From: Wolfgang Denk <wd@denx.de>
To: Steven Blakeslee <BlakesleeS@embeddedplanet.com>
Cc: "'linuxppc-embedded@lists.linuxppc.org'"
<linuxppc-embedded@lists.linuxppc.org>
Subject: Re: execute from flash?
Date: Mon, 25 Feb 2002 21:50:37 +0100 [thread overview]
Message-ID: <20020225205042.64FC9109E3@denx.denx.de> (raw)
In-Reply-To: Your message of "Mon, 25 Feb 2002 15:17:14 EST." <D73A25AA6E54D511AD74009027B1110F0F30B0@ORION>
Steven,
in message <D73A25AA6E54D511AD74009027B1110F0F30B0@ORION> you wrote:
>
> Does anyone know how I can run a program in flash from my embedded linux
> kernel that is also running in flash? Below is the code that I tried but it
I don't think your kernel is running from flash. It is stored in
flash, but usually then it gets loaded (and probably uncompressed)
into RAM, and is running from RAM.
YOu can do similar things whith your own code: you can put it in
flash, and load it from flash into RAM to run it. This requires that
you have some way to access the flash memory - under Unix this
requires either a basic device driver (character device), or a more
sophisticated device driver (block device) that allows you to put a
filesystem in flash.
> int addr = 0xfff80000;
You cannot access arbitrary physical addresses from an application
program. Linux uses virtual memory, and you should get used to the
idea that you cannot access physical memory or devices except through
some special interfaces provided by the OS (system calls which
usually require some device drivers).
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de
I must follow the people. Am I not their leader? - Benjamin Disraeli
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2002-02-25 20:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-25 20:17 execute from flash? Steven Blakeslee
2002-02-25 20:50 ` Wolfgang Denk [this message]
-- strict thread matches above, loose matches on Subject: below --
2002-02-25 22:23 Petersen, David (MED, GEMS-IT)
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