<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html lang="en" style="--code-editor-font: var(--default-mono-font, "GitLab Mono"), JetBrains Mono, Menlo, DejaVu Sans Mono, Liberation Mono, Consolas, Ubuntu Mono, Courier New, andale mono, lucida console, monospace;">
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
<title>
GitLab
</title>
<style data-premailer="ignore" type="text/css">
a { color: #1068bf; }
</style>
<style>img {
max-width: 100%; height: auto;
}
body {
font-size: .875rem;
}
body {
-webkit-text-shadow: rgba(255,255,255,.01) 0 0 1px;
}
body {
font-family: "GitLab Sans",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans",Ubuntu,Cantarell,"Helvetica Neue",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji"; font-size: inherit;
}
</style>
</head>
<body style="font-size: inherit; -webkit-text-shadow: rgba(255,255,255,.01) 0 0 1px; font-family: "GitLab Sans",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans",Ubuntu,Cantarell,"Helvetica Neue",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";">
<div class="content">
<p style="color: #777777;">
<a href="https://gitlab.rtems.org/mithileshm">MITHILESH MATTAPALLI</a>
<a href="https://gitlab.rtems.org/rtems/rtos/rtems/-/issues/5440#note_142829">commented</a>:
</p>
<div class="md" style="position: relative; z-index: 1; color: #3a383f; word-wrap: break-word;">
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial">I have been analyzing this issue scope for my <strong style="font-weight: 600; margin-top: 0;">GSoC 2026</strong> proposal.</p>
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial">Following up on the queue initialization race conditions I investigated in <strong style="font-weight: 600; margin-top: 0;"><a href="https://gitlab.rtems.org/rtems/rtos/rtems/-/merge_requests/1059" title="cpukit/dev/can: Check task start status in queue init (CID 1642607)" class="gfm gfm-merge_request" data-original="!1059" data-link="false" data-link-reference="false" data-merge-request="2162" data-project="26" data-project-path="rtems/rtos/rtems" data-iid="1059" data-container="body" data-placement="top" data-reference-type="merge_request" style="margin-top: 0;">!1059</a></strong>, I wanted to share my findings on the current state of the stack and validate my proposed architecture.</p>
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial"><strong style="font-weight: 600; margin-top: 0;">Observations from Code Study:</strong></p>
<ol dir="auto" style="text-align: initial; margin: 0 0 1rem; padding: 0;">
<li style="margin-top: 0; line-height: 1.6em; margin-left: 25px; padding-left: 3px;">
<strong style="font-weight: 600; margin-top: 0;">Testing Gap:</strong> The current regression testing relies heavily on physical hardware, which limits our ability to catch race conditions in CI.</li>
<li style="line-height: 1.6em; margin-left: 25px; padding-left: 3px;">
<strong style="font-weight: 600; margin-top: 0;">Controller Support:</strong> As <a href="https://gitlab.rtems.org/ppisa" title="Pavel Pisa" class="gfm gfm-project_member js-user-link" data-user="20" data-original="@ppisa" data-container="body" data-placement="top" data-reference-type="user" style="color: #284779; background-color: #cbe2f9; border-radius: .25rem; padding: 0 2px;">@ppisa</a> noted, QEMU has mainline support for <strong style="font-weight: 600;">SJA1000</strong> and <strong style="font-weight: 600;">CTU CAN FD</strong>, but these are primarily exposed as PCI devices. The RTEMS Tester currently lacks a standard BSP configuration to utilize these for automated testing.</li>
<li style="line-height: 1.6em; margin-left: 25px; padding-left: 3px;">
<strong style="font-weight: 600; margin-top: 0;">Core Fragility:</strong> The <code style="font-size: 90%; color: #18171d; word-wrap: break-word; background-color: #ececef; border-radius: .25rem; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; font-variant-ligatures: none; white-space: pre-wrap; overflow-wrap: break-word; word-break: keep-all; padding: 0.125rem 0.25rem;">can_queue_create</code> path lacks robust error handling for kernel object creation failures, leaving the stack in an undefined state during initialization faults.</li>
</ol>
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial"><strong style="font-weight: 600; margin-top: 0;">Understanding & Proposed Plan:</strong> My proposal will focus on <strong style="font-weight: 600;">'Hardening & Virtualization'</strong> to address both the "New Controller" and "Rigorous Test Suite" requirements:</p>
<ul dir="auto" style="text-align: initial; list-style-type: disc; margin: 0 0 1rem; padding: 0;">
<li style="margin-top: 0; line-height: 1.6em; margin-left: 25px; padding-left: 3px;">
<strong style="font-weight: 600; margin-top: 0;">Virtual Lab (The "Rigorous Test Suite"):</strong> I will integrate the <strong style="font-weight: 600;">CTU CAN FD</strong> PCI support into the RTEMS Tester. This involves configuring a generic BSP (likely <code style="font-size: 90%; color: #18171d; word-wrap: break-word; background-color: #ececef; border-radius: .25rem; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; font-variant-ligatures: none; white-space: pre-wrap; overflow-wrap: break-word; word-break: keep-all; padding: 0.125rem 0.25rem;">pc386</code> or <code style="font-size: 90%; color: #18171d; word-wrap: break-word; background-color: #ececef; border-radius: .25rem; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; font-variant-ligatures: none; white-space: pre-wrap; overflow-wrap: break-word; word-break: keep-all; padding: 0.125rem 0.25rem;">pc686</code>) to enumerate the QEMU PCI bus and load the driver, enabling a purely software-based regression suite.</li>
<li style="line-height: 1.6em; margin-left: 25px; padding-left: 3px;">
<strong style="font-weight: 600; margin-top: 0;">Core Hardening:</strong> I will refactor the <code style="font-size: 90%; color: #18171d; word-wrap: break-word; background-color: #ececef; border-radius: .25rem; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; font-variant-ligatures: none; white-space: pre-wrap; overflow-wrap: break-word; word-break: keep-all; padding: 0.125rem 0.25rem;">can-queue</code> layer to enforce atomic state transitions, ensuring that resources are cleanly rolled back if initialization fails (addressing the root cause of <a href="https://gitlab.rtems.org/rtems/rtos/rtems/-/merge_requests/1059" title="cpukit/dev/can: Check task start status in queue init (CID 1642607)" class="gfm gfm-merge_request" data-original="!1059" data-link="false" data-link-reference="false" data-merge-request="2162" data-project="26" data-project-path="rtems/rtos/rtems" data-iid="1059" data-container="body" data-placement="top" data-reference-type="merge_request">!1059</a>).</li>
</ul>
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial"><strong style="font-weight: 600; margin-top: 0;">Question for Mentors (<a href="https://gitlab.rtems.org/ppisa" title="Pavel Pisa" class="gfm gfm-project_member js-user-link" data-user="20" data-original="@ppisa" data-container="body" data-placement="top" data-reference-type="user" style="color: #284779; background-color: #cbe2f9; border-radius: .25rem; margin-top: 0; padding: 0 2px;">@ppisa</a>):</strong> Regarding the QEMU integration, would you prefer the test suite target a generic PCI-capable BSP (like <code style="font-size: 90%; color: #18171d; word-wrap: break-word; background-color: #ececef; border-radius: .25rem; font-weight: inherit; overflow-wrap: break-word; white-space: break-spaces; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; font-variant-ligatures: none; word-break: keep-all; padding: 0.125rem 0.25rem;">pc386</code>) to leverage the existing QEMU PCI support, or should we aim to extend a specific embedded BSP (like <code style="font-size: 90%; color: #18171d; word-wrap: break-word; background-color: #ececef; border-radius: .25rem; font-weight: inherit; overflow-wrap: break-word; white-space: break-spaces; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; font-variant-ligatures: none; word-break: keep-all; padding: 0.125rem 0.25rem;">xilinx_zynq</code>) to support these virtual controllers?</p>
<p dir="auto" style="color: #3a383f; margin: 0;" align="initial">My assumption is that the generic PCI approach is more stable for CI purposes. I am drafting the detailed proposal based on this architecture.</p>
</div>
</div>
<div class="footer" style="margin-top: 10px;">
<p style="font-size: small; color: #626168;">
—
<br>
<a href="https://gitlab.rtems.org/rtems/rtos/rtems/-/issues/5440#note_142829">View it on GitLab</a>.
<br>
You're receiving this email because of your account on <a target="_blank" rel="noopener noreferrer" href="https://gitlab.rtems.org">gitlab.rtems.org</a>. <a href="https://gitlab.rtems.org/-/sent_notifications/2-121e8zsp1zxi7ubmls91kaqlp/unsubscribe" target="_blank" rel="noopener noreferrer">Unsubscribe</a> from this thread · <a href="https://gitlab.rtems.org/-/profile/notifications" target="_blank" rel="noopener noreferrer" class="mng-notif-link">Manage all notifications</a> · <a href="https://gitlab.rtems.org/help" target="_blank" rel="noopener noreferrer" class="help-link">Help</a>
<span style="color: transparent; font-size: 0; display: none; overflow: hidden; opacity: 0; width: 0; height: 0; max-width: 0; max-height: 0;">
Notification message regarding https://gitlab.rtems.org/rtems/rtos/rtems/-/issues/5440#note_142829 at 1771272414
</span>
<script type="application/ld+json">{"@context":"http://schema.org","@type":"EmailMessage","action":{"@type":"ViewAction","name":"View Issue","url":"https://gitlab.rtems.org/rtems/rtos/rtems/-/issues/5440#note_142829"}}</script>
</p>
</div>
</body>
</html>