IA-PC HPET IA-PC HPET (High Precision Event Timer) is a specification which was jointly developed by Intel and Microsoft in the early part of this decade.. (High Precision Event Timer) je špecifikácia, ktorá bola spoločne vyvinutý spoločnosťou Intel a Microsoft na začiatku tohto desaťročia .. The latest version is dated October 2004. Posledná verzia je z októbra 2004. It's stated purpose is to Je to uvádza cieľom je
initially supplement and eventually replace the legacy 8254 Programmable Interval Timer and the Real Time Clock Periodic Interrupt generation functions that are currently used as the 'de-facto' timer hardware for IA-PCs. spočiatku doplniť a nakoniec nahradia staršie 8254 Programovateľný Interval Timer a Real Time Clock periodickej prerušenia výroby funkcií, ktoré sú v súčasnosti používa ako 'de-facto' časovač hardvéru pre architektúru IA-PC.
The HPET HPET architecture defines a set of timers that can be used by the operating system. architektúra definuje sadu časovačov, ktoré možno použiť v operačnom systéme. A timer block is a combination of a single counter and up to 32 comparators and match registers. Časovač blok je kombináciou jedného pultu a až 32 komparátory a zápas registrov. The comparator compares the contents of the match register against the value of a free running monotonic up-counter. Komparátor porovnáva obsah registra stretnutie proti hodnote free running monotónna up-pult. When the output of the up-counter equals the value in the match register an interrupt is generated. Pri výstupe do counter-rovná hodnote v zápase registri prerušenie je generované. Each of the comparators can output an interrupt. Každá zo porovnávaných môže výstup prerušiť. A maximum of 8 timer blocks are supported for a total of 256 timers. Maximálne 8 hodín blokov sú podporované pre celkom 256 časovačov. Each timer block can have different clocking attributes. Každý časovač blok môže mať rôzne atribúty stopovanie. Specific implementations may include only a subset of these timers. Konkrétne implementácia môže obsahovať iba podmnožinu týchto časovačov. A minimum of three timers is required. Najmenej tri časovača je potrebné.
The specification contains the following block diagram of the HPET architecture. Špecifikácia obsahuje nasledujúce bloková schéma architektúry HPET.
Some of the timers may be enabled to generate a periodic interrupt. Niektoré z časovače môžu byť umožnené generovať periodické prerušenia. If a timer is set to be periodic, its period is added to the match register each time a match occurs, thus computing the next time for this timer to generate an interrupt.. Je-li časovač je nastavený na pravidelné, je jeho doba pridaný do zápasu registrovať zakaždým, keď dôjde k zápasu, tak výpočtovej nabudúce pre tento časovač pre generovanie prerušenia .. An up-counter is usually 64 bits wide but 32-bit implementations are permitted by the specification and 64-bit up-counters can also be driven in 32-bit mode. Counter-up je zvyčajne 64 bitov široké, ale 32-bitové implementácie sú pripúšťajú špecifikácií a 64-bit up-čítača môže byť riadené v 32-bitovom režime. Up-counters run at a minimum of 10 MHz. Up-pulty bežať na minimálne 10 MHz. which is much faster than the older čo je oveľa rýchlejšie ako staršie RTC RTC (Real Time Clock) and can thus produce periodic interrupts at a much higher resolution. (Real Time Clock), a tak môžu produkovať pravidelne prerušuje na oveľa vyššie rozlíšenie. The registers associated with these timers are mapped to memory space. Registre spojené s týmito časovača sa mapovali do pamäťového priestoru.
The BIOS uses BIOS používa ACPI ACPI ( Advanced Configuration and Power Interface) functionality to inform the operating system of the location of the HPET memory-mapped register space. (Advanced Configuration and Power Interface) funkcie informovať operačný systém umiestnenie pamäte HPET-mapoval register priestoru. Here is an example of a disassembled ACPI HPET table from an Intel DX48BT2 (AKA BoneTrail) motherboard. Tu je príklad rozloženom ACPI tabuľky HPET od Intel DX48BT2 (AKA Bonetrail), základná doska.
$ cat /sys/firmware/acpi/tables/HPET > /var/tmp/hpet.out $ iasl -d /var/tmp/hpet.out $ cat /var/tmp/hpet.dsl /* * Intel ACPI Component Architecture * AML Disassembler version 20090123 * * Disassembly of /var/tmp/hpet.out, Sun Jul 5 19:34:47 2009 * * ACPI Data Table [HPET] * * Format: [HexOffset DecimalOffset ByteLength] FieldName : FieldValue */ [000h 000 4] Signature : "HPET" /* High Precision Event Timer table */ [004h 004 4] Table Length : 00000038 [008h 008 1] Revision : 01 [009h 009 1] Checksum : CE [00Ah 010 6] Oem ID : "INTEL " [010h 016 8] Oem Table ID : "DX48BT2 " [018h 024 4] Oem Revision : 0000076E [01Ch 028 4] Asl Compiler ID : "MSFT" [020h 032 4] Asl Compiler Revision : 01000013 [024h 036 4] Hardware Block ID : 8086A301 [028h 040 12] Timer Block Register :[028h 040 1] Space ID : 00 (SystemMemory) [029h 041 1] Bit Width : 00 [02Ah 042 1] Bit Offset : 00 [02Bh 043 1] Access Width : 00 [02Ch 044 8] Address : 00000000FED00000 [034h 052 1] Sequence Number : 00 [035h 053 2] Minimum Clock Ticks : 0001 [037h 055 1] Flags (decoded below) : 00 Page Protect : 0 4K Page Protect : 0 64K Page Protect : 0 Raw Table Data 0000: 48 50 45 54 38 00 00 00 01 CE 49 4E 54 45 4C 20 HPET8.....INTEL 0010: 44 58 34 38 42 54 32 20 6E 07 00 00 4D 53 46 54 DX48BT2 n...MSFT 0020: 13 00 00 01 01 A3 86 80 00 00 00 00 00 00 D0 FE ................ 0030: 00 00 00 00 00 01 00 00 ........ $
See page 30 of the HPET v1.0a specification for a detailed breakdown of the individual bits in the Event Time Block (called Hardware Block by the AML disassember). Pozri stranu 30 špecifikácie 1.0a HPET pre podrobný rozpis jednotlivých bitov v prípade času Blok (tzv. Hardware bloku proti praniu špinavých peňazí disassember). Note that only one Event Timer Block need be described in the HPET table in order to bootstrap an operating system. Všimnite si, že len jedna udalosť Timer Blok musí byť opísané v tabuľke HPET, aby sa štartovacie operačného systému. This is the case here. To je prípad tu. For non-legacy platforms, the Event Timer Block described in the HPET is the one that provides functionality to replace the 8254/RTC Periodic Interrupt Logic. Pre ne-legacy platformy, udalosti Timer bloku je popísané v HPET je ten, ktorý poskytuje funkčnosť nahradiť 8254/RTC periodickej prerušenia Logic.
Other Event Time Blocks are described in the ACPI namespace. Ostatné udalosti Čas Bloky sú opísané v odbore názvov ACPI. Here is the relevant section from the disassembled ACPI DSDT table. Tu je relevantná časť z rozobratých ACPI DSDT tabuľku.
Device (HPET)
{
Name (_HID, EisaId ("PNP0103"))
Name (_CRS, ResourceTemplate ()
{
Memory32Fixed (ReadOnly,
0xFED00000, // Address Base
0x00004000, // Address Length
)
})
Method (_STA, 0, NotSerialized)
{
If (HPEE)
{
Return (0x0F)
}
Else
{
Return (Zero)
}
}
}
Note the assigned PNPID ( PNP0103 ) for the HPET. Poznámka: pridelené PNPID (PNP0103) pre HPET. Because no _UID is specified it means that there are no other HPET timer blocks. Keďže žiadny _UID je uvedené to znamená, že neexistujú žiadne ďalšie bloky HPET časovač.
Here is a list of the HPET-related messages outputted when this particular motherboard is booted up under Fedora 11. Tu je zoznam HPET-súvisiace outputted správy, ak je to mimoriadne doska topánka autobus pod Fedora 11.
$ dmesg | grep -i HPET ACPI: HPET CFBF2000, 0038 (r1 INTEL DX48BT2 76E MSFT 1000013) ACPI: HPET id: 0x8086a301 base: 0xfed00000 hpet clockevent registered HPET: 4 timers in total, 0 timers will be used for per-cpu timer hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0 hpet0: 4 comparators, 64-bit 14.318180 MHz counter rtc0: alarms up to one month, 114 bytes nvram, hpet irqs $
The first line is outputted when the ACPI HPET table is read. Prvý riadok je outputted po prečítaní ACPI HPET tabuľky. The second line is outputted when the ACPI HPET table is mapped into memory by …/arch/x86/kernel/acpi/boot.c . Druhý riadok je outputted keď je ACPI HPET tabuľky mapovaná do pamäti ... / arch/x86/kernel/acpi/boot.c. The next line is outputted when the HPET legacy interrupts are started and HPET is registered as the global clock. Ďalšia linka je outputted keď sa preruší HPET dedičstva začalo a HPET je registrovaný ako svetové hodiny. The following line is outputted when the kernel checks to ensure that at least one timer is reserved for userspace ( /dev/hpet .) The next two lines of output comes from the HPET device driver ( …/drivers/char/hpet.c .) It shows that 2 timers have allocated interrupts and two do not.. Nasledujúci riadok outputted keď jadro kontroly, aby zabezpečili, že aspoň jeden časovač je vyhradené pre užívateľský priestor (/ dev / HPET.) Ďalšie dva riadky výstupu pochádza z ovládača zariadenia HPET (... / drivers / char / hpet.c. ) Z toho vyplýva, že 2 časovača boli pridelené preruší a dvaja nie ..
Here is the relevant part of the output from /proc/time_list as it relates to HPET: Tu je odkaz na príslušnú časť výstupu z / proc / time_list sa týka HPET:
Tick Device: mode: 1 Broadcast device Clock Event Device: hpet max_delta_ns: 149983005959 min_delta_ns: 5000 mult: 61496114 shift: 32 mode: 3 next_event: 9223372036854775807 nsecs set_next_event: hpet_legacy_next_event set_mode: hpet_legacy_set_mode event_handler: tick_handle_oneshot_broadcast tick_broadcast_mask: 00000000 tick_broadcast_oneshot_mask: 00000000
Here is the output from /proc/sys/dev/hpet and /proc/driver/rtc : Tu je výstup z / proc / sys / dev / HPET a / proc / driver / rtc:
$ cat /proc/sys/dev/hpet/max-user-freq 64 $ cat /proc/driver/rtc rtc_time : 06:34:31 rtc_date : 2009-07-06 alrm_time : **:24:40 alrm_date : ****-**-** alarm_IRQ : no alrm_pending : no 24hr : yes periodic_IRQ : no update_IRQ : no HPET_emulated : yes DST_enable : no periodic_freq : 1024 batt_status : okay
The HPET driver ( /dev/hpet ) has a similar API to the Real Time Clock driver. HPET driver (/ dev / HPET) má podobné API pre Real Time Clock driver. It is a character device which can support any number of HPET devices. Jedná sa o znakové zariadenia, ktoré môžu podporiť ľubovoľnom počte zariadení HPET. The kernel API has three interfaces exported from the driver: Jadrá API rozhranie má tri vyvážené od vodiča:
hpet_register( struct hpet_task *tp, int periodic ) hpet_unregister( struct hpet_task *tp ) hpet_control( struct hpet_task *tp, unsigned int cmd, unsigned long arg )
The userspace interface to HPET is defined in the header /usr/include/linux/hpet.h . Rozhranie pre užívateľský priestor HPET je definovaný v hlavičke / usr / include / linux / hpet.h. The current set of supported operations is: Súčasný súbor podporovaných aktivít je:
#define HPET_IE_ON _IO('h', 0x01) /* interrupt on */
#define HPET_IE_OFF _IO('h', 0x02) /* interrupt off */
#define HPET_INFO _IOR('h', 0x03, struct hpet_info) /* get information */
#define HPET_EPI _IO('h', 0x04) /* enable periodic */
#define HPET_DPI _IO('h', 0x05) /* disable periodic */
#define HPET_IRQFREQ _IOW('h', 0x6, unsigned long) /* set frequency */
The following example shows how to use the published interface to access a HPET and call a simple periodic signal handler hpet_alarm between 2 and 99 times a second. Nasledujúci príklad ukazuje, ako používať uverejnené rozhranie pre prístup k HPET a volať jednoduché periodické signálu hpet_alarm medzi 2 až 99 krát za sekundu.
#include <stdio.h>
#include <stdlib.h;>
#include <fcntl.h>
#include <time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/time.h>
#include <linux/hpet.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <signal.h>
static uint16_t hpet_sigio_count;
static uint64_t secs;
static void
hpet_alarm(int val)
{
struct timespec t;
clock_gettime(CLOCK_REALTIME, &t);
if (!secs) secs = t.tv_sec;
fprintf(stderr, "hpet_alarm called. iteration: %2d secs: %ld nsecs: %ld \n",
hpet_sigio_count, (t.tv_sec - secs) , t.tv_sec * 100000 + t.tv_nsec );
hpet_sigio_count++;
}
int
main(int argc, const char **argv)
{
struct sigaction old, new;
struct hpet_info info;
int frequency;
int iterations;
int retval = 0;
int fd;
int r, i, value;
if (argc != 3) {
fprintf(stderr, "Usage: %s frequency(1-64) iterations(10-99)\n", argv[0]);
return -1;
}
frequency = atoi(argv[1]);
iterations = atoi(argv[2]);
if (frequency > 64 || frequency < 1 ) {
fprintf(stderr, "ERROR: Invalid value for frequency\n");
return -1;
}
if (iterations < 10 || iterations > 99 ) {
fprintf(stderr, "ERROR: Invalid value for iterations\n");
return -1;
}
hpet_sigio_count = 0;
sigemptyset(&new.sa_mask);
new.sa_flags = 0;
new.sa_handler = hpet_alarm;
sigaction(SIGIO, NULL, &old);
sigaction(SIGIO, &new, NULL);
fd = open("/dev/hpet", O_RDONLY);
if (fd < 0) {
fprintf(stderr, "ERROR: Failed to open /dev/hpet\n");
return -1;
}
if ((fcntl(fd, F_SETOWN, getpid()) == 1) ||
((value = fcntl(fd, F_GETFL)) == 1) ||
(fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) {
fprintf(stderr, "ERROR: fcntl failed\n");
retval = 1;
goto fail;
}
if (ioctl(fd, HPET_IRQFREQ, frequency) < 0) {
fprintf(stderr, "ERROR: Could not set /dev/hpet to have a %2dHz timer\n", frequency);
retval = 2;
goto fail;
}
if (ioctl(fd, HPET_INFO, &info) < 0) {
fprintf(stderr, "ERROR: failed to get info\n");
retval = 3;
goto fail;
}
fprintf(stdout, "\nhi_ireqfreq: 0x%lx hi_flags: %0x%lx hi_hpet: 0x%x hi_timer: 0x%x\n\n",
info.hi_ireqfreq, info.hi_flags, info.hi_hpet, info.hi_timer);
r = ioctl(fd, HPET_EPI, 0);
if (info.hi_flags && (r < 0)) {
fprintf(stderr, "ERROR: HPET_EPI failed\n");
retval = 4;
goto fail;
}
if (ioctl(fd, HPET_IE_ON, 0) < 0) {
fprintf(stderr, "ERROR: HPET_IE_ON failed\n");
retval = 5;
goto fail;
}
/* wait for specified number of signal interrupts */
for (i = 0; i < iterations; i++) {
(void) pause();
}
if (ioctl(fd, HPET_IE_OFF, 0) < 0) {
fprintf(stderr, "ERROR: HPET_IE_OFF failed\n");
retval = 6;
}
fail:
sigaction(SIGIO, &old, NULL);
if (fd > 0)
close(fd);
return retval;
}
Here is the output from this example when it is invoked with a frequency of 32 and an iteration count of 64. Tu je výstup z tohto príkladu, kedy je uplatnený s frekvenciou 32 a počet iterácií 64.
$ sudo ./hpet_example 32 64 hi_ireqfreq: 0x20 hi_flags: 00 hi_hpet: 0x2 hi_timer: 0x4a1cb9c8 hpet_alarm called. iteration: 0 secs: 0 nsecs: 124683205055050 hpet_alarm called. iteration: 1 secs: 0 nsecs: 124683236313149 hpet_alarm called. iteration: 2 secs: 0 nsecs: 124683267566342 hpet_alarm called. iteration: 3 secs: 0 nsecs: 124683298821905 hpet_alarm called. iteration: 4 secs: 0 nsecs: 124683330077493 hpet_alarm called. iteration: 5 secs: 0 nsecs: 124683361341893 hpet_alarm called. iteration: 6 secs: 0 nsecs: 124683392590764 hpet_alarm called. iteration: 7 secs: 0 nsecs: 124683423849157 hpet_alarm called. iteration: 8 secs: 0 nsecs: 124683455101917 hpet_alarm called. iteration: 9 secs: 0 nsecs: 124683486357683 hpet_alarm called. iteration: 10 secs: 0 nsecs: 124683517617931 hpet_alarm called. iteration: 11 secs: 0 nsecs: 124683548872198 hpet_alarm called. iteration: 12 secs: 1 nsecs: 124682580229541 hpet_alarm called. iteration: 13 secs: 1 nsecs: 124682611481235 hpet_alarm called. iteration: 14 secs: 1 nsecs: 124682642740016 hpet_alarm called. iteration: 15 secs: 1 nsecs: 124682673992697 hpet_alarm called. iteration: 16 secs: 1 nsecs: 124682705247479 hpet_alarm called. iteration: 17 secs: 1 nsecs: 124682736504664 hpet_alarm called. iteration: 18 secs: 1 nsecs: 124682767758840 hpet_alarm called. iteration: 19 secs: 1 nsecs: 124682799014280 hpet_alarm called. iteration: 20 secs: 1 nsecs: 124682830270129 hpet_alarm called. iteration: 21 secs: 1 nsecs: 124682861530334 hpet_alarm called. iteration: 22 secs: 1 nsecs: 124682892784577 hpet_alarm called. iteration: 23 secs: 1 nsecs: 124682924038220 hpet_alarm called. iteration: 24 secs: 1 nsecs: 124682955294110 hpet_alarm called. iteration: 25 secs: 1 nsecs: 124682986550572 hpet_alarm called. iteration: 26 secs: 1 nsecs: 124683017805756 hpet_alarm called. iteration: 27 secs: 1 nsecs: 124683049061117 hpet_alarm called. iteration: 28 secs: 1 nsecs: 124683080318331 hpet_alarm called. iteration: 29 secs: 1 nsecs: 124683111576954 hpet_alarm called. iteration: 30 secs: 1 nsecs: 124683142828988 hpet_alarm called. iteration: 31 secs: 1 nsecs: 124683174083954 hpet_alarm called. iteration: 32 secs: 1 nsecs: 124683205337967 hpet_alarm called. iteration: 33 secs: 1 nsecs: 124683236593144 hpet_alarm called. iteration: 34 secs: 1 nsecs: 124683267851530 hpet_alarm called. iteration: 35 secs: 1 nsecs: 124683299104054 hpet_alarm called. iteration: 36 secs: 1 nsecs: 124683330358748 hpet_alarm called. iteration: 37 secs: 1 nsecs: 124683361617445 hpet_alarm called. iteration: 38 secs: 1 nsecs: 124683392870249 hpet_alarm called. iteration: 39 secs: 1 nsecs: 124683424124489 hpet_alarm called. iteration: 40 secs: 1 nsecs: 124683455379717 hpet_alarm called. iteration: 41 secs: 1 nsecs: 124683486634424 hpet_alarm called. iteration: 42 secs: 1 nsecs: 124683517889149 hpet_alarm called. iteration: 43 secs: 1 nsecs: 124683549144315 hpet_alarm called. iteration: 44 secs: 2 nsecs: 124682580500695 hpet_alarm called. iteration: 45 secs: 2 nsecs: 124682611761325 hpet_alarm called. iteration: 46 secs: 2 nsecs: 124682643011863 hpet_alarm called. iteration: 47 secs: 2 nsecs: 124682674265864 hpet_alarm called. iteration: 48 secs: 2 nsecs: 124682705521034 hpet_alarm called. iteration: 49 secs: 2 nsecs: 124682736776049 hpet_alarm called. iteration: 50 secs: 2 nsecs: 124682768030654 hpet_alarm called. iteration: 51 secs: 2 nsecs: 124682799285398 hpet_alarm called. iteration: 52 secs: 2 nsecs: 124682830544701 hpet_alarm called. iteration: 53 secs: 2 nsecs: 124682861797319 hpet_alarm called. iteration: 54 secs: 2 nsecs: 124682893051578 hpet_alarm called. iteration: 55 secs: 2 nsecs: 124682924306748 hpet_alarm called. iteration: 56 secs: 2 nsecs: 124682955562132 hpet_alarm called. iteration: 57 secs: 2 nsecs: 124682986823545 hpet_alarm called. iteration: 58 secs: 2 nsecs: 124683018073636 hpet_alarm called. iteration: 59 secs: 2 nsecs: 124683049327560 hpet_alarm called. iteration: 60 secs: 2 nsecs: 124683080586707 hpet_alarm called. iteration: 61 secs: 2 nsecs: 124683111841132 hpet_alarm called. iteration: 62 secs: 2 nsecs: 124683143095147 hpet_alarm called. iteration: 63 secs: 2 nsecs: 124683174349985 hpet_alarm called. iteration: 64 secs: 2 nsecs: 124683205607103 $
Well, I think that I have provided you with enough information so that you should now be able to go away and experiment with the HPET interface yourself. No, já myslím, že som poskytol vám dostatok informácií, takže by teraz mala byť schopní odísť a experimentovať s rozhraním HPET sami.
By the way, not all VMware products support HPET. Mimochodom, nie všetci VMware podporujú HPET. Currently ESX does not provide a virtual HPET to guest operating systems and in some cases it may be necessary to disable HPET altogether because of timer drift in virtual machines. V súčasnej dobe ESX neposkytuje virtuálne HPET pre hostované operačné systémy v niektorých prípadoch môže byť potrebné vypnúť HPET dohromady, pretože časovač posunu vo virtuálnych počítačoch. See Vidieť VMware TimeKeeping VMware časomerač for more information. pre viac informácií.
PS I tested the the above example on an Intel DX48BT2 motherboard running a 2.6.29.5-191 kernel. PS som skúšal vyššie uvedený príklad na základnej doske Intel DX48BT2 beží 2.6.29.5-191 jadra.
