src/system/libroot/os/arch/x86_64/time.cpp

   1 /*
   2  * Copyright 2004, Axel Dörfler, axeld@pinc-software.de.
   3  * Copyright 2012, Alex Smith, alex@alex-smith.me.uk.
   4  * Distributed under the terms of the MIT License.
   5  */
   6
   7
   8 #include <libroot_private.h>
   9 #include <real_time_data.h>
  10 #include <arch_cpu.h>
  11
  12
  13 void
  14 __arch_init_time(real_time_data* data, bool setDefaults)
  15 {
  16         uint32 conversionFactor;
  17         uint64 conversionFactorNsecs;
  18
  19         if (setDefaults) {
  20                 data->arch_data.system_time_offset = 0;
  21                 data->arch_data.system_time_conversion_factor = 100000;
  22         }
  23
  24         // TODO: this should only store a pointer to that value
  25         // When resolving this TODO, also resolve the one in the Jamfile.
  26
  27         conversionFactor = data->arch_data.system_time_conversion_factor;
  28         conversionFactorNsecs = (uint64)conversionFactor * 1000;
  29
  30         // The x86_64 system_time() implementation uses 64-bit multiplication and
  31         // therefore shifting is not necessary for low frequencies (it's also not
  32         // too likely that there'll be any x86_64 CPUs clocked under 1GHz).
  33         __x86_setup_system_time((uint64)conversionFactor << 32,
  34                 conversionFactorNsecs);
  35 }
  36
  37
  38 bigtime_t
  39 __arch_get_system_time_offset(struct real_time_data *data)
  40 {
  41         //we don't use atomic_get64 because memory is read-only, maybe find another way to lock
  42         return data->arch_data.system_time_offset;
  43 }
  44