Nand with 256 oob

[Raphaël Poggi]

Hi all !

I want to use barebox with nand support (Soft ECC) on a custom board
based on SAM9M10, but the nand has a 256 oob size and it is not
supported on barebox.

Barebox fails, because there is no oob scheme defined for 256 size.

if (!chip->ecc.layout && (chip->ecc.mode != NAND_ECC_SOFT_BCH)) {
switch (mtd->oobsize) {
case 8:
chip->ecc.layout = &nand_oob_8;
break;
case 16:
chip->ecc.layout = &nand_oob_16;
break;
case 64:
chip->ecc.layout = &nand_oob_64;
break;
case 128:
chip->ecc.layout = &nand_oob_128;
break;
default:
pr_warn("No oob scheme defined for oobsize %d\n",
  mtd->oobsize);
BUG();
}
}


I have found this oob_256 scheme but I don't know if it's correct or not.

static struct nand_ecclayout nand_oob_256 = {
.eccbytes = 96,
.eccpos = {
160, 161, 162, 163, 164, 165, 166, 167,
168, 169, 170, 171, 172, 173, 174, 175,
   176, 177, 178, 179, 180, 181, 182, 183,
   184, 185, 186, 187, 188, 189, 190, 191,
   192, 193, 194, 195, 196, 197, 198, 199,
   200, 201, 202, 203, 204, 205, 206, 207,
   208, 209, 210, 211, 212, 213, 214, 215,
   216, 217, 218, 219, 220, 221, 222, 223,
   224, 225, 226, 227, 228, 229, 230, 231,
   232, 233, 234, 235, 236, 237, 238, 239,
   240, 241, 242, 243, 244, 245, 246, 247,
   248, 249, 250, 251, 252, 253, 254, 255},
.oobfree = {
{.offset = 2,
.length = 158}}
};

Can we use this scheme ? Or there is another solution ?

Thanks,
Raphaël