>> index e7799cc..0876a94 100644
>> --- a/arch/arm/cpu/armv8/u-boot-spl.lds
>> +++ b/arch/arm/cpu/armv8/u-boot-spl.lds
>> @@ -78,3 +78,22 @@ SECTIONS
>>         /DISCARD/ : { *(.interp*) }
>>         /DISCARD/ : { *(.gnu*) }
>>  }
>> +
>> +#if defined(CONFIG_SPL_MAX_SIZE)
>> +ASSERT(__image_copy_end - __image_copy_start < (CONFIG_SPL_MAX_SIZE), \
>> +       "SPL image too big");
>> +#endif
>> +
>> +#if defined(CONFIG_SPL_BSS_MAX_SIZE) && defined(CONFIG_SPL_MAX_FOOTPRINT)
>> +ASSERT(0, "CONFIG_SPL_BSS_MAX_SIZE and CONFIG_SPL_MAX_FOOTPRINT must not be defined together");
>> +#endif
>> +
>> +#if defined(CONFIG_SPL_BSS_MAX_SIZE)
>> +ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
>> +       "SPL image BSS too big");
>> +#endif
>> +
>> +#if defined(CONFIG_SPL_MAX_FOOTPRINT)
>> +ASSERT(__bss_end - _start < (CONFIG_SPL_MAX_FOOTPRINT), \
>> +       "SPL image plus BSS too big");
>> +#endif
>> --
>> 2.7.4
>>
>
> This patch is wrong in multiple ways.
>
>
>
> See the top lines of this file.
>
> MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE,
>          LENGTH = CONFIG_SPL_MAX_SIZE }
> MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR,
>          LENGTH = CONFIG_SPL_BSS_MAX_SIZE }
>
> This means CONFIG_SPL_BSS_MAX_SIZE must always be defined.
>
>
>
>
> Your code
>
>> +#if defined(CONFIG_SPL_BSS_MAX_SIZE) && defined(CONFIG_SPL_MAX_FOOTPRINT)
>> +ASSERT(0, "CONFIG_SPL_BSS_MAX_SIZE and CONFIG_SPL_MAX_FOOTPRINT must not be defined together");
>> +#endif
>
> ... means CONFIG_SPL_BSS_MAX_FOOTPRINT can never be defined.
>
Correct. According to the README:

"CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
must not be both defined at the same time."

So this assert checks this. If this is wrong, then we should fix the
README instead.


>
> As a result,
>
>> +#if defined(CONFIG_SPL_BSS_MAX_SIZE)
>> +ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
>> +       "SPL image BSS too big");
>> +#endif
>
> the ifdef is always true, so meaningless.
Correct, we can remove this #ifdef

>
>> +ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS_MAX_SIZE), \
>> +       "SPL image BSS too big");
>
> is already size-checked by the following:
>
> MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR,
>          LENGTH = CONFIG_SPL_BSS_MAX_SIZE }
>
>
> so, meaningless.
>
>
>> +#if defined(CONFIG_SPL_MAX_FOOTPRINT)
>> +ASSERT(__bss_end - _start < (CONFIG_SPL_MAX_FOOTPRINT), \
>> +       "SPL image plus BSS too big");
>> +#endif
>
> This code is never enabled.
>
Correct, assuming we leave the above "#if
defined(CONFIG_SPL_BSS_MAX_SIZE) && defined(CONFIG_SPL_MAX_FOOTPRINT)"
in place.

Thanks,
Oded

>
>
> --
> Best Regards
> Masahiro Yamada

[U-Boot] [PATCH 1/2] armv8: calculate __bss_size in u-boot-spl.lds

[Oded Gabbay]

Hi Mashiro,
Could you please also take a look at the patch I sent to add the
missing __bss_size ?

Thanks,
Oded

On Mon, Dec 26, 2016 at 4:20 PM, Oded Gabbay <oded.gabbay@gmail.com> wrote:
> This patch adds a missing __bss_size symbol to the default armv8
> u-boot-spl.lds file.
> Makefile.spl relies on __bss_size to be present when it creates the SPL
> image. It uses that symbol to create a pad file that will be used to place
> the dtb after the bss section.
> In ARMv8 default u-boot-spl.lds, __bss_size was missing and therefore, the
> pad file was always 0. As a result, the dtb was placed after
> _image_binary_end, which caused a failure when loading it inside the SPL.
>
> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> ---
>  arch/arm/cpu/armv8/u-boot-spl.lds | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
> index cc427c3..e7799cc 100644
> --- a/arch/arm/cpu/armv8/u-boot-spl.lds
> +++ b/arch/arm/cpu/armv8/u-boot-spl.lds
> @@ -70,6 +70,7 @@ SECTIONS
>                 KEEP(*(.__bss_end));
>         } >.sdram
>
> +       __bss_size = __bss_end - _image_binary_end;
>         /DISCARD/ : { *(.dynsym) }
>         /DISCARD/ : { *(.dynstr*) }
>         /DISCARD/ : { *(.dynamic*) }
> --
> 2.7.4
>

[U-Boot] [PATCH 1/2] armv8: calculate __bss_size in u-boot-spl.lds

[Masahiro Yamada]

Hi.

(CCing Simon because he wrote the code addressed in this discussion.)


2017-01-17 18:27 GMT+09:00 Oded Gabbay <oded.gabbay@gmail.com>:
> Hi Mashiro,
> Could you please also take a look at the patch I sent to add the
> missing __bss_size ?
>
> Thanks,
> Oded
>
> On Mon, Dec 26, 2016 at 4:20 PM, Oded Gabbay <oded.gabbay@gmail.com> wrote:
>> This patch adds a missing __bss_size symbol to the default armv8
>> u-boot-spl.lds file.
>> Makefile.spl relies on __bss_size to be present when it creates the SPL
>> image. It uses that symbol to create a pad file that will be used to place
>> the dtb after the bss section.
>> In ARMv8 default u-boot-spl.lds, __bss_size was missing and therefore, the
>> pad file was always 0. As a result, the dtb was placed after
>> _image_binary_end, which caused a failure when loading it inside the SPL.
>>
>> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
>> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
>> ---
>>  arch/arm/cpu/armv8/u-boot-spl.lds | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
>> index cc427c3..e7799cc 100644
>> --- a/arch/arm/cpu/armv8/u-boot-spl.lds
>> +++ b/arch/arm/cpu/armv8/u-boot-spl.lds
>> @@ -70,6 +70,7 @@ SECTIONS
>>                 KEEP(*(.__bss_end));
>>         } >.sdram
>>
>> +       __bss_size = __bss_end - _image_binary_end;
>>         /DISCARD/ : { *(.dynsym) }
>>         /DISCARD/ : { *(.dynstr*) }
>>         /DISCARD/ : { *(.dynamic*) }



This patch seems wrong.


This linker script seems to support separate two memory regions.

MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE,
          LENGTH = CONFIG_SPL_MAX_SIZE }
MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR,
          LENGTH = CONFIG_SPL_BSS_MAX_SIZE }


_image_binary_end is the end of the first region (.sram),
__bss_end is the end of the second region (.sdram).

So, with your patch,

   __bss_size = (gap between .sram and .sdram) + (size of .bss)

This will append really big padding there is a gap between the two regions.
(at least, it will break my boards.)


If you take a look at fdtdec_setup(),

    #  ifdef CONFIG_SPL_BUILD
    /* FDT is at end of BSS unless it is in a different memory region */
    if (IS_ENABLED(CONFIG_SPL_SEPARATE_BSS))
             gd->fdt_blob = (ulong *)&_image_binary_end;
    else
             gd->fdt_blob = (ulong *)&__bss_end;

I think you are supposed to enable CONFIG_SPL_SEPARATE_BSS
if you want to use SPL_OF_CONTROL on your arm64 boards.



Checking the following commit will help you.


commit 10172962479ddd6609101fdb83bde66c0719852c
Author: Simon Glass <sjg@chromium.org>
Date:   Sat Oct 17 19:41:19 2015 -0600

    dm: spl: Support device tree when BSS is in a different section

    At present in SPL we place the device tree immediately after BSS. This
    avoids needing to copy it out of the way before BSS can be used. However on
    some boards BSS is not placed with the image - e.g. it can be in RAM if
    available.

    Add an option to tell U-Boot that the device tree should be placed at the
    end of the image binary (_image_binary_end) instead of at the end of BSS.

    Note: A common reason to place BSS in RAM is to support the FAT filesystem.
    We should update the code so that it does not use so much BSS.

    Signed-off-by: Simon Glass <sjg@chromium.org>
    Signed-off-by: Michal Simek <michal.simek@xilinx.com>


-- 
Best Regards
Masahiro Yamada

[U-Boot] [PATCH 1/2] armv8: calculate __bss_size in u-boot-spl.lds

[Simon Glass]

Hi,

On 19 January 2017 at 04:28, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> Hi.
>
> (CCing Simon because he wrote the code addressed in this discussion.)
>
>
> 2017-01-17 18:27 GMT+09:00 Oded Gabbay <oded.gabbay@gmail.com>:
>> Hi Mashiro,
>> Could you please also take a look at the patch I sent to add the
>> missing __bss_size ?
>>
>> Thanks,
>> Oded
>>
>> On Mon, Dec 26, 2016 at 4:20 PM, Oded Gabbay <oded.gabbay@gmail.com> wrote:
>>> This patch adds a missing __bss_size symbol to the default armv8
>>> u-boot-spl.lds file.
>>> Makefile.spl relies on __bss_size to be present when it creates the SPL
>>> image. It uses that symbol to create a pad file that will be used to place
>>> the dtb after the bss section.
>>> In ARMv8 default u-boot-spl.lds, __bss_size was missing and therefore, the
>>> pad file was always 0. As a result, the dtb was placed after
>>> _image_binary_end, which caused a failure when loading it inside the SPL.
>>>
>>> Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
>>> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
>>> ---
>>>  arch/arm/cpu/armv8/u-boot-spl.lds | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/arch/arm/cpu/armv8/u-boot-spl.lds b/arch/arm/cpu/armv8/u-boot-spl.lds
>>> index cc427c3..e7799cc 100644
>>> --- a/arch/arm/cpu/armv8/u-boot-spl.lds
>>> +++ b/arch/arm/cpu/armv8/u-boot-spl.lds
>>> @@ -70,6 +70,7 @@ SECTIONS
>>>                 KEEP(*(.__bss_end));
>>>         } >.sdram
>>>
>>> +       __bss_size = __bss_end - _image_binary_end;
>>>         /DISCARD/ : { *(.dynsym) }
>>>         /DISCARD/ : { *(.dynstr*) }
>>>         /DISCARD/ : { *(.dynamic*) }
>
>
>
> This patch seems wrong.
>
>
> This linker script seems to support separate two memory regions.
>
> MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE,
>           LENGTH = CONFIG_SPL_MAX_SIZE }
> MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR,
>           LENGTH = CONFIG_SPL_BSS_MAX_SIZE }
>
>
> _image_binary_end is the end of the first region (.sram),
> __bss_end is the end of the second region (.sdram).
>
> So, with your patch,
>
>    __bss_size = (gap between .sram and .sdram) + (size of .bss)
>
> This will append really big padding there is a gap between the two regions.
> (at least, it will break my boards.)
>
>
> If you take a look at fdtdec_setup(),
>
>     #  ifdef CONFIG_SPL_BUILD
>     /* FDT is at end of BSS unless it is in a different memory region */
>     if (IS_ENABLED(CONFIG_SPL_SEPARATE_BSS))
>              gd->fdt_blob = (ulong *)&_image_binary_end;
>     else
>              gd->fdt_blob = (ulong *)&__bss_end;
>
> I think you are supposed to enable CONFIG_SPL_SEPARATE_BSS
> if you want to use SPL_OF_CONTROL on your arm64 boards.
>
>
>
> Checking the following commit will help you.
>
>
> commit 10172962479ddd6609101fdb83bde66c0719852c
> Author: Simon Glass <sjg@chromium.org>
> Date:   Sat Oct 17 19:41:19 2015 -0600
>
>     dm: spl: Support device tree when BSS is in a different section
>
>     At present in SPL we place the device tree immediately after BSS. This
>     avoids needing to copy it out of the way before BSS can be used. However on
>     some boards BSS is not placed with the image - e.g. it can be in RAM if
>     available.
>
>     Add an option to tell U-Boot that the device tree should be placed at the
>     end of the image binary (_image_binary_end) instead of at the end of BSS.
>
>     Note: A common reason to place BSS in RAM is to support the FAT filesystem.
>     We should update the code so that it does not use so much BSS.
>
>     Signed-off-by: Simon Glass <sjg@chromium.org>
>     Signed-off-by: Michal Simek <michal.simek@xilinx.com>

Yes that's right. Thank you Masahiro.

Also, consider moving to use binman to generate the image.

Regards,
Simon