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Re: Booting from Flash in a AT91M55800A based platform
- From: Marc-Andrà Beck <marc-andre_beck at gmx dot ch>
- To: Frank Pagliughi <fpagliughi at mindspring dot com>, Lambrecht J Ãrgen <J dot Lambrecht at TELEVIC dot com>
- Cc: eCos Discuss <ecos-discuss at ecos dot sourceware dot org>
- Date: Mon, 25 Aug 2008 14:46:44 +0200
- Subject: [ECOS] Re: Booting from Flash in a AT91M55800A based platform
- References: <48B290B3.6080804@netlabs.org>
Hi,
I'm a coworker of Nuria and am rather new to this project. So i reply to
this mail.
Lambrecht JÃrgen wrote:
Frank Pagliughi wrote:
> Pazos Escudero Nuria wrote:
>
> >Hi,
> >
> >I've ported eCos and RedBoot for a proprietary platform comprising the
> >AT91M55800A processor a SRAM and three S29AL016D90TFI02 flash modules.
> >The RAM version works fine and I can communicate with the RedBoot
> >console through the serial port, but I have not yet managed to make
Can you access the flash from redboot? (fis init; fconfig -I; ..)
No. while booting from RAM I only see the RAM. There's no FLASH part:
RAM: 0x40000000-0x40080000, [0x4001f1e8-0x40034000] available
Trying to build the "Flash Tools" (CYGSEM_REDBOOT_FLASH_CONFIG) fails
with a linking error:
.../libtarget.a(redboot_fconfig.o): In function `do_flash_config':
.../fconfig.c:322: undefined reference to `__flash_init'
As the flash (NAND) supports the JEDEC-standard, shouldn't it be
accessible from RedBoot with a generic driver?
Are the flash things OK? You can use the arm/at91/eb55 port as starting
point. You need also flash code in devs/flash/arm/eb55 and
devs/flash/amd/am29xxxxx -> I just checked
devs/flash/amd/am29xxxxx/current/include/flash_am29xxxxx_parts.inl, and
there is no S29AL part in the list.
Just add it. You can start from the CYGHWR_DEVS_FLASH_AMD_S29GL128N
part, and check your datasheet for changes.
(mark: the eb55 board uses an atmel flash of course, so the part used ('
#define CYGHWR_DEVS_FLASH_ATMEL_AT49BV1604A ') is in
devs\flash\atmel\at49xxxx\current\include\ flash_at49xxxx_parts.inl)
You could also have problems because of the 3 flash chips. Start with
using only 1.
If you want to use the 3 flashes separately, I think you need then the
flash_v2 drivers - check the mailing list for it.
> the
> >platform boot from the flash (after copying the ROM version of the
> >ported RedBoot on the flash address pointed by the chip select 0). I
> >don't know whether the problem comes from the platform porting or from
> >the fact that eCos does not recognize the used flash chips from
> >Spansion. Could you provide me any hint?
> >
> >Thanks in advance!
> >Nuria
> >
> >
> >
> If you're programming the Flash chips with a JTAG, then the lack of
> eCos
> drivers doesn't matter at this stage.
Yes, it was done using a JTAG.
> - Does the JTAG software claim that the "program and verify" worked
> properly?
Yes.
> - Are the Flash chips properly wired on the board?
Yes. Verified and reverified.
> - Did you set up the "_InitMemory" table in "hal_platform_setup.h" for
> the Flash chip(s). You need to set the base address, # wait states,
> etc.
I adapted them for the S29AL016D90TFI02:
.long 0x100037B1 // NAND Flash, 2MB, 3 cycles after transfer,
16-bit, 5 wait state
.long 0x200037B1
.long 0x300037B1
.long 0x40002121 // RAM
...
Still the Spansion S29AL016D is NAND-Flash with a bottom boot block. So
i am booting from NAND. Is this a problem as the ATMEL AT91M55800A
should be capable of code shadowing?
Regarding the boot block of the NAND: Shouldn't it be XIP (execution in
place) capable?
> Plus the base address for each CS line must be different, even if the
> CS
> is disabled.
Indeed.
I have a 64MB S29GL512, and use 4 chip-selects for it.
Here is my "_InitMemory" code:
.long 0x1000352D //NCS0 flash-1 , 16MB, 2 cycles after
transfer, 16-bit, 4 wait state
.long 0x1100352D //NCS1 flash-2 , 16MB, 2 cycles after
transfer, 16-bit, 4 wait state
.long 0x1200352D //NCS2 flash-3 , 16MB, 2 cycles after
transfer, 16-bit, 4 wait state
.long 0x1300352D //NCS3 flash-4 , 16MB, 2 cycles after
transfer, 16-bit, 4 wait state
.long 0x06002121 //NCS4 IDT SRAM, 16MB, 0 cycles after
transfer, 16-bit, 1 wait state
Starting from the eb55 port, I first used addresses 0x0100, 0x0200,
0x0300 and 0x0400. But this did not work very well! I still don't know
why. The addresses 0x1000, 0x1100, .. worked, so I stopped my effort there.
> - You should be able to reset the CPU and single step through the first
> few instructions, using the JTAG and/or gdb. Remember that the chip
> starts with the first Flash (CS0) mapped to address zero. You can
> single
> step up to the point where the chip select registers are loaded and
> make
> sure that the values are being loaded properly. But note that you
> can't
> step over the remap command since the debugger messes with the
> pipeline.
> - One of the first things that the assembly startup does is set the
> master clock (and maybe the PLL) running faster. If you set them
> running
> faster than the external board can support, the board may lock up.
>
>
> Whatever you're using to load the RAM debug code onto the board is
> initializing it properly (a JTAG initialization file?). Use that as a
> starting point. The only thing it isn't doing is setting up the Flash
> chip select registers in the EBI, so pay careful attention to that.
>
> Frank
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