x86 Assembly Language Reference Manual

3.33 Operating System Support Instructions

The operating system support instructions provide functionality for process management, performance monitoring, debugging, and other systems tasks.

Table 73  Operating System Support Instructions

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes arpl ARPL adjust requested privilege level clts CLTS clear the task-switched flag hlt HLT halt processor invd INVD invalidate cache, no writeback invlpg INVLPG invalidate TLB entry lar LAR load access rights larq valid only under –m64 lgdt LGDT load global descriptor table (GDT) register lidt LIDT load interrupt descriptor table (IDT) register lldt LLDT load local descriptor table (LDT) register lmsw LMSW load machine status word lock LOCK lock bus lsl LSL load segment limit lslq valid only under –m64 ltr LTR load task register rdmsr RDMSR read model-specific register rdpmc RDPMC read performance monitoring counters rdtsc RDTSC read time stamp counter rsm RSM return from system management mode (SMM) sgdt SGDT store global descriptor table (GDT) register sidt SIDT store interrupt descriptor table (IDT) register sldt SLDT store local descriptor table (LDT) register sldtq valid only under –m64 smsw SMSW store machine status word smswq valid only under –m64 str STR store task register strq valid only under –m64 sysenter SYSENTER fast system call, transfers to a flat protected model kernel at CPL=0 sysexit SYSEXIT fast system call, transfers to a flat protected mode kernal at CPL=3 verr VERR verify segment for reading verw VERW verify segment for writing wbinvd WBINVD invalidate cache, with writeback wrmsr WRMSR write model-specific register