sdc-g commented on PR #15985: URL: https://github.com/apache/nuttx/pull/15985#issuecomment-2735462706
Hi @chirping78 Sorry, one more discussion: while level-2 and above interrupt, PS.EXCM also set to 1. So if context switching happens, there is also double exception if window ratation instruction is executed. The sequence like: threadA PS.EXCM is 0 -> PS.EXCM set to 1 while level-2 interrupt -> context switching to threadB -> level-2 interrupt and resume threadA with PS.EXCM=1, then double exception Please refer to "xtensa Instruction Set Architecture (ISA) Reference Manual" ``` The taking of an exception under the Exception Option has the following semantics: procedure Exception(cause) if (PS.EXCM & NDEPC=1) then DEPC ← PC nextPC ← DoubleExceptionVector elseif PS.EXCM then EPC[1] ← PC nextPC ← DoubleExceptionVector elseif PS.UM then EPC[1] ← PC nextPC ← UserExceptionVector else EPC[1] ← PC nextPC ← KernelExceptionVector endif EXCCAUSE ← cause PS.EXCM ← 1 endprocedure Exception ``` Is it possible and correct understanding? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
