Files
linux-kernel-module-cheat/baremetal/arch/aarch64/timer.c
Ciro Santilli 六四事件 法轮功 e855a262fd aarch64 baremetal svc factored out for C and asm
2019-02-18 00:00:00 +00:00

43 lines
1.3 KiB
C

#include <stdio.h>
#include <inttypes.h>
#include <lkmc.h>
#define CNTV_CTL_ENABLE (1 << 0)
#define CNTV_CTL_IMASK (1 << 1)
#define CNTV_CTL_ISTATUS (1 << 2)
void cntv_ctl_el0_disable(void) {
lkmc_sysreg_cntv_ctl_el0_write(lkmc_sysreg_cntv_ctl_el0_read() & ~CNTV_CTL_ENABLE);
}
/* If enabled, when: cntv_ctl > cntv_cval then:
*
* * if CNTV_CTL_IMASK is clear, raise an interrupt
* * set CNTV_CTL_ISTATUS
*/
void cntv_ctl_el0_enable(void) {
lkmc_sysreg_cntv_ctl_el0_write(lkmc_sysreg_cntv_ctl_el0_read() | CNTV_CTL_ENABLE);
}
int main(void) {
/* Initial state. */
printf("cntv_ctl_el0 0x%" PRIx32 "\n", lkmc_sysreg_cntv_ctl_el0_read());
printf("cntfrq_el0 0x%" PRIx64 "\n", lkmc_sysreg_cntfrq_el0_read());
printf("cntv_cval_el0 0x%" PRIx64 "\n", lkmc_sysreg_cntv_cval_el0_read());
/* Get the counter value many times to watch the time pass. */
printf("cntvct_el0 0x%" PRIx64 "\n", lkmc_sysreg_cntvct_el0_read());
printf("cntvct_el0 0x%" PRIx64 "\n", lkmc_sysreg_cntvct_el0_read());
printf("cntvct_el0 0x%" PRIx64 "\n", lkmc_sysreg_cntvct_el0_read());
#if 0
/* TODO crashes gem5. */
puts("cntfrq_el0 = 1");
lkmc_sysreg_cntfrq_el0_write(1);
printf("cntfrq_el0 0x%" PRIx64 "\n", lkmc_sysreg_cntfrq_el0_read());
#endif
return 0;
}