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xPack GNU RISC-V Embedded GCC v8.3.0-1.1 released

· 5 min read
Liviu Ionescu (ilg)
Liviu Ionescu (ilg)

Version 8.3.0-1.1 is a new release of the xPack GNU RISC-V Embedded GCC, following SiFive release from August 2019.

Download​

The binary files are available from GitHub Releases.

Install​

The easiest way to install this specific version, is by using xpm:

xpm install @xpack-dev-tools/riscv-none-elf-gcc@8.3.0-1.1.1 -verbose

The full details of installing the xPack GNU RISC-V Embedded GCC on various platforms can be found in the Install Guide.

Compliance​

Starting with v8.2.0-2, this distribution closely follows the official SiFive Freedom Tools distribution.

This release is based on the v2019.08.0 release, and includes the SiFive extensions (like CLIC interrupts and a an even larger multi-lib set).

The following commits (from sifive/freedom-tools) were used:

GDB was upstreamed and does not require SiFive specific patches, so the current build uses git://sourceware.org/git/binutils-gdb.git, the 9b40759 commit from 28 Feb 2019.

Supported libraries​

The supported libraries are:

$ riscv-none-embed-gcc -print-multi-lib
.;
rv32e/ilp32e;@march=rv32e@mabi=ilp32e
rv32ea/ilp32e;@march=rv32ea@mabi=ilp32e
rv32em/ilp32e;@march=rv32em@mabi=ilp32e
rv32eac/ilp32e;@march=rv32eac@mabi=ilp32e
rv32emac/ilp32e;@march=rv32emac@mabi=ilp32e
rv32i/ilp32;@march=rv32i@mabi=ilp32
rv32ia/ilp32;@march=rv32ia@mabi=ilp32
rv32im/ilp32;@march=rv32im@mabi=ilp32
rv32if/ilp32f;@march=rv32if@mabi=ilp32f
rv32ifd/ilp32d;@march=rv32ifd@mabi=ilp32d
rv32iaf/ilp32f;@march=rv32iaf@mabi=ilp32f
rv32iafd/ilp32d;@march=rv32iafd@mabi=ilp32d
rv32imaf/ilp32f;@march=rv32imaf@mabi=ilp32f
rv32imf/ilp32f;@march=rv32imf@mabi=ilp32f
rv32imfd/ilp32d;@march=rv32imfd@mabi=ilp32d
rv32iac/ilp32;@march=rv32iac@mabi=ilp32
rv32imac/ilp32;@march=rv32imac@mabi=ilp32
rv32imafc/ilp32f;@march=rv32imafc@mabi=ilp32f
rv32imafdc/ilp32d;@march=rv32imafdc@mabi=ilp32d
rv64i/lp64;@march=rv64i@mabi=lp64
rv64ia/lp64;@march=rv64ia@mabi=lp64
rv64im/lp64;@march=rv64im@mabi=lp64
rv64if/lp64f;@march=rv64if@mabi=lp64f
rv64ifd/lp64d;@march=rv64ifd@mabi=lp64d
rv64iaf/lp64f;@march=rv64iaf@mabi=lp64f
rv64iafd/lp64d;@march=rv64iafd@mabi=lp64d
rv64imf/lp64f;@march=rv64imf@mabi=lp64f
rv64imaf/lp64f;@march=rv64imaf@mabi=lp64f
rv64iac/lp64;@march=rv64iac@mabi=lp64
rv64imac/lp64;@march=rv64imac@mabi=lp64
rv64imafc/lp64f;@march=rv64imafc@mabi=lp64f
rv64imafdc/lp64d;@march=rv64imafdc@mabi=lp64d

Bug fixes​

  • [#3] Due to an omission in the build scripts, the content of the libgcov library was mostly empty; the script was fixed and now the library has the expected content.
  • [#4] Due to a bug in the build scripts, the Windows binaries included two copies of the docs folder, one in root and one in the share folder; the script was fixed and now there is only one copy in share/docs.

Improvements​

Compared to the original SiFive version, the same architecture and API options are supported, and there are minimal functional changes

  • libgloss was removed from the list of libraries always linked to the application, since it issues ECALL instructions that fail in bare metal environments
  • march=rv32imaf/mabi=ilp32f was added to the list of multi-libs
  • the standard documentation, in PDF and HTML, is included
  • experimental support for Python in GDB was added

newlib-nano​

Support for newlib-nano is available using the --specs=nano.specs option. For better results, this option must be added to both compile and link time.

nosys.specs​

If no syscalls are needed, --specs=nosys.specs can be used at link time to provide empty implementations for the POSIX system calls.

Compile options​

The libraries are compiled with -O2 -mcmodel=medany. The nano version is compiled with -Os -mcmodel=medany.

caution

It is mandatory for the applications to be compiled with -mcmodel=medany, otherwise the link will fail.

Known problems​

  • [#5] the riscv-none-embed-gdb-py fails to start on Ubuntu (and possibly other Debian) systems, it fails with a message like:
$ PYTHONHOME=/usr PYTHONPATH=/usr/lib/python2.7 riscv-none-embed-gdb-py --version
Traceback (most recent call last):
  File "/usr/lib/python2.7/site.py", line 554, in <module>
    main()
  File "/usr/lib/python2.7/site.py", line 536, in main
    known_paths = addusersitepackages(known_paths)
  File "/usr/lib/python2.7/site.py", line 272, in addusersitepackages
    user_site = getusersitepackages()
  File "/usr/lib/python2.7/site.py", line 247, in getusersitepackages
    user_base = getuserbase() # this will also set USER_BASE
  File "/usr/lib/python2.7/site.py", line 237, in getuserbase
    USER_BASE = get_config_var('userbase')
  File "/usr/lib/python2.7/sysconfig.py", line 587, in get_config_var
    return get_config_vars().get(name)
  File "/usr/lib/python2.7/sysconfig.py", line 533, in get_config_vars
    _init_posix(_CONFIG_VARS)
  File "/usr/lib/python2.7/sysconfig.py", line 417, in _init_posix
    from _sysconfigdata import build_time_vars
  File "/usr/lib/python2.7/_sysconfigdata.py", line 6, in <module>
    from _sysconfigdata_nd import *
ImportError: No module named _sysconfigdata_nd

The problem is caused by gdb-py not being able to locate the Python system libraries, split into multiple packages and installed in multiple folders.

The workaround is to pass the Python environment to gdb-py:

PYTHONPATH="$(python -c 'import os; import sys; print(os.pathsep.join(sys.path))')" \
PYTHONHOME="$(python -c 'import sys; print(sys.prefix)')"

Documentation​

The original PDF documentation is available in the share/doc folder.

Supported platforms​

Binaries for Windows, macOS and GNU/Linux are provided.

The binaries were built using the xPack Build Box (XBB), a set of build environments based on slightly older distributions, that should be compatible with most recent systems.

  • x86/x64 GNU/Linux: all binaries were built with GCC 7.4, running in a CentOS 6 Docker container
  • x86/x64 Windows: all binaries were built with mingw-w64 GCC 7.4, running in a CentOS 6 Docker container
  • x64 macOS: most binaries were built with GCC 7.4, running in a separate folder on macOS 10.10.5; GDB cannot be compiled with GCC, so Apple clang was used.

Tests​

The binaries were testes on Windows 10 Pro 32/64-bit, Ubuntu 18 LTS 64-bit, Xubuntu 18 LTS 32-bit and macOS 10.14.

The tests consist in building and debugging some simple Eclipse projects available in the build project.

Since the source code used for GCC is identical to the one used by SiFive, the long and complex tests performed by SiFive to validate their release were not executed again.

Checksums​

The SHA-256 hashes for the files are:

532f719c11f7311a0103eac6ddd7dd012716a2c3030dd1ee7e64374b1af41d34
xpack-riscv-none-embed-gcc-8.3.0-1.1-darwin-x64.tgz

c40d8e74a3f87839131287ecd68be2e691c84af0b75d684c1e47ab60687ff987
xpack-riscv-none-embed-gcc-8.3.0-1.1-linux-x32.tgz

7b95d397a2bd319892f5c930757f7b3bc47acac633dafcf055b0901172513c00
xpack-riscv-none-embed-gcc-8.3.0-1.1-linux-x64.tgz

5d608a0438c5f5c4a2c8b6d4eb13499a60a17618da04fb20972eb0f4965ed4bd
xpack-riscv-none-embed-gcc-8.3.0-1.1-win32-x32.zip

10443f00627473f08c44fd00c8011b17c67953d1eb4f1609fb00e5653165d5d3
xpack-riscv-none-embed-gcc-8.3.0-1.1-win32-x64.zip

Download analytics​

Credit to Shields IO for the badges and to Somsubhra/github-release-stats for the individual file counters.