[U-Boot] uboot 2014-04 + gcc7+ = crash in net_set_ip_header (ping/tftp)

[Frank Wunderlich]

Hi,

i'm facing a problem in older uboot-code which may be fixed on newer, but i did not found the fixing commit yet. Maybe you can point me to it.

I need to use older code in this case because driver for mt7622 and other is not yet available for upstream uboot.

I have temporary changed optimization from -Os to -O1 which "fixes" the issue, currently i don't know why. Maybe you know more about it

I have found this Thread and tried to fix it with the packed-variant, but same crash happens again

http://u-boot.10912.n7.nabble.com/Data-Abort-with-gcc-7-1-td298217.html

my code (without last commit):
https://github.com/frank-w/u-boot/tree/bpi-r64

my try to fix:

diff --git a/Makefile b/Makefile
index fa9cbd50df..6c62f921a9 100755
--- a/Makefile
+++ b/Makefile
@@ -546,7 +546,7 @@ else

 endif # $(dot-config)

-KBUILD_CFLAGS += -Os #-fomit-frame-pointer
+KBUILD_CFLAGS += -Os -mno-unaligned-access #-fomit-frame-pointer

 ifdef BUILD_TAG
 KBUILD_CFLAGS += -DBUILD_TAG='"$(BUILD_TAG)"'
diff --git a/include/net.h b/include/net.h
index 0802fad876..f16b44def6 100644
--- a/include/net.h
+++ b/include/net.h
@@ -273,7 +273,7 @@ struct ip_hdr {
 /*
  *     Internet Protocol (IP) + UDP header.
  */
-struct ip_udp_hdr {
+struct __attribute__((__packed__)) ip_udp_hdr {
        uchar           ip_hl_v;        /* header length and version    */
        uchar           ip_tos;         /* type of service              */
        ushort          ip_len;         /* total length                 */


board is Bananapi R64 v0.1 (with rtl8367), code works with gcc4.8, 5.5, 6.3, but not with 7.3 and 8.3

regards Frank