| \ ***************************************************************************** |
| \ * Copyright (c) 2004, 2008 IBM Corporation |
| \ * All rights reserved. |
| \ * This program and the accompanying materials |
| \ * are made available under the terms of the BSD License |
| \ * which accompanies this distribution, and is available at |
| \ * http://www.opensource.org/licenses/bsd-license.php |
| \ * |
| \ * Contributors: |
| \ * IBM Corporation - initial implementation |
| \ ****************************************************************************/ |
| |
| |
| \ Use the HPET to calculate various frequencies. |
| |
| \ Make HPET run. |
| 1 10 hpet! |
| |
| \ Set PMC1 to count CPU cycles. |
| f00 mmcr0! |
| |
| d# 1000000000000000 4 hpet@ / CONSTANT hpet-freq |
| |
| : get-times tbl@ pmc1@ f0 hpet@ ; |
| |
| \ Calculate the CPU and TB frequencies. |
| : calibrate get-times dup >r swap >r swap >r hpet-freq d# 100 / + >r |
| BEGIN get-times dup r@ < WHILE 3drop REPEAT r> drop |
| rot r> - ffffffff and \ TB |
| rot r> - ffffffff and \ CPU |
| rot r> - >r \ HPET |
| hpet-freq * r@ / swap |
| hpet-freq * r> / ; |
| |
| : round-to tuck 2/ + over / * ; |
| calibrate TO tb-frequency d# 100000000 round-to TO cpu-frequency |
| |
| \ Stop HPET. |
| 0 10 hpet! |