Update for 2021.09.00

Modify branch to 2021.09 and add release notes for 2021.09.00.

Signed-off-by: David Abdurachmanov <[email protected]>

README.md

@@ -34,7 +34,7 @@ This needs to be done every time you want a clean setup based on the latest laye
 
 ```bash
 mkdir riscv-sifive && cd riscv-sifive
-repo init -u git://github.com/sifive/meta-sifive -b 2021.08 -m tools/manifests/sifive.xml
+repo init -u git://github.com/sifive/meta-sifive -b 2021.09 -m tools/manifests/sifive.xml
 repo sync
 ```
 

ReleaseNotes/2021.09.md

@@ -0,0 +1,23 @@
+# Release Notes for 2021.09.00
+
+This release includes major changes compared previous Freedom U SDK (FUSDK). The main changes include:
+
+- Layers (`openembedded-core`, `meta-openemedded`, `meta-riscv`, `meta-clang`,  `meta-tensorflow-lite`) were updated to their latest revisions.
+- `libinput` 1.17.0 was removed from `meta-sifive` layer. Newer version is now available from `openenmedded-core` layer.
+- `mesa` was updated to 21.2.1.
+- `stress-ng` was updated to 0.13.01.
+- `linux-mainline_5.13` (Linux kernel) was updated to v5.13.17.
+- `u-boot` was refactored and converted to bbappend instead of a modified copy from `openembedded-core` layer.
+- `tune-riscv.inc` was introduced in `meta-sifive` layer to provide two new options (`sifive-5-series` and `sifive-7-series`) which adds `-mtune=sifive-{5,7}-series` compiler options for all the packages.
+- Unmatched machine `DEFAULTTUNE` is now changed from `riscv64` to `sifive-7-series`. This setting can be changed in the local configuration file if the user wants to revert back to `riscv64`.
+- `opensbi` was updated to a git version (commit bd355213b).
+-  `glibc` was updated to 2.34.
+
+## Known Issues
+
+1. Newer OE/Yocto buildtools could cause build issues for `nspr-native` package. Use `-r yocto-3.2_M2 -t 20200729` as described in README file if you are using OE/Yocto buildtools. See Yocto bug [#14112](https://bugzilla.yoctoproject.org/show_bug.cgi?id=14112)
+2. We have found an issue with SanDisk "A2" microSD cards and thus do not recommend them.
+3. If the desktop is unresponsive/frozen (i.e. the keyboard doesn't work or/and the mouse doesn't work, the clock is not updating, etc.) try `systemctl restart display-manager` from the serial console.
+4. If the keyboard or/and mouse is not responsive/frozen check if the input device is available under `libinput list-devices` and if events are registered by `libinput debug-events` in the console. If events are registered try `systemctl restart display-manager` from the serial console. Otherwise manually unplug and plug the keyboard or/and mouse.
+5. If your desktop is very slow check Mesa OpenGL rendered (`glxinfo | grep OpenGL`). If it is `OpenGL renderer string: llvmpipe` restart the system. In rare cases Mesa might fallback to `llvmpipe`, but restart usually resolved the issue.
+6. Restart is not implemented in software for HiFive Unmatched.