1 /* 2 * This file and its contents are supplied under the terms of the 3 * Common Development and Distribution License ("CDDL"), version 1.0. 4 * You may only use this file in accordance with the terms of version 5 * 1.0 of the CDDL. 6 * 7 * A full copy of the text of the CDDL should have accompanied this 8 * source. A copy of the CDDL is also available via the Internet at 9 * http://www.illumos.org/license/CDDL. 10 */ 11 12 /* 13 * Copyright 2022 Oxide Computer Company 14 */ 15 16 #include "payload_common.h" 17 #include "payload_utils.h" 18 #include "test_defs.h" 19 20 21 void 22 timer0_reset(void) 23 { 24 /* 25 * Configure timer 0 for interrupt-on-terminal-count mode, and prepare 26 * it to be loaded with the high and low bytes. 27 */ 28 outb(IOP_ATPIT_CMD, 0x30); 29 30 /* Load timer with max value (0xffff) */ 31 outb(IOP_ATPIT_C0, 0xff); 32 outb(IOP_ATPIT_C0, 0xff); 33 } 34 35 uint16_t 36 timer0_read(void) 37 { 38 uint16_t val; 39 40 /* Latch timer0 */ 41 outb(IOP_ATPIT_CMD, 0x00); 42 43 /* Read low and high bytes */ 44 val = inb(IOP_ATPIT_C0); 45 val |= (uint16_t)inb(IOP_ATPIT_C0) << 8; 46 47 return (val); 48 } 49 50 void 51 start(void) 52 { 53 54 /* loop for as long as the host wants */ 55 for (;;) { 56 uint16_t start, end; 57 58 timer0_reset(); 59 60 start = timer0_read(); 61 outw(IOP_TEST_VALUE, start); 62 63 do { 64 end = timer0_read(); 65 /* wait for enough ticks to pass */ 66 } while (end > (start - ATPIT_TARGET_TICKS)); 67 outw(IOP_TEST_VALUE, end); 68 } 69 } 70