{"id":59481,"date":"2023-09-20T09:44:14","date_gmt":"2023-09-20T13:44:14","guid":{"rendered":"http:\/\/pappp.net\/?guid=d305e6983a2fbaf571bb33bd11b4796c"},"modified":"2023-09-20T09:44:14","modified_gmt":"2023-09-20T13:44:14","slug":"running-palmos-on-a-raspberry-pi-rp2040-raspberrypi-rp2040-dmitrygr-raspberry_pi","status":"publish","type":"post","link":"https:\/\/pappp.net\/?p=59481","title":{"rendered":"Running PalmOS on a Raspberry Pi RP2040 #RaspberryPi #RP2040 @dmitrygr @Raspberry_Pi"},"content":{"rendered":"<p class=\"syndicated-attribution\">Source: <a href=\"https:\/\/blog.adafruit.com\/2023\/09\/20\/running-palmos-on-a-raspberry-pi-rp2040-raspberrypi-rp2040-dmitrygr-raspberry_pi\/\">adafruit industries blog<\/a><\/p>\n<div style=\"background-color : #fff7d5;\n\t\t\tborder-width : 1px; padding : 5px; border-style : dashed; border-color : #e7d796;margin-bottom : 1em; color : #9a8c59;\">Article note: Motherfucker wrote a bare-metal kernel for Cortex-M3\/M4 (and now M0) class parts, an ARM-on-Thumb JIT, and all the support infrastructure to host PalmOS5 on modern Cortex-M micocontrollers. \nHoly shit.<\/div><p><img decoding=\"async\" src=\"https:\/\/cdn-blog.adafruit.com\/uploads\/2023\/09\/x-7.gif\" alt=\"\" referrerpolicy=\"no-referrer\" loading=\"lazy\"\/><\/p><p>Dmitry Grinberg had demonstrated a Raspberry Pi RP2040 microcontroller running unmodified PalmOS 5.2.8 (showing off world&rsquo;s only ARM-to-thumb1 just in time (JIT) compiler).<\/p><blockquote><p>How little RAM\/CPU does PalmOS 5 really require? Since rePalm had support (at least in theory) for Cortex-M0, I wanted to try on real hardware, as previously the support was tested on CortexEmu only. There does happen to be one Cortex-M0 chip out there with enough ram &ndash; the RP2040 &ndash; the chip in the $4&nbsp;<a href=\"https:\/\/www.adafruit.com\/product\/4883\"  rel=\"noopener noreferrer\">Raspberry Pi Pico<\/a>. I then sought out a display with a touchscreen that could be easily bought. There were actually not that many options, but&nbsp;<a href=\"https:\/\/www.waveshare.com\/pico-restouch-lcd-2.8.htm\"  rel=\"noopener noreferrer\">this one<\/a>&nbsp;seemed like a good fit. It turned out, after some investigation, that driving it properly and quickly will not be at all easy. RP2040&rsquo;s special sauce &ndash; the PIO &ndash; to the rescue!<\/p><\/blockquote><p>Dmitry documents the extensive history and architecture of Palm devices and their operating system, from Motorola 68000 versions to the switch to Arm devices. A masterclass in both Palm and reverse engineering.<\/p><p>See <a href=\"http:\/\/dmitry.gr\/?r=05.Projects&amp;proj=27.%20rePalm#_TOC_0734fd58b98b17e23027547eec1258f5\"  rel=\"noopener noreferrer\">this post<\/a> for all the details. Via <a href=\"https:\/\/twitter.com\/dmitrygr\/status\/1704350983877198013\"  rel=\"noopener noreferrer\">X<\/a> (formerly Twitter).<\/p><div><\/div>\n<span><!-- --><\/span>","protected":false},"excerpt":{"rendered":"<p>Dmitry Grinberg had demonstrated a Raspberry Pi RP2040 microcontroller running unmodified PalmOS 5.2&#8230;<\/p>\n<p> <a href=\"https:\/\/pappp.net\/?p=59481\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[226],"tags":[],"class_list":["post-59481","post","type-post","status-publish","format-standard","hentry","category-news-2"],"_links":{"self":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts\/59481","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=59481"}],"version-history":[{"count":0,"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts\/59481\/revisions"}],"wp:attachment":[{"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=59481"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=59481"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=59481"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}