how to change the MIPS bootloader start address

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how to change the MIPS bootloader start address

Postby canbumanikandan » Mon Apr 27, 2009 3:27 am

Hi,
I have a target board with mips VR4131 processor. The target board already having one boot loader on flash. Now I need to put my own boot loader which I modified according to the requirement on the flash. As I know MIPS have fixed starting address 0xbfc00000, how to change this address to other address so that after power on it can enter to the new address (my own boot loader).
Actual my own doesn’t have support for my target board, hence I modified the source code like initialization for cpu , sdram according to the KMC board. Now I want to put my code into FUJITSU flash memory for testing purpose, without overwrite the previous boot loader. After power on the board, instead of previous I need to run my modified bootloader.
I don’t have previous bootloader source code and much details about that. switch/jumper settings for remapping is not present in my target board manual.
But previous bootloader is giving command prompt successfully.

Q1. If I found an address and stored the second bootloader then After reset, how can I execute the second bootloader without executing the first bootloader?
canbumanikandan
 
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Postby kasi » Tue Apr 28, 2009 10:49 pm

hi,
> how to change this address to other address so that after power on it can enter to the new address

you have to modify the linker script of your bootloader this will make the bootloader to start from the specified offset rather than the default offset

can i know which boot loader your are using ?
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
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Bootloader names

Postby canbumanikandan » Tue Apr 28, 2009 11:23 pm

Previous bootloader= CMON
new and my modified bootloader = YAMON
canbumanikandan
 
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Re:how to change the MIPS bootloader start address

Postby kasi » Wed Apr 29, 2009 12:28 am

hi,
i am looking at the yamon-bin-02.16 archive.

from the reset-02.16.map file we can see that :

[bash] vim reset-02.16.map
Linker script and memory map

0x00000000bfc10000 _reset_handler_le = 0xbfc10000
0x00000000bfc78000 _reset_handler_be = 0xbfc78000

so you start at bfc10000.you hav to change this to the required offset in the linker script.
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
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question

Postby canbumanikandan » Wed Apr 29, 2009 12:37 am

hi,
Thanks for your reply.

In my flash ,I already have CMON bootloader. now I want to put my modified bootloader YAMON into flash memory.

you are giving ideas according to the YAMON bootloader.

How is it possible?


Regards,
Anbu Manikandan C
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Postby kasi » Wed Apr 29, 2009 1:17 am

> In my flash ,I already have CMON bootloader. now I want to put my modified bootloader
> YAMON into flash memory.

u cannot have two bootloaders on a single flash memory. you got to have two flash memories which u can change using some jumper settings for loading the required bootloader

how many types of flash memories u have on our board
.
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
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about flash

Postby canbumanikandan » Wed Apr 29, 2009 6:22 am

hi,


Only one type(FUJITSU) of flash memory.But I have Two separate flash memory IC's in the target board.



regards,
Anbu Manikandan C
canbumanikandan
 
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Re:about flash

Postby kasi » Wed Apr 29, 2009 12:01 pm

hi,

> Only one type(FUJITSU) of flash memory.But I have Two separate flash memory IC's in the target board.

are you telling that ur having both NOR and NAND flash on your board ?

can you give your board details so that i can get a clear picture before suggesting you what to do ..
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
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About board

Postby canbumanikandan » Wed Apr 29, 2009 9:28 pm

hi,


my target board is KMC(kyoto Microcomputers) board.It has two FUJITSU flash memory IC's with each 1MB physical memory.



Regards,
Anbu Manikandan C
canbumanikandan
 
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Re: About board

Postby kasi » Wed Apr 29, 2009 10:22 pm

hi,
> my target board is KMC(kyoto Microcomputers) board.It has two FUJITSU flash memory IC's with each 1MB physical memory.

good...

then by changing the jumper settings u can choose either one of them to be used for booting.look in the boards documentation manual for the jumper settings.

P.S: i am still not able to get your target board name .. i mean like KMC is the OEM but what is the exact name of the board. some pointers and links will be fine
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
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hi

Postby canbumanikandan » Thu Apr 30, 2009 1:57 am

hi,

my target board is mips NEC vr4131 processor board manufactured by KMC (Kyoto Microcomputers).But in board manual, I don't have jumper settings for change the flash memory address.but It has one jumper(for clk settings)and one switch(for CPU mode settings).





Regards,
Anbu manikandan C
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still cant get your board

Postby kasi » Thu Apr 30, 2009 3:48 am

hi,
> my target board is mips NEC vr4131 processor board manufactured by KMC (Kyoto Microcomputers)

the information we get from this is not about the target board but about the processor. so try to find the board name or whatever the alias is .. :)

> don't have jumper settings for change the flash memory address.but It has one jumper(for clk settings)and one switch(for CPU mode settings).

i think you dont have both NOR and NAND flash in your board.its a similar type flash split up into two parts
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
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hi

Postby canbumanikandan » Tue May 05, 2009 12:18 am

hi,

>i think you dont have both NOR and NAND flash in your board.its a similar type flash split up into two parts

exactly, you are right.

myboard name is same as that I mentioned previously . I referred with board manual also (KZP-VR4131-PCI-01----KMC board)
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Re: still cant get your board

Postby kasi » Tue May 05, 2009 3:11 am

hi,
> I referred with board manual also (KZP-VR4131-PCI-01----KMC board)

now i get it

what method ur using for flashing
Thanks and Warm Regards,
Kasiviswanathan.V
kasi
 
Posts: 18
Joined: Wed Feb 25, 2009 3:46 am

hi

Postby canbumanikandan » Tue May 05, 2009 4:11 am

hi,


I am using the old(cmon) bootloader prompt to flash the image file in to flash memory using fwrite command.



regards,
Anbu Manikandan C
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