github.com/platinasystems/nvram@v1.0.1-0.20190709235807-51a23abd5aec/cmos_entry.go (about) 1 // Copyright © 2019 Platina Systems, Inc. All rights reserved. 2 // Use of this source code is governed by the GPL-2 license described in the 3 // LICENSE file. 4 5 package nvram 6 7 import ( 8 "fmt" 9 ) 10 11 type CMOSEntryConfig byte 12 13 const ( 14 CMOSEntryEnum CMOSEntryConfig = 'e' 15 CMOSEntryHex CMOSEntryConfig = 'h' 16 CMOSEntryString CMOSEntryConfig = 's' 17 CMOSEntryReserved CMOSEntryConfig = 'r' 18 ) 19 20 type CMOSEntry struct { 21 bit uint 22 length uint 23 config CMOSEntryConfig 24 config_id uint 25 name string 26 } 27 28 func (e CMOSEntry) String() string { 29 return fmt.Sprintf("%d %d %c %d %s", e.bit, e.length, e.config, e.config_id, e.name) 30 } 31 32 func (e CMOSEntry) Bit() uint { 33 return e.bit 34 } 35 36 func (e CMOSEntry) Length() uint { 37 return e.length 38 } 39 40 func (e CMOSEntry) Config() CMOSEntryConfig { 41 return e.config 42 } 43 44 func (e CMOSEntry) ConfigId() uint { 45 return e.config_id 46 } 47 48 func (e CMOSEntry) Name() string { 49 return e.name 50 } 51 52 func verifyCMOSEntry(e *CMOSEntry) error { 53 // Check if entry is out of range. 54 if (e.bit >= (8 * cmosSize)) || ((e.bit + e.length) > (8 * cmosSize)) { 55 return fmt.Errorf("CMOS entry %s out of range.", e.name) 56 } 57 58 // Check if entry is unaligned and spanning multiple bytes. 59 if ((e.bit % 8) > 0) && ((e.bit / 8) != ((e.bit + e.length - 1) / 8)) { 60 return fmt.Errorf("CMOS entry %s unaligned spanning multiple bytes.", e.name) 61 } 62 63 // Check for a valid config type 64 switch e.config { 65 case CMOSEntryString: 66 case CMOSEntryEnum: 67 case CMOSEntryHex: 68 case CMOSEntryReserved: 69 default: 70 return fmt.Errorf("CMOS entry %s has invalid config type.", e.name) 71 } 72 73 return nil 74 } 75 76 func verifyCMOSOp(e *CMOSEntry) error { 77 // Check if entry is reserved 78 if e.config == CMOSEntryReserved { 79 return fmt.Errorf("CMOS entry %s is reserved.", e.name) 80 } 81 82 // Check if entry is in the RTC area 83 if e.bit < (8 * cmosRTCAreaSize) { 84 return fmt.Errorf("CMOS entry %s overlaps RTC.", e.name) 85 } 86 87 // Check if entry is more than 64 bits and not a string 88 if e.length > 64 && e.config != CMOSEntryString { 89 return fmt.Errorf("CMOS entry %s too wide.", e.name) 90 } 91 92 // Verify the rest of the entry 93 return verifyCMOSEntry(e) 94 } 95 96 func (e *CMOSEntry) IsOverlap(e1 *CMOSEntry) bool { 97 // Check if this entry overlaps another entry 98 return checkAreaOverLap(e.bit, e.length, e1.bit, e1.length) 99 } 100 101 func checkAreaOverLap(s0, l0, s1, l1 uint) bool { 102 e0 := s0 + l0 - 1 103 e1 := s1 + l1 - 1 104 return ((s1 <= e0) && (s0 <= e1)) 105 }