Re: Reverse engineering AT91RM9200 board

["Matt Wood" <mattwood2000@xxxxxxx>]

This page might help...its for a SAM9263, but the patches might be able to be ported:
http://ar.linux.it/pub/patches/at91sam9263ek-nor/README-html.html

Just browse up one directory from the README-html.htm to get the patch sourc.

Regards, Matt.

-------- Original-Nachricht --------
> Datum: Tue, 16 Dec 2008 00:09:26 +0100
> Von: viper@xxxxxxxxxxx
> An: Aras Vaichas <arasv@xxxxxxxxxxxxxx>
> CC: linux-arm@xxxxxxxxxxxxxxxxxxxxxx
> Betreff: Re: Reverse engineering AT91RM9200 board

> 
> 
> On Tue, 16 Dec 2008 09:42:19 +1100, Aras Vaichas <arasv@xxxxxxxxxxxxxx>
> wrote:
> > viper@xxxxxxxxxxx wrote:
> >> - U-boot is now 1.1.1 and want to change it. How can this be done?
> > Download the latest U-Boot and see if there is already support for your
> > board, otherwise you can ask the manufacturer for the board specific
> > patches. Otherwise, you will have to make your own board support. Try
> > the U-Boot mailing list for further information.
> 
> I don't know anything about the board an no one will tell me anything
> about
> it :( What I See Is What I Get :)
> 
> > 
> >> And how is U-boot loaded?
> >>
> > Do you mean "how is it burned into the Flash", or "where does it boot
> > from"?
> > 
> > U-Boot can boot from NOR flash (execute in place), or the first stage
> > bootloader can copy it from NAND/Dataflash into SDRAM and then execute
> it.
> > 
> > U-Boot can be programmed into your device via the first stage
> > bootloader, or via JTAG into the NOR/Dataflash.
> > 
> >> There's no DataFlash on the board, and as I can see
> >> everything is loaded from the NAND.
> >>
> > Look harder.  The at91rm9200 cannot boot from NAND, so there has to be
> > another memory device.
> > 
> > Is the memory OneNAND? What does dmesg say about the memory devices on
> > the board?
> 
> Just one  MX29LV320CTTC-70G flash, which is NOR, as I looked up. Problemo
> uno solved :)
> 
> > 
> >> Is it possible, that there's no
> >> "first-stage" boot loader like Darell loader, or Atmel's own?
> >>
> > AFAIK, this is only the case where you have NOR flash.
> 
> So, if it's a NOR flash, than no first-stage bootloader? Changing U-boot
> than is "just" writing it from the booted sys (get image via nfs)?
> 
> The partitions (from dmesg):
> 
> Flash device: 0x400000 at 0x10000000
> Physically mapped flash: mtfs filesystem found at block 1118
> Creating 6 MTD partitions on "Physically mapped flash":
> 0x00000000-0x00020000 : "bootcode"
> 0x00020000-0x003b0000 : "linux"
> 0x00117b84-0x003b0000 : "rootfs"
> 0x003b0000-0x003d0000 : "nvram"
> 
> > 
> > 
> >> - Kernel is 2.4.27 now. Tried to boot up a 2.6.26.8 via NFS, but got
> > "Bad
> >> magic number". What's that? ( compiled a kernel for AT91RM9200BGA with
> >> nearly default config )
> >>
> 
> Maybe it's u-boot, sincs my mkimage is for 1.1.4...
> 
> > It wasn't a U-Boot image, or the image was corrupt. This is how I make
> > my image:
> > 
> >         make ARCH=arm CROSS_COMPILE=${CROSS_PATH}
> > INSTALL_MOD_PATH=${FS_PATH} Image
> >         ${CROSS_PATH}/objcopy -O binary -S vmlinux linux.bin
> > 
> >         # zip up the file
> >         rm linux.bin.gz
> >         gzip -v9 linux.bin
> > 
> >         # create the U-Boot image
> >         ${MKIMAGE} -A arm -O linux -C gzip -a 0x20008000 -e 0x20008000
> > -d linux.bin.gz uImage
> > 
> >> - How can I make a correct board file for the board?
> > U-Boot or Linux?
> > 
> > Copy one of the other at91rm9200 board files and customize it for your
> > board.
> > 
> >> How can I get the NAND
> >> partitions, etc? ( most options I can configure )
> >>
> > What do you mean "get"?
> > 
> > dmesg should show you how any partitions are configured.
> > 
> > Try:
> > # cat /proc/partitions
> > # cat /proc/mtd
> > 
> > and see what it says.
> > 
> > To set NAND up in your board file, have a look at:
> > arch/arm/mach-at91/board-dk.c
> > 
> > static struct mtd_partition __initdata dk_nand_partition[] = {
> >     {
> >         .name   = "NAND Partition 1",
> >         .offset = 0,
> >         .size   = MTDPART_SIZ_FULL,
> >     },
> > };
> > 
> > static struct mtd_partition * __init nand_partitions(int size, int
> > *num_partitions)
> > {
> >     *num_partitions = ARRAY_SIZE(dk_nand_partition);
> >     return dk_nand_partition;
> > }
> > 
> > static struct at91_nand_data __initdata dk_nand_data = {
> >     .ale        = 22,
> >     .cle        = 21,
> >     .det_pin    = AT91_PIN_PB1,
> >     .rdy_pin    = AT91_PIN_PC2,
> >     // .enable_pin  = ... not there
> >     .partition_info = nand_partitions,
> > };
> > 
> >> - What's the easiest way to get the GPIO pins visible on the board?
> >>
> > There is kernel support, but I'm not sure of the current status. There
> > are a few user space applications around:
> > 
> > http://wiki.emqbit.com/at91-gpio
> > 
> > I use the one of this page:
> > http://dwisasongko.890m.com/User%20Space%20-%20Kernel%20space/
> > 
> > Aras
> > 
> > 
> 
> Thanks, 
> 
>      Tom
> 
> 
> > 
> > 
> > ______________________________________________________________________
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> 
> 
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