On Wed, Jun 8, 2016 at 11:52 AM, <yegorslists@xxxxxxxxxxxxxx> wrote:
> From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
>
> During checksum calculation in ftdi_eeprom_build() a 16-bit value
> will be read directly from EEPROM (FT230X devices only):
>
> ftdi_read_eeprom_location(ftdi, i, &data)
>
> 'data' is little endian, so the bytes must be swapped on a big-endian
> system. Introduce related macro swap_short() and add endianess detection
> to CMakeLists.txt.
> ---
> CMakeLists.txt | 7 +++++++
> src/ftdi.c | 2 +-
> src/ftdi_i.h | 5 +++++
> 3 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/CMakeLists.txt b/CMakeLists.txt
> index ce122ff..3cb2f3f 100644
> --- a/CMakeLists.txt
> +++ b/CMakeLists.txt
> @@ -22,6 +22,13 @@ if(${CMAKE_BUILD_TYPE} STREQUAL Debug)
> add_definitions(-DDEBUG)
> endif(${CMAKE_BUILD_TYPE} STREQUAL Debug)
>
> +# check, if he system is big endian or little endian
> +include(TestBigEndian)
> +test_big_endian(BIGENDIAN)
> +if(${BIGENDIAN})
> + add_definitions(-DBIGENDIAN)
> +endif(${BIGENDIAN})
> +
> # find libusb
> find_package ( USB1 REQUIRED )
> include_directories ( ${LIBUSB_INCLUDE_DIR} )
> diff --git a/src/ftdi.c b/src/ftdi.c
> index f5d263c..f516538 100644
> --- a/src/ftdi.c
> +++ b/src/ftdi.c
> @@ -3239,7 +3239,7 @@ int ftdi_eeprom_build(struct ftdi_context *ftdi)
> fprintf(stderr, "Reading Factory Configuration Data
> failed\n");
> i = 0x50;
> }
> - value = data;
> + value = swap_short(data);
> }
> else {
> value = output[i*2];
> diff --git a/src/ftdi_i.h b/src/ftdi_i.h
> index cf2ac78..a9ab3a6 100644
> --- a/src/ftdi_i.h
> +++ b/src/ftdi_i.h
> @@ -141,3 +141,8 @@ struct ftdi_eeprom
> int release_number;
> };
>
> +#if BIGENDIAN
> +#define swap_short(val) ((val >> 8) | (val << 8))
> +#else
> +#define swap_short(val) (val)
> +#endif
> --
> 2.1.4
This patch should be replaced by this one:
http://developer.intra2net.com/mailarchive/html/libftdi/2016/msg00068.html
Yegor
--
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