".byte 0x3f" instructions in disassembly

[Graggi]

Hi,

I'm using xtensa-esp32-elf-objdump[1] to analysis some ESP32-Binaries. I noticed that sometimes 0x3f single byte instructions(?) can be found in the disassembly.

For example:

3f.png (69.07 KiB) Viewed 31241 times

I could not find any mentioning of this in the Xtensa-ISA[2]. Why are they placed there?

Regards

[1] https://github.com/badgeteam/xtensa-esp ... master/bin
[2] https://esp32.com/download/file.php?id=10134

[ESP_Sprite]

Objdump is not very smart and may be trying to decode non-instruction areas, like literal pools.

[ESP_igrr]

This could also be caused by the ELF file missing additional xtensa-specific sections; we have fixed this issue in https://github.com/espressif/esp-idf/co ... 98277fb3bb, but it could be that your ELF file was built with an IDF version which doesn't contain that fix.