nand_fileio_read() function

Reed-Solomon code This implements a (1023,1015) Reed-Solomon ECC code over GF(2^10) mod x^10 + x^3 + 1, shortened to (520,512). The ECC data consists of 8 10-bit symbols, or 10 8-bit bytes. Given 512 bytes of data, computes 10 bytes of ECC. This is done by converting the 512 bytes to 512 10-bit symbols (elements of F), interpreting those symbols as a polynomial in F[X] by taking symbol 0 as the coefficient of X^8 and symbol 511 as the coefficient of X^519, and calculating the residue of that polynomial divided by the generator polynomial, which gives us the 8 ECC symbols as the remainder. Finally, we convert the 8 10-bit ECC symbols to 10 8-bit bytes. The generator polynomial is hardcoded, as that is faster, but it can be computed by taking the primitive element a = x (in F), and constructing a polynomial in F[X] with roots a, a^2, a^3, ..., a^8 by multiplying the minimal polynomials for those roots (which are just 'x - a^i' for each i). Note: due to unfortunate circumstances, the bootrom in the Kirkwood SOC expects the ECC to be computed backward, i.e. from the last byte down to the first one.

nand_correct_data - Detect and correct a 1 bit error for 256 byte block

helper for parsing a nand device command argument string

Initialize the AT91SAM9 NAND controller.

Enable NAND device attached to a controller.

Disable NAND device attached to a controller.

Send a command to the NAND device.

Reset the AT91SAM9 NAND controller.

Send an address to the NAND device attached to an AT91SAM9 NAND controller.

Read data directly from the NAND device attached to an AT91SAM9 NAND controller.

Write data directly to the NAND device attached to an AT91SAM9 NAND controller.

Determine if the NAND device is ready by looking at the ready/~busy pin.

Read a block of data from the NAND device attached to an AT91SAM9. This utilizes the ARM hosted NAND read function.

Write a block of data to a NAND device attached to an AT91SAM9. This uses the ARM hosted write function to write the data.

Initialize an area for the OOB based on whether a user is requesting the OOB data. This determines the size of the OOB and allocates the space in case the user has not requested the OOB data.

Reads a page from an AT91SAM9 NAND controller and verifies using 1-bit ECC controller on chip. This makes an attempt to correct any errors that are encountered while reading the page of data.

Write a page of data including 1-bit ECC information to a NAND device attached to an AT91SAM9 controller. If there is OOB data to be written, this will ignore the computed ECC from the ECC controller.

Handle the initial NAND device command for AT91SAM9 controllers. This initializes much of the controller information struct to be ready for future reads and writes.