github.com/arduino/arduino-cloud-cli@v0.0.0-20240517070944-e7a449561083/internal/ota/version.go (about)

     1  // This file is part of arduino-cloud-cli.
     2  //
     3  // Copyright (C) 2021 ARDUINO SA (http://www.arduino.cc/)
     4  //
     5  // This program is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU Affero General Public License as published
     7  // by the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // This program is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13  // GNU Affero General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU Affero General Public License
    16  // along with this program.  If not, see <https://www.gnu.org/licenses/>.
    17  
    18  package ota
    19  
    20  const compressionEnabledMagicNumber = 0x40
    21  
    22  // Version contains all the OTA header information
    23  // Check out https://arduino.atlassian.net/wiki/spaces/RFC/pages/1616871540/OTA+header+structure for more
    24  // information on the OTA header specs.
    25  type Version struct {
    26  	HeaderVersion   uint8
    27  	Compression     bool
    28  	Signature       bool
    29  	Spare           uint8
    30  	PayloadTarget   uint8
    31  	PayloadMayor    uint8
    32  	PayloadMinor    uint8
    33  	PayloadPatch    uint8
    34  	PayloadBuildNum uint32
    35  }
    36  
    37  // Bytes builds a 8 byte length representation of the Version Struct for the OTA update.
    38  func (v *Version) Bytes() []byte {
    39  	version := []byte{0, 0, 0, 0, 0, 0, 0, 0}
    40  
    41  	// Set compression
    42  	if v.Compression {
    43  		version[7] = 0x40
    44  	}
    45  
    46  	// Other field are currently not implemented ¯\_(ツ)_/¯
    47  
    48  	return version
    49  }
    50  
    51  // Bytes builds a 8 byte length representation of the Version Struct for the OTA update.
    52  func decodeVersion(version []byte) Version {
    53  
    54  	compressed := (version[7] == compressionEnabledMagicNumber)
    55  
    56  	// Other field are currently not implemented ¯\_(ツ)_/¯
    57  
    58  	return Version{
    59  		Compression: compressed,
    60  	}
    61  }