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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/"><channel><title>Jason69s's Groups Activities</title><link>https://community.arm.com/members/jason69s</link><description>Recent activity for people in Jason69s's group</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>sp register minus fault in stp instruction</title><link>https://community.arm.com/developer/ip-products/processors/f/cortex-a-forum/47687/sp-register-minus-fault-in-stp-instruction</link><pubDate>Tue, 22 Sep 2020 08:16:50 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:f2bc6ddf-50c2-48da-ab20-45bacc0f2312</guid><dc:creator>Jason69s</dc:creator><description>&lt;p&gt;&lt;strong&gt;summary:&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;sp (0000000012108d90) - 48 = 0x&lt;span style="color:#ff0000;"&gt;4&lt;/span&gt;000000012108d60 when exec stp instruction (62 bit become 1). Could anyone help to explain why this happen? Thanks.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;the details in below:&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;We get a level 0 translation fault when exec the instruction below:&lt;/p&gt;
&lt;p&gt;```&lt;br /&gt; 10016e74: a9bd7bfd stp x29, x30, [sp, #-48]!&lt;br /&gt;```&lt;/p&gt;
&lt;p&gt;we dump all the register in the exception handler:&lt;/p&gt;
&lt;p&gt;```&lt;br /&gt;ESR=0x0000000096000044 EC=0x25 IL=0x1 ISS=0x44&lt;br /&gt;ELR=0x0000000010016e74 FAR=0x4000000012108d60 HPFAR=0x0000000009780a30&lt;/p&gt;
&lt;p&gt;pc : [&amp;lt;0000000010016e74&amp;gt;] lr : [&amp;lt;0000000010008f5c&amp;gt;] pstate: 800003c9&lt;br /&gt;sp : 0000000012108d90&lt;br /&gt;x29: 0000000012108d90 x28: 00000000120d1aa8 &lt;br /&gt;x27: 0000000000000000 x26: 00000000000003c0 &lt;br /&gt;x25: 0000000000000000 x24: 00000000158050c8 &lt;br /&gt;x23: 0000000012108e90 x22: 00000002564eccaf &lt;br /&gt;x21: 0000000005725000 x20: 00000000120d1aa8 &lt;br /&gt;x19: 00000000120d4dd8 x18: 0000000000000000 &lt;br /&gt;x17: 0000000000000000 x16: 0000000000000000 &lt;br /&gt;x15: 0000000000000000 x14: 0000000012208fc0 &lt;br /&gt;x13: ffff00000808592c x12: ffff0000095cbf10 &lt;br /&gt;x11: 0000000000000000 x10: 0000000000000000 &lt;br /&gt;x9 : 0000000000000000 x8 : 00000000600001c5 &lt;br /&gt;x7 : ffff00000809f5c8 x6 : 0000000012108fa0 &lt;br /&gt;x5 : 0000000000000020 x4 : 0000000000000000 &lt;br /&gt;x3 : 0000000000000010 x2 : ffffffffffffffd0 &lt;br /&gt;x1 : 0000000012207100 x0 : 00000000120d4dd8 &lt;br /&gt;```&lt;/p&gt;
&lt;p&gt;From EC and ISS we know this is a level 0 translation fault.&lt;/p&gt;
&lt;p&gt;sp is 0000000012108d90, but FAR is 0x4000000012108d60, which means 0x0000000012108d90 - 48 = 0x4000000012108d60. The 62 bit become 1.&lt;/p&gt;
&lt;p&gt;Could anyone help to explain why this happen?&lt;/p&gt;
&lt;p&gt;&lt;br /&gt;Thanks.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>Ask A Question I</title><link>https://community.arm.com/achievements/460ac7df-7ccc-4c42-a204-9e05eef3be09</link><pubDate>Tue, 22 Sep 2020 05:35:16 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:db90633f-e790-4a46-900d-2a061fe52d06</guid><dc:creator /><description>Ask a question in a forum.</description></item></channel></rss>