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<a href="https://gitlab.rtems.org/skdatar">Shaunak Datar</a> created an issue: <a href="https://gitlab.rtems.org/rtems/programs/gsoc/-/issues/89">#89</a>
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<h2 id="user-content-background" dir="auto" style="margin-top: 0; margin-bottom: 10px;" align="initial">Background<a href="#background" aria-label="Link to heading 'Background'" data-heading-content="Background" class="anchor" style="margin-top: 0;"></a>
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<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial">The Raspberry Pi BSP support has improved over the years. Last year the BSP received Mailbox and DMA support. The motivation for adding their support was to ultimately add support for SD support pending since 2024.
The recent mailbox addition also enabled us to add support for framebuffer. Along with framebuffer and sd card support PCI support exists in freebsd upstream which could be added to the BSP.</p>
<h2 id="user-content-approach" dir="auto" style="margin-top: 20px; margin-bottom: 10px;" align="initial">Approach:<a href="#approach" aria-label="Link to heading 'Approach:'" data-heading-content="Approach:" class="anchor" style="margin-top: 0;"></a>
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<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial"><strong style="font-weight: 600; margin-top: 0;">Framebuffer support:</strong> The mailbox support enables framebuffer initialization via the VideoCore mailbox property interface(Channel 8). Refer this link for details on property interface and framebuffer: <a href="https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface" rel="nofollow noreferrer noopener" target="_blank">Github Wiki</a></p>
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial"><strong style="font-weight: 600; margin-top: 0;">SD card support:</strong> The sdhci driver has been pending since 2024. With the support for mailbox and DMA now added the work remaining is the SDHCI glue layer for the Rasperry Pi 4b BSP. The upstream freebsd driver at sys/arm/broadcom/bcm2835/bcm2835_sdhci.c. This needs to be imported into libbsd and adapted for RTEMS. Refer to the Chapter 5 in the BCM2835 arm peripherals manual and existing DMA and Mailbox support.</p>
<p dir="auto" style="color: #3a383f; margin: 0 0 1rem;" align="initial"><strong style="font-weight: 600; margin-top: 0;">PCIe Support:</strong> Freebsd has upstream support for PCI at sys/arm/broadcom/bcm2835/bcm2838_pci.c. This needs to be imported to RTEMS libbsd. We would use the freebsd-to-rtems.py script and import the driver.</p>
<h2 id="user-content-knowledgeskills" dir="auto" style="margin-top: 20px; margin-bottom: 10px;" align="initial">Knowledge/Skills<a href="#knowledgeskills" aria-label="Link to heading 'Knowledge/Skills'" data-heading-content="Knowledge/Skills" class="anchor" style="margin-top: 0;"></a>
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<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;">C, assembly</li>
<li style="line-height: 1.6em; margin-left: 25px; padding-left: 3px;">Hardware-level debugging</li>
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<h2 id="user-content-possible-mentors" dir="auto" style="margin-top: 20px; margin-bottom: 10px;" align="initial">Possible Mentors<a href="#possible-mentors" aria-label="Link to heading 'Possible Mentors'" data-heading-content="Possible Mentors" class="anchor" style="margin-top: 0;"></a>
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<p dir="auto" style="color: #3a383f; margin: 0;" align="initial"><a href="https://gitlab.rtems.org/opticron" title="Kinsey Moore" class="gfm gfm-project_member js-user-link" data-user="4" data-original="@opticron" 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;">@opticron</a></p>
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—
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<a href="https://gitlab.rtems.org/rtems/programs/gsoc/-/issues/89">View it on GitLab</a>.
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