Add Scientific libs navigation and BLAS overview page.

List OpenBLAS improvements for U74 and X60 targets with links to
EasyBuild packages, upstream PRs, and EESSI walkthroughs.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: hugomeiland

README.md

@@ -12,4 +12,4 @@ See the [HPL results overview](apps/hpl.html) for a cross-board summary.
 - **[OrangePi RV2](boards/RV2.html)** — Ky X1 SoC, 8× SpacemiT X60. Native-arch HPL **7.38 GFLOP/s** (EESSI: DNF, RVV bug in OpenBLAS 0.3.30).
 - **[BananaPi F3](boards/F3.html)** — SpacemiT K1 SoC, 8× SpacemiT X60. HPL benchmarking in progress (EESSI: DNF, RVV bug in OpenBLAS 0.3.30).
 
-Use the menu above to jump to a board or app page.
+Use the menu above to jump to a board, app, or scientific lib page.

_config.yml

@@ -17,3 +17,7 @@ navigation_boards:
 navigation_apps:
   - title: HPL
     url: /apps/hpl.html
+
+navigation_scientific_libs:
+  - title: BLAS
+    url: /scientific-libs/blas.html

_includes/header.html

@@ -49,6 +49,22 @@ <h2 class="project-tagline">{{ site.description | default: "RISC-V learnings and
                     {% endfor %}
                 </ul>
             </div>
+
+            <div class="site-nav-group">
+                <span class="site-nav-label">Scientific libs</span>
+                <ul class="site-nav-list">
+                    {% for item in site.navigation_scientific_libs %}
+                    <li class="site-nav-item">
+                        <a
+                            href="{{ item.url | relative_url }}"
+                            class="site-nav-link{% if page.url == item.url %} is-active{% endif %}"
+                        >
+                            {{ item.title }}
+                        </a>
+                    </li>
+                    {% endfor %}
+                </ul>
+            </div>
         </div>
     </nav>
 </header>

apps/hpl.md

@@ -12,7 +12,7 @@ Cross-board summary of **High Performance Linpack (HPL)** runs on consumer RISC-
 
 **Before** — stock EESSI OpenBLAS 0.3.30 on each board.
 
-**After** — board-specific fixed OpenBLAS via EasyBuild, swapped in at runtime with FlexiBLAS (no HPL rebuild).
+**After** — board-specific fixed OpenBLAS via EasyBuild, swapped in at runtime with FlexiBLAS (no HPL rebuild). Details in the [BLAS overview](../scientific-libs/blas.html).
 
 On **VisionFive 2** (scalar U74), stock OpenBLAS uses a generic kernel; the fix adds a tuned U74 micro-kernel ([easyconfigs#26436](https://github.com/easybuilders/easybuild-easyconfigs/pull/26436), [EESSI/docs#818](https://github.com/EESSI/docs/pull/818)).
 

scientific-libs/blas.md

@@ -0,0 +1,28 @@
+# BLAS (OpenBLAS)
+
+Improvements to **OpenBLAS 0.3.30** on RISC-V boards in this project — built via EasyBuild, deployed through [EESSI](https://www.eessi.io/) with **FlexiBLAS** runtime swapping. See also the [HPL app](../apps/hpl.html) for end-to-end benchmark results.
+
+**Base stack:** GCC 14.3.0, OpenBLAS 0.3.30, EESSI `2025.06-001` ([`dev.eessi.io/riscv`](https://www.eessi.io/docs/repositories/dev.eessi.io-riscv/)).
+
+## Improvements
+
+| Board / CPU | Problem (stock 0.3.30) | Fix | Result |
+| ----------- | ---------------------- | --- | ------ |
+| [VisionFive 2](../boards/VisionFive2.html) — SiFive **U74** (scalar) | No U74 kernel; falls back to generic `RISCV64_GENERIC` C `2×2` GEMM | New **4×4 DGEMM micro-kernel** in RV64 assembly, `TARGET=U74` | Single-core DGEMM **~1.4 → 1.77 GFLOP/s**; 4-core DGEMM **6.31 GFLOP/s**; [HPL **1.69×**](../apps/hpl.html) |
+| [Orange Pi RV2](../boards/RV2.html) — SpacemiT **X60** (RVV VLEN=256) | RVV `gemv_n` zeroes an **uninitialized** vector register → `dgemv` returns NaN; HPL **fails** residual despite ~8.5 GFLOP/s | Backport upstream `gemv_n` fix; `TARGET=RISCV64_ZVL256B` | HPL **PASSED** (residual ~4e-03); peak **10.53 GFLOP/s** |
+| [Banana Pi F3](../boards/F3.html) — same K1 / X60 SoC | Same RVV `gemv_n` bug as RV2 | Same [easyconfigs#26444](https://github.com/easybuilders/easybuild-easyconfigs/pull/26444) fix | Fix applies; peak HPL not yet recorded |
+
+## Packages
+
+| Target | EasyBuild PR | Upstream OpenBLAS | Walkthrough |
+| ------ | ------------ | ----------------- | ----------- |
+| SiFive U74 | [easyconfigs#26436](https://github.com/easybuilders/easybuild-easyconfigs/pull/26436) | [OpenBLAS#5903](https://github.com/OpenMathLib/OpenBLAS/pull/5903) | [EESSI/docs#818](https://github.com/EESSI/docs/pull/818) |
+| SpacemiT X60 | [easyconfigs#26444](https://github.com/easybuilders/easybuild-easyconfigs/pull/26444) | [OpenBLAS#5408](https://github.com/OpenMathLib/OpenBLAS/pull/5408), [#5476](https://github.com/OpenMathLib/OpenBLAS/pull/5476) | [EESSI/docs#819](https://github.com/EESSI/docs/pull/819) |
+
+Build from a PR with `eb --from-pr <num> --robot` into an **EESSI-extend** user install, then register with `flexiblas add` / `flexiblas default` — no need to rebuild downstream apps like HPL.
+
+## Notes
+
+- **U74** — performance kernel; stock OpenBLAS works but leaves FP throughput on the table.
+- **X60** — correctness fix first: the stock EESSI `DYNAMIC_ARCH` build *does* dispatch RVV `ZVL256B` kernels, but 0.3.30's broken `gemv_n` makes HPL silently wrong. OpenBLAS **≥ 0.3.34** should carry the fix natively and improve RVV performance further.
+- On the experimental `dev.eessi.io/riscv` toolchain, pin a valid `-march` via `EASYBUILD_OPTARCH` when building (see board walkthroughs).