On Sun, Mar 21, 2010 at 06:13:44PM -0400, Sagar Heroorkar wrote:

Hi David,

I was exploring the ways to add partition into the blob dynamically.

I followd the following steps.

1. say we have 5 partitions. Flash size is 128mb

norflash@0,0{ 1---------- 2------------------ 3

---

5
  partition@f80000 {
                    label = "u_booot";
                    reg = <0xf80000 0x60000>;
                };

2. i am trying to add 6th partition dynamically in uboot.

   I used the the nodeoffset of norflash@0,0 which is parent offset wher i

want to create 6th partiton. I passed this parent offset to ret = fdt_add_subnode(blob,nodeoffset, "partition@6800000");

You should check ret for errors (< 0) before continuing.

    nodeoffset = ret;
    ptr[0] = 0x6800000;
    ptr[1] = 0x800000;

How is ptr declared?

    offset = 0x6800000;
    regs[0] += size_delta;

How is regs[0] initialized?

    memcpy(regs, ptr, plen);

Where did plen come from?

    ret = fdt_setprop(blob, nodeoffset, "reg", regs, plen);

You should check for errors here too.

I am printing the the blob later. i see that node is created but the last partition ie u-boot @ f80000 is going away.

the blob size is 8000 byes which we built using the

dtc -S 8000 -R 7 -I dts -O dtb -o file.dtb file.dts

Let me know if we need to increase size of the blob or something which i m missing. This is going to help a lot if you can reply.

For this case where there's a flash partition that's sometimes there and sometimes not, it might be simpler to put all the partitions, including the not-always-present ones in the dts. Then you can use fdt_nop_subnode() to remove the extra one on systems where it's not present.