u-boot/drivers/dfu/dfu_ram.c
Stephen Warren 0e285b503c dfu: fix some issues with reads/uploads
DFU read support appears to rely upon dfu->read_medium() updating the
passed-by-reference len parameter to indicate the remaining size
available for reading.

dfu_read_medium_mmc() never does this, and the implementation of
dfu_read_medium_nand() will only work if called just once; it hard-codes
the value to the total size of the NAND device irrespective of read
offset.

I believe that overloading dfu->read_medium() is confusing. As such,
this patch introduces a new function dfu->get_medium_size() which can
be used to explicitly find out the medium size, and nothing else.
dfu_read() is modified to use this function to set the initial value for
dfu->r_left, rather than attempting to use the side-effects of
dfu->read_medium() for this purpose.

Due to this change, dfu_read() must initially set dfu->b_left to 0, since
no data has been read.

dfu_read_buffer_fill() must also be modified not to adjust dfu->r_left
when simply copying data from dfu->i_buf_start to the upload request
buffer. r_left represents the amount of data left to be read from HW.
That value is not affected by the memcpy(), but only by calls to
dfu->read_medium().

After this change, I can read from either a 4MB or 1.5MB chunk of a 4MB
eMMC boot partion with CONFIG_SYS_DFU_DATA_BUF_SIZE==1MB. Without this
change, attempting to do that would result in DFU read returning no data
at all due to r_left never being set.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
2014-08-09 11:16:58 -04:00

78 lines
1.7 KiB
C

/*
* (C) Copyright 2013
* Afzal Mohammed <afzal.mohd.ma@gmail.com>
*
* Reference: dfu_mmc.c
* Copyright (C) 2012 Samsung Electronics
* author: Lukasz Majewski <l.majewski@samsung.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <malloc.h>
#include <errno.h>
#include <dfu.h>
static int dfu_transfer_medium_ram(enum dfu_op op, struct dfu_entity *dfu,
u64 offset, void *buf, long *len)
{
if (dfu->layout != DFU_RAM_ADDR) {
error("unsupported layout: %s\n", dfu_get_layout(dfu->layout));
return -EINVAL;
}
if (offset > dfu->data.ram.size) {
error("request exceeds allowed area\n");
return -EINVAL;
}
if (op == DFU_OP_WRITE)
memcpy(dfu->data.ram.start + offset, buf, *len);
else
memcpy(buf, dfu->data.ram.start + offset, *len);
return 0;
}
static int dfu_write_medium_ram(struct dfu_entity *dfu, u64 offset,
void *buf, long *len)
{
return dfu_transfer_medium_ram(DFU_OP_WRITE, dfu, offset, buf, len);
}
long dfu_get_medium_size_ram(struct dfu_entity *dfu)
{
return dfu->data.ram.size;
}
static int dfu_read_medium_ram(struct dfu_entity *dfu, u64 offset,
void *buf, long *len)
{
return dfu_transfer_medium_ram(DFU_OP_READ, dfu, offset, buf, len);
}
int dfu_fill_entity_ram(struct dfu_entity *dfu, char *s)
{
char *st;
dfu->dev_type = DFU_DEV_RAM;
st = strsep(&s, " ");
if (strcmp(st, "ram")) {
error("unsupported device: %s\n", st);
return -ENODEV;
}
dfu->layout = DFU_RAM_ADDR;
dfu->data.ram.start = (void *)simple_strtoul(s, &s, 16);
s++;
dfu->data.ram.size = simple_strtoul(s, &s, 16);
dfu->write_medium = dfu_write_medium_ram;
dfu->get_medium_size = dfu_get_medium_size_ram;
dfu->read_medium = dfu_read_medium_ram;
dfu->inited = 0;
return 0;
}