Re: XIP - Execute in Place (For Bootloader)


karthikbg wrote:
Hi,
I was trying to bypass Boot ROM and Branch to Bootloader's entry point
by some form of RESET configurations in OMAP. I did not get any
specific RESET mode/configurations for this. Further,
I find that it is not possible to bypass Boot ROM as it plays a very
important role . I find that if i design by bypassing the boot ROM,
then the bootloader will not get copied to the RAM from the Flash. The
Boot ROM has the basic OMAP intialisaton stuffs and is copying the
Bootloader from the Flash to RAM , then it invokes the bootloader in
RAM.
The Bootloader is copying my application from Flash to RAM and invokes
the application in RAM.

So, I think, I cannot bypass Boot ROM . (That is , I cannot Branch to
Bootloader Entry point directly after RESET).

But, I think, the following is possible - Making the Bootlaoder to
execute in Flash itself:
---------------------------------------------------------------------------------------------------------------------------------
I would like to execute the Bootloader from the Flash Memory itself
(Execute in Place - XIP ).
The bootloader CMD files (Linker command Files) have the RAM memory
mapping as it was designed to execute in RAM. So, the CMD files of the
Bootloader has to be changed .

But, How to make the Bootloader to Execute from the Flash Memory itself
?

Kindly let me know your ideas / suggestions.

Thx in Advans,
Karthik Balaguru

I am avoiding the concept of Bootloader getting copied to the RAM for
execution and I have selected the concept of eXecute In Place (XIP)
cocept because I need the RAM for an another activity. But what are the
things that i need to consider to makethe bootloader to eXecute in
Flash Memory itself ?

How to Tell to my Processor that it has to execute the
contents(Bootloader) in Flash Memory itself ?

Does XIP use RAM for certain activities or ONLY THE FLASH MEMORY ?
Should I need to place some part of the bootloader sections (data) in
RAM ? -> I am worried about this because i will be having some data in
RAM.

Does XIP(eXecute in Place) reduce the lifetime of my Flash Memory ?

What are the possible sources of problem if i use the XIP(eXecute In
Place) concept ?

Could anyone of you here kindly share some doc/link regarding the XIP ?

Thx in advans,
Karthik Balaguru

.

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