how to load linux kernel image address into boot loader

[gopintj]

Hi all.

Currently, i am learning Embedded linux in which i am supposed to create a kernel image along with u-boot image and have to load it into ARM development board. I have successfully compiled linux kernel 3.8.5. After this, i need to create a u boot image. I am planning to create this uImage file using "mkimage" command.

Here are my questions.

1. By using "mkimage" command, how can i make my uImage file tobe burned into my processor's reset vector address?
2. what do "-a" and "-e" in mkimage command mean?
3. will uImage automatically get kernel image and load it into RAM once after i download this uImage into flash? If No, how do i have to program the boot loader to get and load kernel image into RAM in my target board.?

 

[Arun M]

Here is the man page for mkImage: https://linux.die.net/man/1/mkimage

mkImage is used to create linux image for use with U-Boot Bootloader.

Example : mkimage -A arm -C none -O linux -T kernel -d zImage -a 0x00010000 -e 0x00010000 zImage.uimg

-a refers to the load address
-e refers to the entry point

these two refer to from where the kernel is loaded.

You can also create a uImage for uncompressed version.


May I know which board are you using?

 

[gopintj]

I use Mini2440 development kit.

Could you please explain me about how to burn my zImage and uImage files into my development board via TFTP or by any other method?

I have created a zImage using make ARCH=arm CROSS_COMPILE=/(Location of the boof folder of arm folder of the kernel)
After this, i created uImage by giving -a 0xfffffff2 -e 0xfffffff2 values in mkimage command. Here is my doubt. What do these two values really do. What should be the load address and entry point for my board?

 

[Arun M]

If you are using Mini2440 then you may want to refer the user's manual of it..

Refer to page 251 in the following document.

http://www.hiteg.com/downloads/mini2440v2/MINI2440v1.pdf.zip

 

[gopintj]

Hi mr Arun.

I have one more doubt. Without switching to NAND flash, i need to boot my mini2440 via a SD Card. For this, i have googled many times and found few steps.

In some of the websites, they mentioned to create 2 new partitions (BOOT and RFS) partitions in which BOOT partition should be formatted with FAT 32 file system and RFS(Root file system) should be formatted in ext3 format. I have done these formatting and copied Root file system files into RFS folder.

Whats my doubt in this is, in that website which i got this information, they asked me to copy u-boot.bin file (which is the file to execute u-Boot directly) and kernel image (uImage) into the BOOT folder.

While i copied these two files and put my SD card into my mini2440(switch directing to NOR flash), i couldn't get anything booting. I am getting the normal super vivi display.

Do we have to add anyother script files into BOOT folder of SD card in order to make things work?