RE: [U-Boot-Users] what is wrong when calloc return bogus?
This has come up a couple times recently. I'll agree that from a consistency standpoint it would be nice if this were same for all architectures, and it will probably end up this way, but is it really "broken", what is not currently functioning, other than a proper mapping from the documentation to reality.
Regards,
Richard W.
-----Original Message----- From: Wolfgang Denk [mailto:wd@denx.de] Sent: Friday, August 15, 2003 2:51 PM To: Woodruff, Richard Cc: 'Holger Schurig'; u-boot-users@lists.sourceforge.net Subject: Re: [U-Boot-Users] what is wrong when calloc return bogus?
In message
If the PXA is broken, then it should be fixed, but NOT by
making it like the other ARM boards which are (IMHO) broken by design. [It's just that we didn't have enough free resources (or volunteers???) to fix the ARM memory layout.]
ARM still suffers from the many things ARMBoot did differently.
Best regards,
Wolfgang Denk
-- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de "In Christianity neither morality nor religion come into contact with reality at any point." - Friedrich Nietzsche
In message FD2AC9A020DDD51194710008C7089B200BEE22B9@dlee17.itg.ti.com you wrote:
This has come up a couple times recently. I'll agree that from a consistency standpoint it would be nice if this were same for all architectures, and it will probably end up this way, but is it really "broken", what is not currently functioning, other than a proper mapping from the documentation to reality.
The design idea of U-Boot is that you boot from flash, initialize RAM, measure the size of available RAM, and then use RAm in a top down way. If we exclude more exotic features like pRAM, log buffer, or frame buffer memory that shall be reused by the Linux kernel this means copy U-Boot code, data and bss to the end of RAM, below it you place the malloc arena, and below that the stack (growing downward). This is easy to implement, and provides maximum flexibility even in cases where the memory size of a board is unknown at compile time.
Also, it allows the aforementioned "exotic" features like passing information from U-Boot (like POST results) in a syslog compatible way to Linux, or initializing a framebuffer in U-Boot (with a splash screen for example) and keep this image steady until the Linux application start, or pRAM, where data can be stored which will not be changed by a warmboot.
Best regards,
Wolfgang Denk
participants (2)
-
Wolfgang Denk -
Woodruff, Richard