[coreboot] How to find out "page size" of a flash chip?
FENG Yu Ning
fengyuning1984 at gmail.com
Wed Nov 19 09:31:20 CET 2008
On 11/19/08, Peter Stuge <peter at stuge.se> wrote:
> The page_size member is considered an eraseblock size by the code.
Makes me clear. The naming is somewhat misleading, however.
> As you may have found, the code is pretty ugly overall.
The code does not look good.
int ich_spi_write(struct flashchip *flash, uint8_t * buf)
int i, j, rc = 0;
int total_size = flash->total_size * 1024;
int page_size = flash->page_size;
int erase_size = 64 * 1024;
the erase_size is "hard-wired" to 64k bytes.
2. Later in the same function, spi_block_erase_d8 is called to erase a
block(If we are going to use block erase, I agree with the FIXME
there). In fact, the erase-write loop covers the whole chip, I think
doing chip-erase outside is better. page_size is not used as erase
block size. It is used only as a write loop counter.
The ich spi read/write functions need to be written in the future.
> In the case
> of ichspi, read_page and write_page simply assume that it is possible
> to read or write all of page_size bytes in a loop.
If there is no other design issues, its only function here is just
> Other SPI "bus" drivers work differently, but page_size is always
> assumed to describe an eraseblock size.
Thanks very much for the clear explanation.
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