Fixed FPGA build for ubuntu 24.04 and add btb trashing test

[rosethompson]

Resolves issue #1040. Hopefully this time without the ECA error.
Also adds another test which forces the btb to trash. Jump and divide instructions alias to the same location such as btb is forced to miss on every access. Enough accesses are made so the I$ misses during one of these triggering a rare condition.

[jordancarlin]

The new test should probably be added to tests.vh so it is actually run during regression.

Looks like Vivado isn't officially supported on Ubuntu 24.04 yet (only 20.04 and 22.04) which is probably why there are issues. I wonder if symlinking the versions of ncurses that are installed in ubuntu 24.04 (v6 I think) to v5 would work instead. Not sure if there are breaking changes that prevent it from working with the newer versions though.

[rosethompson]

I'm running into more problems with ubuntu 24.04. glibc has issues with questa and imperasDV.
Additionally Vivado did not install the udev rules so it did not have the correct permissions to access the JTAG programming hardware. It works after manually installing and restarting udev. 24.04 is proving to be hassle.

[jordancarlin]

I've only tested regular tool flow and Verilator with 24.04, none of the proprietary tools. Hopefully it'll get better once there is official support for it from Vivado. What were the issues with Questa and ImpressDV?

[rosethompson]

This is error running lockstep questa version 2023.4_3 with ImperasDV.

# ** Fatal: (vsim-3828) Could not link 'vsim_auto_compile.so': cmd = '/opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/gcc -shared -fPIC -B/usr/lib/x86_64-linux-gnu -o "/tmp/rose@mustafar_dpi_48279/linux_x86_64_gcc-10.3.0/vsim_auto_compile.so"  "/tmp/rose@mustafar_dpi_48279/linux_x86_64_gcc-10.3.0/exportwrapper.o"   -Wl,-Bsymbolic -Wl,--wrap=uvm_hdl_check_path,--wrap=uvm_hdl_deposit,--wrap=uvm_hdl_force,--wrap=uvm_hdl_read,--wrap=uvm_hdl_release,--wrap=uvm_hdl_release_and_read '
# (vsim-50) A call to system(/opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/gcc -shared -fPIC -B/usr/lib/x86_64-linux-gnu -o "/tmp/rose@mustafar_dpi_48279/linux_x86_64_gcc-10.3.0/vsim_auto_compile.so"  "/tmp/rose@mustafar_dpi_48279/linux_x86_64_gcc-10.3.0/exportwrapper.o"   -Wl,-Bsymbolic -Wl,--wrap=uvm_hdl_check_path,--wrap=uvm_hdl_deposit,--wrap=uvm_hdl_force,--wrap=uvm_hdl_read,--wrap=uvm_hdl_release,--wrap=uvm_hdl_release_and_read  >'/tmp/questatmp.iFZOg9' 2>&1) returned error code '1'.
#    The logfile contains the following messages:
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: /lib/x86_64-linux-gnu/libc.so.6: unknown type [0x13] section `.relr.dyn'
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: skipping incompatible /lib/x86_64-linux-gnu/libc.so.6 when searching for /lib/x86_64-linux-gnu/libc.so.6
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: cannot find /lib/x86_64-linux-gnu/libc.so.6
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: /lib/x86_64-linux-gnu/libc.so.6: unknown type [0x13] section `.relr.dyn'
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: skipping incompatible /lib/x86_64-linux-gnu/libc.so.6 when searching for /lib/x86_64-linux-gnu/libc.so.6
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: /lib64/ld-linux-x86-64.so.2: unknown type [0x13] section `.relr.dyn'
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: skipping incompatible /lib64/ld-linux-x86-64.so.2 when searching for /lib64/ld-linux-x86-64.so.2
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: cannot find /lib64/ld-linux-x86-64.so.2
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: /lib64/ld-linux-x86-64.so.2: unknown type [0x13] section `.relr.dyn'
# /opt/mentor/questasim/gcc-10.3.0-linux_x86_64/bin/../libexec/gcc/x86_64-pc-linux-gnu/10.3.0/ld: skipping incompatible /lib64/ld-linux-x86-64.so.2 when searching for /lib64/ld-linux-x86-64.so.2
# collect2: error: ld returned 1 exit status

[davidharrishmc]

Should we just say that Ubuntu 24.04 isn't compatible with current Questa? Does the latest Questa make any difference?

[jordancarlin]

@rosethompson For Vivado on Ubuntu 24.04 I got the following to work instead of the more complicated install script:

ln -s /lib/x86_64-linux-gnu/libncurses.so.6 /lib/x86_64-linux-gnu/libncurses.so.5
ln -s /lib/x86_64-linux-gnu/libtinfo.so.6 /lib/x86_64-linux-gnu/libntinfo.so.5

It seems like it is looking for those specific names but works fine with the newer version. This way they will still get updated and managed by the system.

[rosethompson]

I like that fix for vivado. As for Questa I'm not able to run the latest version. The 2024 versions require a new license server and James had some issues getting running.

[rosethompson]

I'll take bin/vivado-ubuntu24.04-libs.sh out of the PR. Shall we add the symlinks to wally-tool-chain-install.sh? Jordan you probably know best where to put it.

[jordancarlin]

I'll take bin/vivado-ubuntu24.04-libs.sh out of the PR. Shall we add the symlinks to wally-tool-chain-install.sh? Jordan you probably know best where to put it.

Done in #1046

[jordancarlin]

Maybe we merge this for now and then open an issue to track the Questa problem with Ubuntu 24.04

[rosethompson]

That sounds like a good plan. I'll open an issue.