Thanks Brett,
I am using gpio for Sdcard detect, CS. For tx, rx, clk i am using SPI port
signals. At this stage I have got the initial 2k bootloader working from serial
EEPROM/Flash. The current setup uses redboot => linux kernel => Application.
As you have suggested to boot from sdcard it can be 2 options
1) 2K bootloader (eeprom) => second stage bootloader to initialize sdcard =>
redboot (sdcrd)=> linux (sdcrd) => Appn (sdcrd).
2) 2K bootloader + redboot(eeprom) => linux (sdcrd) => Appn (sdcrd).
Is it necessary to have redboot for loading linux kernel. Can we load the
kernel directly from second stage bootloader without using redboot.
Can you please provide some pointers on this.
Cheers
Tama
--- In "Breton M. Saunders" <>
wrote:
>
> I wrote the original linux loader for the alertme hub - fit the entire
> NAND flash loader into about 1.2k of eeprom space, including CRC codes.
> The development board for it was a ts7400.
>
> When I was looking at the sdcard last year I figured that it would be
> quite difficult to fit the boot loader into the 2k eeprom on the
> ts7400. With about 5k I think its possible; but you'll need at least 3
> stages of loader.
>
> Incidentally, since you have done your own board, how have you connected
> the sdcard to the ep9307 - are you gpio banging it?
>
> The TS boards have a pretty simple 4 bit interface onto the sdcard that
> is implemented in the CPLD.
>
> If I remember correctly, they do something like a 3 stage loader on the
> ts7400:
> Stage 1: 2k loaded from eeprom into cirrus's ethernet buffer to start
> the system and load the 1st page (which are supposed to be reliable)
> from NAND and call it.
> Stage 2: Load the first 16k from NAND using CRC and call it.
> Stage 3: Load Linux from NAND or load Linux from partition 0 of the
> sdcard (tsfastboot vs tssdboot).
>
> Loading linux itself is quite easy - just copy the data into ram, setup
> the registers correctly and jump to the start address.
>
> Oh yeah - since you've done your own board, have you correctly managed
> the ep93xx lockup-on-reset bug? About 1/3 of the chips have this
> problem. TS works around it using their CPLD and watchdog.
>
> -Brett
>
>
> pkm_munot wrote:
> > --- In Jason Stahls <jason@> wrote:
> >
> >> pkm_munot wrote:
> >>
> >>> Hi Guys,
> >>>
> >>> As per the manual under boot section. This board as a initial bootloader
> >>> in EEPROM which is loaded at power up and later talks to SDcard. Apter
> >>> initializing of SDcard the boards boots from SDcard directly. I am trying
> >>> to implement a similar boot sequence for my board based on EP9307 chip.
> >>>
> >>> Can anyone please provide some pointers to the source code for EEPROM
> >>> bootloader and TS_SDBOOT.
> >>>
> >> I doubt TS will release the code for their bootloader but the best way
> >> to get it would call them and ask for it. Now for SD boot, I believe
> >> the SD interface is implemented in the FPGA so that would hose using
> >> TS's boot loader anyways :(
> >>
> >> --
> >> Jason Stahls
> >>
> >>
> >
> > Thanks Jason,
> >
> > I will trying calling them and see if I can get any pointers from them. As
> > per the current design for TS7300 I guess the sdcard interface is
> > implemented in FPGA. In my case I dont have a FPGA but I have a serial
> > flash. I have downloaded spi_boot example from Cirrus logic website and its
> > working successfully on my board.
> >
> > Now I am trying to write a second stage bootloader which will initialize
> > the sdcard and load redboot from sdcard. This in turn will load rest of the
> > bits from SDcard.
> >
> > Its this approach right?
> > Cheers
> > Tama
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>
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