Re: [linuxsh-dev] sh-ipl+g

[Jeremy S. <js...@mv...>]

Not sure I understand why there's an issue with 16-bit versus 32-bit; as
long as the endian is correct and the programming software puts the bytes in
the right place (start from 0 and work your way up) why shouldn't it work?

Building the stub in RAM has several issues: (1) whatever your real boot-rom
is has to initalize the BSC; (2) the stub must NOT re-initialize the BSC;
(3) you've got to pick a place in RAM such that anything else you're using
will avoid stomping on it.  I tried doing this some time ago (I forget
exactly why); the attached patch might be helpful in that regard.

It will build an sh-ramstub.srec which keeps the BSS/Data where the normal
stub does, but moves the text to 0x8D000000, leaving 16M for the kernel
(you'd have to force your kernel to limit itself so as not to overwite the
stub, or configure it to not use the stub and let it overwrite after the
kernel is loaded.  I have not tried this.)  If you want to use sh-ethboot,
of course, you'd need to make similar changes in that (drop -DROM from
CFLAGS in the Makefile, adjust the start address in standalone-ram.lds) and
use a config.h that defines CONFIG_BOOT_LOADER1 to whatever you set the
sh-ethboot start address to.  (And then you've got three pieces of code --
the stub, the loader, and the kernel -- to prevent overlap between.)

--Jeremy Siegel



akira wrote:

> No, i don't use the  ipl+g in Area0 because i can't use the flash rom.
> The board is little-endian and the rom is 16 bit. (flash rom is 32 bit).
> I think that the gcc is right.
>
> Se sei italiano, o se parli italiano scrivimi pure. ho un po' di problemi
> con l'inglese.
>
> ----- Original Message -----
> From: "Fabio Giovagnini" <fg...@ti...>
> To: "akira" <aki...@ho...>; <lin...@li...>
> Sent: Tuesday, March 19, 2002 6:47 PM
> Subject: Re: [linuxsh-dev] sh-ipl+g
>
> > Were you able to use sh-ipl+g in Area0 ?
> > Is your board little-endian or big-endian?
> > How are you sure to compile good for your target?
> > Is your boot rom 8 or 16 bit?
> >
> > Thanks
> >
> > On Tuesday 19 March 2002 18:41, akira wrote:
> > > I have a 7727 (SH3-DSP) based board (PFM-DS11), this board uses the
> > > standard Hitachi layout. IT is possible to use ipl+g in Area3
> (H'0c000000)?
> > > and how could i do?
> > >
> > > thanks!
> >
>
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