[U-Boot] [PATCH] [DFU] Implement NAND dfu support

[Lukasz Majewski <l.majewski@samsung.com>]

Hi Scott,

> On 12/10/2012 09:24:32 AM, Pantelis Antoniou wrote:
> > Introduce on-the fly DFU NAND support.
> > 
> > Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
> > ---
> >  drivers/dfu/Makefile   |   1 +
> >  drivers/dfu/dfu.c      |   7 ++
> >  drivers/dfu/dfu_nand.c | 194  
> > +++++++++++++++++++++++++++++++++++++++++++++++++
> >  include/dfu.h          |  23 ++++++
> >  4 files changed, 225 insertions(+)
> >  create mode 100644 drivers/dfu/dfu_nand.c
> 
> What is DFU?  I don't see anything in README or doc/, despite there  
> already being CONFIG symbols for it.

DFU means Device Firmware Upgrade. It is a relatively simple protocol
to update firmware on the target (mainly with small files - e.g.
uImage).

For more information please skim:
http://www.usb.org/developers/devclass_docs/usbdfu10.pdf


> 
> > +static int nand_block_op(enum dfu_nand_op op, struct dfu_entity
> > *dfu,
> > +			u64 offset, void *buf, long *len)
> > +{
> > +	char cmd_buf[DFU_CMD_BUF_SIZE];
> > +	u64 start, count;
> > +	int ret;
> > +	int dev;
> > +	loff_t actual;
> > +
> > +	/* if buf == NULL return total size of the area */
> > +	if (buf == NULL) {
> > +		*len = dfu->data.nand.size;
> > +		return 0;
> > +	}
> > +
> > +	start = dfu->data.nand.start + offset + dfu->bad_skip;
> > +	count = *len;
> > +	if (start + count >
> > +			dfu->data.nand.start +
> > dfu->data.nand.size) {
> > +		printf("%s: block_op out of bounds\n", __func__);
> > +		return -1;
> > +	}
> > +	dev = nand_curr_device;
> > +	if (dev < 0 || dev >= CONFIG_SYS_MAX_NAND_DEVICE ||
> > +		!nand_info[dev].name) {
> > +		printf("%s: invalid nand device\n", __func__);
> > +		return -1;
> > +	}
> > +
> > +	sprintf(cmd_buf, "nand %s %p %llx %llx",
> > +		op == DFU_OP_READ ? "read" : "write",
> > +		 buf, start, count);
> > +
> > +	debug("%s: %s 0x%p\n", __func__, cmd_buf, cmd_buf);
> > +	ret = run_command(cmd_buf, 0);
> 
> Why not use the C interface to NAND?

We also support there eMMC (both with raw and file systems). Moreover
we had this discussion some time ago (if we shall use "command" or
native C API). 


> 
> > +	/* find out how much actual bytes have been written */
> > +	/* the difference is the amount of skip we must add from
> > now on */
> > +	actual = nand_extent_skip_bad(&nand_info[dev], start,
> > count);
> 
> ...especially since you already need to interact with it here?
> 
> -Scott



-- 
Best regards,

Lukasz Majewski

Samsung Poland R&D Center | Linux Platform Group