Dear L4 hackers community, I want to implement a new syscall for getting/setting stored register values of a specific thread (identified by its cap). Preliminary note: I'm using the ARM architecture. Before implementing the syscall, I need to better understand the kernel-part of Fiasco.OC. Can you help me answer the following questions and point me to the source code regarding each question: * Where (in the source code) are threads preempted and their register state stored? * Where is the register state of a thread loaded to the CPU and the thread started (e.g. after a preempt)? * Where is the register state stored of each thread? * How can I introspect the stored thread register of a thread in the kernel debugger JDB? ** My thoughts: Is it K<kobj_ptr> with kobj_ptr of the thread and the 3 lines beginning with PC=...? e.g. " PC=010579cc USP=200ffdb0 smlatbeq r9, r0, r2, r5 [0] 00000003 000010c0 00218003 00000000 tsteq000r5, ip, rrx [8] 200ffdb0 200ffe40 01086ef0 200ffe98 [c] 200ffef8 010579cc fffffff8 20000010 " I also have another, short, off-topic question: * How can I introspect the capability space of a task inside the kernel debugger? Kind regards, Denis