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Confused about the OMAP L138 Memory Address

liangzhu ma
Intellectual 320 points
Other Parts Discussed in Thread: OMAPL138

Hi, all

 

 

 

  • 0
    Intellectual 320 points

    Hi, all

    I've a OMAPL138 + NAND, my ubl, bootloader, kernel and rootfs are on the NAND.

     

    The TI said :

    0xc0700000 uImage

    0xc11800000 0x200000 0x400000 rootfs

     

    Question1:Does it mean when linux system booted, the uImage is load to 0xc070000, and the rootfs is loaded to 0xc1180000

    Question2: If the rootfs is too large, does it load the entire rootfs still ?

     

    ~~~~~~~~~~~~~~~~

     

    In the linux-kernel said,

    x000000000000-0x000000020000 : "u-boot env"    128k

    0x000000020000-0x000000040000 : "UBL" 128k

    0x000000040000-0x0000000c0000 : "u-boot"        512k

    0x000000200000-0x000000600000 : "kernel"        4m  

    0x000000600000-0x000040000000 : "filesystem"     1018m

     

    In the Nand flash_writer said.

    if (armubl == 1) 

    {

    gNandBoot.magicNum    = UBL_MAGIC_BIN_IMG

    gNandBoot.block       = 2

    gNandBoot.entryPoint  = 0x80000000;       

    gNandBoot.ldAddress   = 0x80000000;   

    } 

    else if (uboot == 1)

     {

    gNandBoot.magicNum    = UBL_MAGIC_DMA;

    gNandBoot.block       = 2;

    gNandBoot.entryPoint  = 0xc1080000;      

    gNandBoot.ldAddress   = 0xc1080000;

     

    Question 3:  What does u-boot env" mean?

    Question 4: the UBL block and UBOOT block are all 2 in the "nand-flash-writer", but they have different address in NAND-partions, why?

    Question5: 0x80000000 is used for UBL but the DSP-Arm-shared_mem alse use this address, why? 

     

    Thank you  

  • 0 in reply to liangzhu ma
    TI__Intellectual 1380 points

    Hi,

        I will try to answer your question as much as I can.

    Question1:Does it mean when linux system booted, the uImage is load to 0xc070000, and the rootfs is loaded to 0xc1180000

    Answer: Yes.


    Question2: If the rootfs is too large, does it load the entire rootfs still ?

    Answer: in this case, the rootfs is a ramdisk. So it is not supposed to be too large to be accommodated in DDR.

     

    Question 3:  What does u-boot env" mean?

    Answer: it means the environment/configuration parameters to be processed by U-Boot, i.e. "bootcmd = ...", "bootargs = ..." etc. They will need to be stored too.


    Question 4: the UBL block and UBOOT block are all 2 in the "nand-flash-writer", but they have different address in NAND-partions, why?

    Answer: I don't have an answer right now. I will check and answer you back.


    Question5: 0x80000000 is used for UBL but the DSP-Arm-shared_mem alse use this address, why?

    Answer: it means UBL is using this shared memory as temporary buffer. After the UBL completes, the application can use it.