2008-12-30 06:58:20     Memory map changes in 2008R1.5

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2008-12-30 06:58:20     Memory map changes in 2008R1.5

Hari Prasad (INDIA)

Message: 67203   

 

Hi,

 

Following is the memory map we get for 2007R1 kernel:

 

Memory map:

 

  text      = 0x00180000-0x0029a760

 

  init      = 0x0029b000-0x002a8b88

 

  data      = 0x002aea10-0x002e4c14

 

  stack     = 0x002b0000-0x002b2000

 

  bss       = 0x002e4c20-0x003917bc

 

  available = 0x003917bc-0x02f00000

 

  rootfs    = 0x02f00000-0x03f00000

 

  DMA Zone  = 0x03f00000-0x04000000

 

 

 

Incase of 2008R1.5 kernel, the memory map is as follows:

 

Memory map:

 

  text      = 0x00180000-0x002678e0

 

  rodata    = 0x00268000-0x002c246c

 

  data      = 0x002c3000-0x002d4000

 

    stack   = 0x002c4000-0x002c6000

 

  init      = 0x002d4000-0x00d88000

 

  bss       = 0x00d88000-0x00e34fb8

 

  available = 0x00e34fb8-0x03eff000

 

  DMA Zone  = 0x03f00000-0x04000000

 

When we compare the two memory maps, we can see that rootfs section is missing for 2008R1.5 kernel. When I tried to analyze the problem, I found (in the file linux-2.6.x/arch/blackfin/kernel/setup.c) that this section is defined only if the macro CONFIG_MTD_UCLINUX is defined. This macro definition is linked to the make menuconfig of 2008R1.5 kernel. The Kconfig file inside linux-2.6.x/drivers/mtd/maps has been modified such that this macro would be defined only for the product BF533-STAMP. But in 2007R1 kernel, this feature was provided for both BF533-EZKIT and BF533-STAMP. Could someone please clarify the following:

 

1. Why the KConfig has been changed to enable the macro CONFIG_MTD_UCLINUX only if product is BF533-STAMP?

 

2. If product is BF533-EZKIT, where exactly is rootfs present?

 

 

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2008-12-30 07:04:08     Re: Memory map changes in 2008R1.5

Mike Frysinger (UNITED STATES)

Message: 67204   

 

the uClinux MTD map is always available, but it is no longer the default.  enable it if you want it, or just use initramfs.

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2009-01-02 03:24:45     Re: Memory map changes in 2008R1.5

Hari Prasad (INDIA)

Message: 67282   

 

Hi Mike,

 

Am a newbie to uClinux and it would be of great help to me if you could let me know how to enable the MTD map in 2008R1.5 for BF533-EZKIT product.

 

Thanks.

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2009-01-02 03:42:46     Re: Memory map changes in 2008R1.5

Mike Frysinger (UNITED STATES)

Message: 67283   

 

the mtd layer is documented here:

http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:mtd

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