[U-Boot] Handling images(.jpg, .bmp etc) in u-boot

[Bhargav AK]

Anatolij,

Thanks for the direction you gave..

I'm able to move all the images into one partiton and display each of them
on need basis
by branching to the respective offset addresses.

I need to know the following, can you please give me your suggestion:

I have been asked to find out if u-boot supports displaying images without
having to store them into any
partition in advance. (Why ? the question here was, what if someone forgets
to flash the images ? bizzare ? I don't know.. ;) )

Can we zip a .bmp image and compile it with a u-boot and unzip the archive
runtime ?
If this is possible, can it be done without increasing the size of the
"u-boot.bin" ?

I tried the "xxd -i" command to get a hex dump of the .zip file into a ".h"
file,
but this method increased the size of the "*.h" file generated. (it is
almost the same as the .bmp file inside the .zip)

Can you please give me your suggestions.

Regards
Bhargav




On Sun, Mar 31, 2013 at 6:51 PM, Anatolij Gustschin <agust at denx.de> wrote:

> On Sun, 31 Mar 2013 04:54:35 -0700 (PDT)
> bhargavak <anur.bhargav at gmail.com> wrote:
>
> > That's a very nice explanation..
> > Here's what I will do, please tell me if the whole procedure is right.
> >
> > I have a SD-card partitioned as follows:
> > boot: FAT32, holds a MLO and u-boot.bin through which I boot my device
> (runs
> > on OMAP4470)
> > rootfs: mostly empty always (ext4 currently), I will format it as FAT32
> >
> > I copy "slide-0.bmp" into the rootfs partition and define
> > "CONFIG_SYS_HUSH_PARSER".
>
> Note that CONFIG_SYS_HUSH_PARSER is not necessary if you do not
> use 'for' or 'while' loops (but it won't hurt, an maybe it is
> already defined in your config file).
>
> > Then I stop the bootloader before the kernel starts, do "setenv" as
> follows,
> > and "saveenv"
> > > show_one=fatload mmc 0:2 40001000 slide-${i}.bmp;bmp d 40001000
>
> Note that when Wolfgang showed you this example, it was only
> for reference how it could be done. You shouldn't blindly input
> commands without understanding what these commands are supposed
> to do. You also should read the command documentation in the
> U-Boot manual and apply common sense. For example the load address
> 40001000 in the above example is valid only for a particular
> architecture, starting offset of the DRAM memory and available
> memory size. Using 40001000 address in your case might be wrong.
>
> In your case only 512 MiB DRAM is available, you need to figure
> out where the DRAM starts. Use "bdinfo" command and look at
> the  DRAM bank start value, i.e.:
>
> U-Boot > bdinfo
> ...
> DRAM bank   = 0x00000000
> -> start    = 0x10000000
> -> size     = 0x40000000
> ...
>
> In this example the memory starts at address 0x10000000, so a
> reasonable load address could be 10001000 (since the area
> starting from 10000000 might contain interrupt/exception vectors,
> we skip 0x1000 sized block at start of DRAM).
>
> for setting the environment variable use
>
>  setenv show_one 'fatload mmc 0:2 40001000 slide-0.bmp;bmp d 40001000'
>
> but replace 40001000 address with a valid address for your board.
> On my board from the above example I could use address 10001000.
>
>
> > Then do the following:
> > > run show_one
> >
> > I should be able to see the image on the screen ?
>
> Provided you used a valid load address and enabled support
> for "bmp" command and splash screen, yes.
>
> > Is there any other configuration options that I should enable ?
>
> I do not know your board and do not have your U-Boot source, so
> cannot tell for sure. But you need at least
>
> CONFIG_CMD_BMP
> CONFIG_SPLASH_SCREEN
> CONFIG_VIDEO
> CONFIG_CFB_CONSOLE
> CONFIG_VGA_AS_SINGLE_DEVICE
> CONFIG_SYS_CONSOLE_IS_IN_ENV
>
> and the config option to enable your video driver.
>
>
> > For some reason "saveenv" was not working for me yesterday, when I tried
> to
> > experiment with the "splashimage" environment variable.
> > I do not remember the exact error it threw, I could post the error first
> > thing tomorrow from my workplace.
> > As a workaround can I set above variables in my "OMAP" config header ?
>
> Look at the CONFIG_EXTRA_ENV_SETTINGS definition in your config
> header. It includes additional definitions for embedded environment.
> You could add your variables in this list, but it is only used
> if the default environment is used. Your board is not in mainline,
> so I cannot tell exactly what else might be needed.
>
> > My u-boot version is "U-Boot 1.1.4-geb3fa991".
>
> This version is _very_ old, we do not support it.
>
> Thanks,
>
> Anatolij
>