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From: Timur Tabi <timur@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] CFG_MONITOR_BASE < CFG_FLASH_BASE
Date: Wed, 16 May 2007 15:47:08 -0500	[thread overview]
Message-ID: <464B6DCC.4030203@freescale.com> (raw)

In several board config files (namely 8xxx boards), I see code that looks like this:

#if (CFG_MONITOR_BASE < CFG_FLASH_BASE)
#define CFG_RAMBOOT
#else
#undef  CFG_RAMBOOT
#endif

...

#ifndef CFG_RAMBOOT
   #define CFG_ENV_IS_IN_FLASH	1
   #define CFG_ENV_ADDR		(CFG_MONITOR_BASE + CFG_MONITOR_LEN)
   #define CFG_ENV_SECT_SIZE	0x40000	/* 256K(one sector) for env */
   #define CFG_ENV_SIZE		0x2000
#else
   #define CFG_NO_FLASH		1	/* Flash is not usable now */
   #define CFG_ENV_IS_NOWHERE	1	/* Store ENV in memory only */
   #define CFG_ENV_ADDR		(CFG_MONITOR_BASE - 0x1000)
   #define CFG_ENV_SIZE		0x2000
#endif

So CFG_RAMBOOT is defined if U-Boot is located in RAM instead of in Flash.

On a system that has flash, why would we ever support this configuration?  It doesn't even 
make any sense, because a whole bunch of DDR and LAWBAR setup needs to happen before RAM 
can even be accessed, so you can't copy u-boot to RAM and reset the system.

-- 
Timur Tabi
Linux Kernel Developer @ Freescale

             reply	other threads:[~2007-05-16 20:47 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-16 20:47 Timur Tabi [this message]
2007-05-16 22:04 ` [U-Boot-Users] CFG_MONITOR_BASE < CFG_FLASH_BASE Wolfgang Denk
2007-05-16 22:11   ` Timur Tabi
2007-05-16 23:04     ` Leonid
2007-05-16 23:11       ` Timur Tabi
2007-05-17  2:12         ` Leonid
2007-05-17 15:35         ` Jon Loeliger
2007-05-17  0:11       ` Wolfgang Denk
2007-05-17  1:47         ` Leonid
2007-05-17 10:00           ` Wolfgang Denk
2007-05-16 23:34     ` David Hawkins
2007-05-17 14:55       ` Timur Tabi
2007-05-17 15:55         ` David Hawkins
2007-05-17 20:29         ` Wolfgang Denk
2007-08-16 11:31       ` Florian Boelstler
2007-08-16 11:51         ` Wolfgang Denk
2007-05-17  0:08     ` Wolfgang Denk

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