static int alt_epcs_flash_memcmp(
alt_flash_dev* flash_info,
const void* src_buffer,
int offset,
size_t n
)
{
/*
* Compare chunks of memory at a time, for better serial-flash
* read efficiency.
*/
alt_u8 chunk_buffer[32];
const int chunk_size = sizeof(chunk_buffer) / sizeof(*chunk_buffer);
int current_offset = 0;
while (n > 0)
{
int this_chunk_size = n > chunk_size ? chunk_size : n;
int this_chunk_cmp;
if (
alt_epcs_flash_read(
flash_info,
offset + current_offset,
chunk_buffer,
this_chunk_size
) < 0
)
{
/*
* If the read fails, I'm not sure what the appropriate action is.
* Compare success seems wrong, so make it compare fail.
*/
return -1;
}
/* Compare this chunk against the source memory buffer. */
this_chunk_cmp = memcmp(&((unsigned char*)(src_buffer))[current_offset], chunk_buffer, this_chunk_size);
if (this_chunk_cmp)
{
return this_chunk_cmp;
}
n -= this_chunk_size;
current_offset += this_chunk_size;
}
/*
* If execution made it to this point, compare is successful.
*/
return 0;
}
static Cyg_ErrNo
epcs_bread( cyg_io_handle_t handle, void *buf, cyg_uint32 *len, cyg_uint32 pos)
{
struct alt_flash_dev *flash_info = (alt_flash_dev *)p_epcs_fd;
return alt_epcs_flash_read(flash_info, pos, buf, *len);
} // epcs_bread()
