[PATCH 8/8] mx25 3ds: add support for boot from UART

[Sascha Hauer]

On Thu, Jun 10, 2010 at 02:49:39PM +0300, Baruch Siach wrote:
> Hi Sascha,
> 
> On Thu, Jun 10, 2010 at 01:12:37PM +0200, Sascha Hauer wrote:
> > On Wed, Jun 09, 2010 at 10:05:07AM +0300, Baruch Siach wrote:
> 
> [snip]
> 
> > > --- a/board/freescale-mx25-3-stack/3stack.c
> > > +++ b/board/freescale-mx25-3-stack/3stack.c
> > > @@ -44,7 +44,11 @@ extern unsigned long _stext;
> > >  
> > >  void __naked __flash_header_start go(void)
> > >  {
> > > +#if defined CONFIG_FREESCALE_MX25_3STACK_UART_BOOT
> > > +	__asm__ (".word	exception_vectors\n");
> > > +#else
> > >  	__asm__ __volatile__("b exception_vectors\n");
> > > +#endif
> > 
> > Do we need this change? I booted other i.MX SoCs without it. I really
> > like to keep this because it enables to jump to the first address if
> > booting second stage.
> 
> This is actually a (very) short "flash" header with only the 
> app_code_jump_vector entry left. Only reverse engineering the Freescale ATK 
> software revealed this secret. Reading through the i.MX25 Reference Manual I 
> now see that there is an option to pass DCD separately, but it complicates the 
> boot sequence.  This change only affects builds when this configuration 
> option, and this option is disabled by default.

What do you use to upload images? I once updated my favourite terminal
program microcom (git://git.pengutronix.de/git/tools/microcom) to be
able to upload and start images. I didn't need any special images. I
just used the ability to write registers to initialize the SDRAM and
then uploaded an image to sdram with image type 0xaa which seems to
just start the image at the given address. Find a log attached (which is
on an i.MX27, but I tested it on i.MX35 and i.MX51 aswell)
Maybe this could be a solution for you aswell.

Anyway, that said, I can apply your patch, too. I just find it very
comfortable to use one image for all boot scenarios.

Sascha

sha at kiwi:~/octopus/microcom/microcom ./microcom -p /dev/ttyS0 -f
connected to /dev/ttyS0
Escape character: Ctrl-\
Type the escape character followed by c to get to the menu or q to quit

barebox:/
Enter command. Try 'help' for a list of builtin commands
-> x b
mw 0xD8001010 0x00000004
mw 0xD8001004 0x006ac73a
mw 0xD8001000 0x92100000
mw 0xA0000f00 0x12344321
mw 0xD8001000 0xa2100000
mw 0xA0000000 0x12344321
mw 0xA0000000 0x12344321
mw 0xD8001000 0xb2100000
mwb 0xA0000033 0xda
mwb 0xA1000000 0xff
mw 0xD8001000 0x82226080
mw 0xA0000000 0xDEADBEEF
mw 0xD8001010 0x0000000c
upload 0xa0000000 /home/sha/octopus/barebox/barebox/barebox-pcm038.bin 0xaa
image type: 0xaa

    ################################################################
    ################################################################
    ########################################

----------------------
����

barebox 2010.04.0-00140-g0a28ada-dirty (Apr 15 2010 - 11:40:21)

Board: Phytec phyCORE-i.MX27
cfi_probe: cfi_flash base: 0xc0000000 size: 0x02000000
NAND device: Manufacturer ID: 0x20, Chip ID: 0x36 (ST Micro NAND 64MiB
1,8V 8-bit)
Bad block table found at page 131040, version 0x01
Bad block table found at page 131008, version 0x01
imxfb at imxfb0: i.MX Framebuffer driver
ULPI Vendor ID 0xffffff92    Product ID 0xffffff92
No ISP1504 found
ehci at ehci0: USB EHCI 1.00
cfi_protect: protect 0xc0040000 (size 131072)

Using environment in NOR Flash
initialising PLLs: 0xa7f1ea18 0xa7f291f4
Malloc space: 0xa6f00000 -> 0xa7f00000 (size 16 MB)
Stack space : 0xa6ef8000 -> 0xa6f00000 (size 32 kB)
running /env/bin/init...

Hit any key to stop autoboot:  2

type update_kernel nand|nor [<imagename>] to update kernel into flash
type update_root nand|nor [<imagename>] to update rootfs into flash

barebox:/

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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> 
> baruch
> 
> -- 
>                                                      ~. .~   Tk Open Systems
> =}------------------------------------------------ooO--U--Ooo------------{=
>    - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |