From: Jonathan Larmour <jlarmour@redhat.com>
To: Dave Airlie <airlied@parthus.com>
Cc: ecos-discuss@sources.redhat.com
Subject: Re: [ECOS] eCos PID ROM/RAM
Date: Mon, 29 Jan 2001 10:01:00 -0000 [thread overview]
Message-ID: <3A75AFF5.BD4B13A2@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.21.0101271243430.16685-100000@platinum.limerick.sslinc.com>
Dave Airlie wrote:
>
> I created a ROMRAM config for my PID which copies my ROM image down to RAM
> and jumps to it ... it does the copy in PLATFORM_SETUP1 Macro, after
> enabling the RAM, I've also used the PID RAM linker files for the ROMRAM
> setup and added defined(ROMRAM) where I thought was necessary, however
> I've hit a problem with the booting of the ROM, because I've used RAM
> linked scripts (which is correct because it is running out of RAM), the
> reset_vector is incorrect it is at 0x8044, so I am hexediting the produced
> image to make the reset_vector 0x04000044, where the ROM is,
>
> How to other platforms handle this problem? or do they do some MMU pokery
> to get around it?
Include the memory layout .h file (CYGHWR_MEMORY_LAYOUT_H), like the SH HAL
does, and then in vectors.S, change:
#ifdef CYGHWR_HAL_ARM_HAS_MMU
#define UNMAPPED(x) ((x)-__exception_handlers)
#else
#define UNMAPPED(x) (x)
#endif
to also provide for ifdef CYG_HAL_STARTUP_ROMRAM and doing, e.g.
#define UNMAPPED(x) (x-CYGMEM_REGION_ram+CYGMEM_REGION_rom)
> also I have a ldr pc,0x8074 in my code to jump to RAM,
> this is something I don't like anyone got a better way for me to jump to
> the RAM image once it is copied?
b __foo
__foo:
Since __foo will be the address in RAM.
Jifl
--
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine
prev parent reply other threads:[~2001-01-29 10:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-01-27 4:47 Dave Airlie
2001-01-29 10:01 ` Jonathan Larmour [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3A75AFF5.BD4B13A2@redhat.com \
--to=jlarmour@redhat.com \
--cc=airlied@parthus.com \
--cc=ecos-discuss@sources.redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).