732: revise aarch64 support r=stlankes a=stlankes

- add TLS support
- revise processor detection
- add function to switch the context
- revise stack handling
- initialize interrupt controller

Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

- add TLS support
- revise processor detection
- add function to switch the context
- revise stack handling

- in addition, add some comments

731: don't leak memory if the environment is empty r=stlankes a=stlankes



Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

730: remove trailing null characters r=stlankes a=stlankes

- revert also #729 

Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

- this character isn't required

This reverts commit f677532b.

729: remove typo r=stlankes a=stlankes



Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

728: move hardware independent function is_uhyve to env r=stlankes a=stlankes



Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

726: remove obsolete function `detect_from_uhyve` r=jounathaen a=stlankes

- minor improvements to #725
- removing obsolete code

Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

725: don't initialize IO-APIC for uhyve r=jounathaen a=stlankes

uhyve doesn't support a common IO-APIC. Consequently, libhermit should not initialize the IO-APIC

Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

uhyve doesn't support a common IO-APIC. Consequently, libhermit
should not initialize the IO-APIC

724: add check if the idle task has to give up the processor r=stlankes a=stlankes

- simplifies the run function of the scheduler
- avoids unneeded calls of the function `schedule`

Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

- only the idle task should call `run`
- consequently, the idle task check can be removed

723: remove deprecated functions and use hermit-dtb from crates.io r=stlankes a=stlankes



Co-authored-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>

719: Add basic docs for timer and semaphore syscalls r=stlankes a=nathanwhyte

Helping with issue #353

Added _(very)_ basic documentation to syscalls in [`timer.rs`](https://github.com/hermitcore/libhermit-rs/blob/master/src/syscalls/timer.rs) and [`semaphore.rs`](https://github.com/hermitcore/libhermit-rs/blob/master/src/syscalls/semaphore.rs

)

I used Linux man pages as a reference when writing these.

Co-authored-by: Nathan Whyte <nathanwhyte35@gmail.com>

721: build(deps): bump bitflags from 2.1.0 to 2.2.1 r=mkroening a=dependabot[bot]

Bumps [bitflags](https://github.com/bitflags/bitflags) from 2.1.0 to 2.2.1.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/bitflags/bitflags/releases">bitflags's releases</a>.</em></p>
<blockquote>
<h2>2.2.1</h2>
<h2>What's Changed</h2>
<ul>
<li>Refactor attribute filtering to apply per-flag by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/345">bitflags/bitflags#345</a></li>
<li>Prepare for 2.2.1 release by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/346">bitflags/bitflags#346</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a href="https://github.com/bitflags/bitflags/compare/2.2.0...2.2.1">https://github.com/bitflags/bitflags/compare/2.2.0...2.2.1</a></p>
<h2>2.2.0 (yanked)</h2>
<h2>What's Changed</h2>
<ul>
<li>Create SECURITY.md by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/338">bitflags/bitflags#338</a></li>
<li>add docs to describe the behavior of multi-bit flags by <a href="https://github.com/nicholasbishop"><code>`@​nicholasbishop</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/340">bitflags/bitflags#340</a></li>
<li>Add support for bytemuck by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/336">bitflags/bitflags#336</a></li>
<li>Add a top-level macro for filtering attributes by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/341">bitflags/bitflags#341</a></li>
<li>Prepare for 2.2.0 release by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/342">bitflags/bitflags#342</a></li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a href="https://github.com/nicholasbishop"><code>`@​nicholasbishop</code></a>` made their first contribution in <a href="https://redirect.github.com/bitflags/bitflags/pull/340">bitflags/bitflags#340</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a href="https://github.com/bitflags/bitflags/compare/2.1.0...2.2.0">https://github.com/bitflags/bitflags/compare/2.1.0...2.2.0</a></p>
</blockquote>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/bitflags/bitflags/blob/main/CHANGELOG.md">bitflags's changelog</a>.</em></p>
<blockquote>
<h1>2.2.1</h1>
<h2>What's Changed</h2>
<ul>
<li>Refactor attribute filtering to apply per-flag by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/345">bitflags/bitflags#345</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a href="https://github.com/bitflags/bitflags/compare/2.2.0...2.2.1">https://github.com/bitflags/bitflags/compare/2.2.0...2.2.1</a></p>
<h1>2.2.0</h1>
<h2>What's Changed</h2>
<ul>
<li>Create SECURITY.md by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/338">bitflags/bitflags#338</a></li>
<li>add docs to describe the behavior of multi-bit flags by <a href="https://github.com/nicholasbishop"><code>`@​nicholasbishop</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/340">bitflags/bitflags#340</a></li>
<li>Add support for bytemuck by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/336">bitflags/bitflags#336</a></li>
<li>Add a top-level macro for filtering attributes by <a href="https://github.com/KodrAus"><code>`@​KodrAus</code></a>` in <a href="https://redirect.github.com/bitflags/bitflags/pull/341">bitflags/bitflags#341</a></li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a href="https://github.com/nicholasbishop"><code>`@​nicholasbishop</code></a>` made their first contribution in <a href="https://redirect.github.com/bitflags/bitflags/pull/340">bitflags/bitflags#340</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a href="https://github.com/bitflags/bitflags/compare/2.1.0...2.2.0">https://github.com/bitflags/bitflags/compare/2.1.0...2.2.0</a></p>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/bitflags/bitflags/commit/0c318c0d77ed63ad4ee9bfdf1d2c486993b18b37"><code>0c318c0</code></a> Merge pull request <a href="https://redirect.github.com/bitflags/bitflags/issues/346">#346</a> from KodrAus/cargo/2.2.1</li>
<li><a href="https://github.com/bitflags/bitflags/commit/a51c0532865ccd26de1a55d212ba90304199c463"><code>a51c053</code></a> prepare for 2.2.1 release</li>
<li><a href="https://github.com/bitflags/bitflags/commit/638707f0f0a38499dbc4cfdd7ef10d8106647309"><code>638707f</code></a> Merge pull request <a href="https://redirect.github.com/bitflags/bitflags/issues/345">#345</a> from KodrAus/fix/recursion</li>
<li><a href="https://github.com/bitflags/bitflags/commit/f3f3b6a7b00f79e05601afe07fe806d36fddd846"><code>f3f3b6a</code></a> add docs to example generated flags</li>
<li><a href="https://github.com/bitflags/bitflags/commit/588d13298ea5ba0ab37c57c947e0a47fe5335c8a"><code>588d132</code></a> refactor attribute filtering to apply per-flag</li>
<li><a href="https://github.com/bitflags/bitflags/commit/cbcafa710fc31172511e62efa06ad9eb214e4734"><code>cbcafa7</code></a> Merge pull request <a href="https://redirect.github.com/bitflags/bitflags/issues/342">#342</a> from KodrAus/cargo/2.2.0</li>
<li><a href="https://github.com/bitflags/bitflags/commit/61df53a791cfdd681bc4adcea12796c0bdef1ca5"><code>61df53a</code></a> prepare for 2.2.0 release</li>
<li><a href="https://github.com/bitflags/bitflags/commit/780f456840a2c2755b574397b3297e213a1e8b9f"><code>780f456</code></a> Merge pull request <a href="https://redirect.github.com/bitflags/bitflags/issues/341">#341</a> from KodrAus/fix/doc-alias</li>
<li><a href="https://github.com/bitflags/bitflags/commit/405e7de8ee8d9fea1ecf67a7bd234a9bcf45c3b9"><code>405e7de</code></a> updates macro field names</li>
<li><a href="https://github.com/bitflags/bitflags/commit/561fe509b081b2bf4d71a279389a03b9c3207b01"><code>561fe50</code></a> add a top-level macro for filtering attributes</li>
<li>Additional commits viewable in <a href="https://github.com/bitflags/bitflags/compare/2.1.0...2.2.1">compare view</a></li>
</ul>
</details>
<br />


[![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=bitflags&package-manager=cargo&previous-version=2.1.0&new-version=2.2.1)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores

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720: build(deps): bump dsaltares/fetch-gh-release-asset from 1.1.0 to 1.1.1 r=mkroening a=dependabot[bot]

Bumps [dsaltares/fetch-gh-release-asset](https://github.com/dsaltares/fetch-gh-release-asset) from 1.1.0 to 1.1.1.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/dsaltares/fetch-gh-release-asset/releases">dsaltares/fetch-gh-release-asset's releases</a>.</em></p>
<blockquote>
<h2>1.1.1</h2>
<h2>What's Changed</h2>
<ul>
<li>fix: 50 - actually default version to latest by <a href="https://github.com/dsaltares"><code>`@​dsaltares</code></a>` in <a href="https://redirect.github.com/dsaltares/fetch-gh-release-asset/pull/56">dsaltares/fetch-gh-release-asset#56</a></li>
<li>Bump json5 from 1.0.1 to 1.0.2 by <a href="https://github.com/dependabot"><code>`@​dependabot</code></a>` in <a href="https://redirect.github.com/dsaltares/fetch-gh-release-asset/pull/55">dsaltares/fetch-gh-release-asset#55</a></li>
</ul>
<h2>New Contributors</h2>
<ul>
<li><a href="https://github.com/dependabot"><code>`@​dependabot</code></a>` made their first contribution in <a href="https://redirect.github.com/dsaltares/fetch-gh-release-asset/pull/55">dsaltares/fetch-gh-release-asset#55</a></li>
</ul>
<p><strong>Full Changelog</strong>: <a href="https://github.com/dsaltares/fetch-gh-release-asset/compare/1.1.0...1.1.1">https://github.com/dsaltares/fetch-gh-release-asset/compare/1.1.0...1.1.1</a></p>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/dsaltares/fetch-gh-release-asset/commit/a40c8b4a0471f9ab81bdf73a010f74cc51476ad4"><code>a40c8b4</code></a> Bump json5 from 1.0.1 to 1.0.2 (<a href="https://redirect.github.com/dsaltares/fetch-gh-release-asset/issues/55">#55</a>)</li>
<li><a href="https://github.com/dsaltares/fetch-gh-release-asset/commit/5a71312bcb7a436e89a7dd26123cdbdd7b3df709"><code>5a71312</code></a> fix: 50 - actually default version to latest (<a href="https://redirect.github.com/dsaltares/fetch-gh-release-asset/issues/56">#56</a>)</li>
<li>See full diff in <a href="https://github.com/dsaltares/fetch-gh-release-asset/compare/1.1.0...1.1.1">compare view</a></li>
</ul>
</details>
<br />


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Bumps [bitflags](https://github.com/bitflags/bitflags) from 2.1.0 to 2.2.1.
- [Release notes](https://github.com/bitflags/bitflags/releases)
- [Changelog](https://github.com/bitflags/bitflags/blob/main/CHANGELOG.md)
- [Commits](https://github.com/bitflags/bitflags/compare/2.1.0...2.2.1

)

---
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  dependency-type: direct:production
  update-type: version-update:semver-minor
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Bumps [dsaltares/fetch-gh-release-asset](https://github.com/dsaltares/fetch-gh-release-asset) from 1.1.0 to 1.1.1.
- [Release notes](https://github.com/dsaltares/fetch-gh-release-asset/releases)
- [Commits](https://github.com/dsaltares/fetch-gh-release-asset/compare/1.1.0...1.1.1

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  dependency-type: direct:production
  update-type: version-update:semver-patch
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716: virtio-net: Replace AsSliceU8 trait with zerocopy::AsBytes. r=mkroening a=joannejchen

Changed VirtioNetHdr to derive from AsBytes instead of AsSliceU8 and changed related functions as necessary.


Co-authored-by: Joanne Chen <joannejc@cs.utexas.edu>

Changed VirtioNetHdr to derive from AsBytes instead of AsSliceU8 and
changed related functions as necessary. AsSliceU8 cannot be completely
removed yet because of lack of support for deriving AsBytes for
generics.

715: Replace use of internal syscalls r=mkroening a=nathanwhyte

Closes #676 

I found no internal uses of `__sys_realloc()` or `__sys_free()` anywhere.

I did find one reference to `__sys_shutdown()`:
https://github.com/hermitcore/libhermit-rs/blob/df7483de1b762c570f5d52e48fc396cdb739a12d/src/arch/x86_64/kernel/processor.rs#L832-L836

It doesn't redirect to any functions in [`lib.rs`](https://github.com/hermitcore/libhermit-rs/blob/master/src/lib.rs

) like `__sys_malloc()` does. Does it need to be replaced as well?

Co-authored-by: Nathan Whyte <nathanwhyte35@gmail.com>