Stefan Kalkowski 4e97a6511b hw: switch page-tables only when necessary ... * Instead of always re-load page-tables when a thread context is switched only do this when another user PD's thread is the next target, core-threads are always executed within the last PD's page-table set * remove the concept of the mode transition * instead map the exception vector once in bootstrap code into kernel's memory segment * when a new page directory is constructed for a user PD, copy over the top-level kernel segment entries on RISCV and X86, on ARM we use a designated page directory register for the kernel segment * transfer the current CPU id from bootstrap to core/kernel in a register to ease first stack address calculation * align cpu context member of threads and vms, because of x86 constraints regarding the stack-pointer loading * introduce Align_at template for members with alignment constraints * let the x86 hardware do part of the context saving in ISS, by passing the thread context into the TSS before leaving to user-land * use one exception vector for all ARM platforms including Arm_v6 Fix #2091		2017-10-19 13:31:18 +02:00
..
cpu	hw: switch page-tables only when necessary	2017-10-19 13:31:18 +02:00