AM6548: the address for loading the dtb from u-boot

Hi got more info for you gus 

So it looks like in the ./lib/lmb.c file if finds the reserved area but I assume it should look at the dts uboot file. But I can’t match how the calculation for the reserved area is done. I found out that the dtb is not loaded into the fdtcontroladdr but in a different region. I got the below dump from the lmb.c using the #define DEBUG and using lmb_debug function call. My question is how does the reserved areas gets calculated if you anybody can help me with that it would be great.  Below is the dump from when the kernel starts 

lmb_dump_all:

   memory.cnt             = 0x1

   memory.size           = 0x0

   memory.reg[0x0].base   = 0x80000000

                   .size   = 0x80000000

   reserved.cnt           = 0x3

   reserved.size         = 0x0

   reserved.reg[0x0].base = 0x80080000

                     .size = 0xdf0000

   reserved.reg[0x1].base = 0xfddc2000

                     .size = 0x115000

   reserved.reg[0x2].base = 0xfded7a40

                     .size = 0x21285c0

bootm_mapsize   =80000000   bootm_low     = 80000000

## device tree at 0000000082000000 ... 0000000082111fff (len=1134592 [0x115000])

   Loading Device Tree to 00000000fddc2000, end 00000000fded6fff ... OK

Thanks

Hi Mohsen,


https://gitlab.denx.de/u-boot/u-boot/-/blob/master/README
fdtcontroladdr- if set this is the address of the control flattened device tree used by U-Boot when CONFIG_OF_CONTROL is defined.

 fdtcontroladdr and that is for u-boot dtb and fdtaddr is used for Linux DTB loading. I believe now your question is more on reserved
memory regions? Can you just double confirm the exact question you want the answer for.

Is it how reserved memory regions are allocated?

- Keerthy

Hi Keerthy

I don't think that is true as i send you the output from u-boot. You can see that the fdt is loaded in section reserved.reg[0x1].base = 0xfddc2000 that is not the fdtcontroladdr. below you can see teh address for the 

fdtaddr=0x82000000
fdtcontroladdr=fded91f8

that is why i am asking for the location of the fdt and why the reserved memory is important. 

Hi Kreeth

below is what i have in the .config file

#
# Device Tree Control
#
CONFIG_OF_CONTROL=y

so what you are talking about is set but still it does not use it. I guess there must be something else that i am missing here. Please take  a look at what i have above, it shows where the fdt is loaded.

Thanks

Hi Mohsen,

Since we had a call on this topic, do you want to summarize and close this thread?

Regards

Karthik