AVRDisassembler is a new open source, cross platform (Windows, Mac, Linux) disassembler for the AVR microcontroller platform, written in C# (.NET Core). It supports the full instruction set as described by the ATMEL 0856 Instruction Set Documentation. The code is made available under the MIT license.
Note: Full source code for the disassembler can be found on GitHub: AVRDisassembler.
Command line usage
Using the disassembler is very straightforward. Invoke it from the command line without arguments to get its usage documented:
AVRDisassembler 0.1.0
ERROR(S):
Required option 'i, input' is missing.
-i, --input Required. Input file (HEX) to be disassembled.
--json (Default: false) Format output as JSON.
--help Display this help screen.
--version Display version information.Sample output:
...
0FE4: 50-93-2B-02 sts 0x022b, r21 ; Store Direct to Data Space
0FE8: 40-93-2A-02 sts 0x022a, r20 ; Store Direct to Data Space
0FEC: F9-01 movw r30, r18 ; Copy Register Word
0FEE: E6-56 subi r30, 0x66 ; Subtract Immediate
0FF0: FF-4F sbci r31, 0xff ; Subtract Immediate with Carry SBI
0FF2: 24-91 lpm r18, Z ; Load Program Memory
0FF4: 20-93-29-02 sts 0x0229, r18 ; Store Direct to Data Space
0FF8: 31-2C mov r3, r1 ; Copy Register
0FFA: 53-C0 rjmp .+166 ; Relative Jump
0FFC: 10-92-80-00 sts 0x0080, r1 ; Store Direct to Data Space
1000: 10-92-81-00 sts 0x0081, r1 ; Store Direct to Data Space
1004: 90-91-81-00 lds r25, 0x0081 ; Load Direct from Data Space (32-bit)
1008: 98-60 ori r25, 0x08 ; Logical OR with Immediate
100A: 90-93-81-00 sts 0x0081, r25 ; Store Direct to Data Space
100E: 90-91-81-00 lds r25, 0x0081 ; Load Direct from Data Space (32-bit)
1012: 91-60 ori r25, 0x01 ; Logical OR with Immediate
1014: 90-93-81-00 sts 0x0081, r25 ; Store Direct to Data Space
1018: 28-2F mov r18, r24 ; Copy Register
101A: 30-E0 ldi r19, 0x00 ; Load Immediate
101C: F9-01 movw r30, r18 ; Copy Register Word
101E: E2-55 subi r30, 0x52 ; Subtract Immediate
1020: FF-4F sbci r31, 0xff ; Subtract Immediate with Carry SBI
1022: E4-91 lpm r30, Z ; Load Program Memory
1024: F0-E0 ldi r31, 0x00 ; Load Immediate
1026: EE-0F add r30, r30 ; Add without Carry
1028: FF-1F adc r31, r31 ; Add with Carry
102A: E4-53 subi r30, 0x34 ; Subtract Immediate
102C: FF-4F sbci r31, 0xff ; Subtract Immediate with Carry SBI
102E: 45-91 lpm r20, Z+ ; Load Program Memory
1030: 54-91 lpm r21, Z ; Load Program Memory
1032: 50-93-24-02 sts 0x0224, r21 ; Store Direct to Data Space
1036: 40-93-23-02 sts 0x0223, r20 ; Store Direct to Data Space
103A: F9-01 movw r30, r18 ; Copy Register Word
103C: E6-56 subi r30, 0x66 ; Subtract Immediate
103E: FF-4F sbci r31, 0xff ; Subtract Immediate with Carry SBI
1040: 24-91 lpm r18, Z ; Load Program Memory
1042: 20-93-22-02 sts 0x0222, r18 ; Store Direct to Data Space
...The fine print
- Only raw HEX files are supported. It would be great to build ELF support, as we could then also support fancy source / debug information interleaving.
- There is a nuget package for .NET style integration. Since it’s the first release, it is marked as prerelease.
- Other languages may consume the JSON output and use that as a building block.
- The disassembler assumes a non reduced / non “brain dead” core (e.g. no LDS16 instruction usage).
- When multiple instructions are viable (synonyms), the disassembler will simply pick the “first” out of it’s internal matching options (this should be made configurable in some way).