Stefan Kerkmann 9a64f5c17c Force machine mode on interrupt exit for context switches ... The first attempt to solve illegal instruction expections was made in commit b875108cd0 It seemed as this "fixed" the issue, but merely added delays in the code which prevented the error to appear in lucky circumstances. Interesting that this code worked in the first place. Root cause for the expections where write attempts to mstatus in user privilege mode which raised the illegal instruction exception which is in spec with the risc-v privileged isa and documented in the bumbleebee core architecture manual by nucleisys. The solution is to never enter user mode by forceing mcause.mpp to 0x3 before calling mret when exiting the interrupt handler for context switching.		2021-04-17 19:36:44 +02:00
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ext	Add Nucleisys NMSIS sources	2021-04-06 13:38:21 +02:00
ports	Force machine mode on interrupt exit for context switches	2021-04-17 19:36:44 +02:00
startup	Add myself to copyright notes :-)	2021-04-06 13:38:23 +02:00