RE: [U-Boot-Users] Regarding memory commands
Hi,
Thanks!
As you said memory commands work in any memory region, is it only the internal flash memory or also external flash memory? By external memory I mean to say that the NOR or NAND memory is not in the processor chip (ARM). But NOR/NAND memories have separate chip and memory is mapped on to the ARM memory map.
I suppose NAND memory has different command set like nand info, etc. Then are these (mm, mw, md, etc) commands applicable for NAND memory also?
With regards and thanks
Aniruddha Herekar
-----Original Message----- From: S. Egbert [mailto:s.egbert@sbcglobal.net] Sent: Thursday, February 09, 2006 11:19 AM To: Herekar, Aniruddha Cc: u-boot-users@lists.sourceforge.net Subject: Re: [U-Boot-Users] Regarding memory commands
Herekar, Aniruddha wrote:
Does memory commands mm, mw, mn and tftp work only with RAM memory and
not flash (nor or nand) memory?
If so are there any other commands other than 'cp' that can be used to
write into flash (nor or nand) memory?
Basic memory commands (mm. mw) work in any memory region that the
hardware supports.
You will have to be mindful of certain memory and interface devices
using only 16-bit or 8-bit access in a 32-bit architecture. Otherwise,
such attempts to use 32-bit read/write will result in the most
significant short-word or byte NOT to carry valid data value.
TFTP does work writing directly into unprotected FLASH region if the
CFG_DIRECT_FLASH_TFTP is defined in your include/configs/<board>.h file.
Because it is essentially a file-store system and is not easily memory mappable in a direct sense of a word, the current memory command sets would not be easily extensible to cover this.
Closer examination of the U-boot cmd_nand.c shows that this is already done (Thanks Wolfgang and gang!)
A snippet of the NAND usage is given below:
"nand - NAND sub-system\n", "info - show available NAND devices\n" "nand device [dev] - show or set current device\n" "nand read[.jffs2[s]] addr off size\n" "nand write[.jffs2] addr off size - read/write `size' bytes starting\n" " at offset `off' to/from memory address `addr'\n" "nand erase [clean] [off size] - erase `size' bytes from\n" " offset `off' (entire device if not specified)\n" "nand bad - show bad blocks\n" "nand read.oob addr off size - read out-of-band data\n" "nand write.oob addr off size - read out-of-band data\n"
S. Egbert
Herekar, Aniruddha wrote:
As you said memory commands work in any memory region, is it only the internal flash memory or also external flash memory? By external memory I mean to say that the NOR or NAND memory is not in the processor chip (ARM). But NOR/NAND memories have separate chip and memory is mapped on to the ARM memory map.
I suppose NAND memory has different command set like nand info, etc. Then are these (mm, mw, md, etc) commands applicable for NAND memory also?
Herekar, Aniruddha wrote:
Does memory commands mm, mw, mn and tftp work only with RAM memory and not flash (nor or nand) memory? If so are there any other commands other than 'cp' that can be used to write into flash (nor or nand) memory?
Basic memory commands (mm. mw) work in any memory region that the hardware supports.
You will have to be mindful of certain memory and interface devices using only 16-bit or 8-bit access in a 32-bit architecture. Otherwise, such attempts to use 32-bit read/write will result in the most significant short-word or byte NOT to carry valid data value.
TFTP does work writing directly into unprotected FLASH region if the
CFG_DIRECT_FLASH_TFTP is defined in your include/configs/<board>.h file.
participants (2)
-
Herekar, Aniruddha -
S. Egbert