[U-Boot] [U-Boot, v3, 3/9] fat/fs: convert to directory iterators

[Adam Ford]

On Sun, Sep 17, 2017 at 7:53 AM, Rob Clark <robdclark at gmail.com> wrote:
> On Sun, Sep 17, 2017 at 7:08 AM, Adam Ford <aford173 at gmail.com> wrote:
>>
>> Adding the debug to master made no difference.  No debug messages appeared.
>> Interestingly enough, some junk appeard, and the name of U-Boot name
>> wasn't correctly displayed:
>>
>> **Sș017.09-00178-g08cebee-dirty (Sep 17 2017 - 06:01:07)
>> Trying to boot from MMC1
>>
>> (hang)
>>
>

With the TINY_PRINTF disabled (except in SPL),  the log looks better:

Trying to boot from MMC1
reading u-boot.img
VFAT Support enabled
FAT16, fat_sect: 1, fatlength: 200
Rootdir begins at cluster: 536870910, sector: 401, offset: 32200
Data begins at: 417
Sector size: 512, cluster size: 8
FAT read(sect=401, cnt:2), clust_size=8, DIRENTSPERBLOCK=16
RootMismatch: |mlo||
Rootvfatname: |u-boot.img|
RootName: u-boot.img, start: 0x12, size:  0x83708
Filesize: 538376 bytes
64 bytes
gc - clustnum: 18, startsect: 561
Size: 538376, got: 64
reading u-boot.img
VFAT Support enabled
FAT16, fat_sect: 1, fatlength: 200
Rootdir begins at cluster: 536870910, sector: 401, offset: 32200
Data begins at: 417
Sector size: 512, cluster size: 8
FAT read(sect=401, cnt:2), clust_size=8, DIRENTSPERBLOCK=16
RootMismatch: |mlo||
Rootvfatname: |u-boot.img|
RootName: u-boot.img, start: 0x12, size:  0x83708
Filesize: 538376 bytes



> hmm, one thing I noticed in doc/README.SPL:
>
> "When building SPL with DEBUG set you may also need to set CONFIG_PANIC_HANG
> as in most cases do_reset is not defined within SPL."
>
> not sure if that would help.
>

I did try your experiment with keeping the working SPL and using the
newer u-boot.img file and that worked, so I am guessing it's probably
related to tight memory in SPL.
I looked up the mapping in doc/SPL/README.omap3 and it shows:

0x40200800 - 0x4020BBFF: Area for SPL text, data and rodata
0x4020E000 - 0x4020FFFC: Area for the SPL stack.
0x80000000 - 0x8007FFFF: Area for the SPL BSS.
0x80100000: CONFIG_SYS_TEXT_BASE of U-Boot
0x80208000 - 0x80307FFF: malloc() pool available to SPL.

For this board, CONFIG_SYS_SPL_MALLOC_SIZE is set to 0x100000

I don't know if any of this is helpful information to you or not.

> Also, it has a section about estimating stack usage.. not sure if this
> implies that stack size is constrained in spl?  If so, maybe that is
> related.  The new directory iterators do move the buffer for current
> block of dir_entry's to the stack.  Reducing
> CONFIG_FS_FAT_MAX_CLUSTSIZE might help.

Any recommendations on how small this can go and still operate
reliably?  I don't want to just arbitrarily choose something.

>
> BR,
> -R

adam