Flash with program_esp on the first debug session too

[naelolaiz]

configure_debug_session switches the debugger's load step to program_esp only when every flash image already exists. pio debug configures the session before it builds the firmware, so the first session after a clean build, or on a new environment, finds no bootloader or partition table yet and falls back to GDB load. Depending on the chip, load then either fails (Load failed, flash addresses not writable) or writes the new ELF sections into flash through the mapping of the application already there, leaving an image whose checksum no longer matches, so the chip resets in a loop without reaching app_main. Sessions started on a project that was already built were not affected.

The images are build outputs that exist by the time GDB runs the load commands, so the check is dropped.

Tested:

• ESP32-S3 (ESP32-S3-WROOM-1, esp32-s3-devkitc-1, debug_tool = esp-builtin, the pinned OpenOCD v0.11.0-esp32-20220706), examples/espidf-hello-world, first pio debug after rm -rf .pio:
  • Current develop: GDB falls back to load, which cannot write the flash sections (Warn : address 0x3c010020 not writable) and ends in Load failed; the session never starts.
  • With this change: program_esp writes and verifies the bootloader, partition table and application (** Verify OK ** three times), and the session stops at app_main.
• ESP32-S31 (with the S31 support branch, see Add support for ESP32-S31 (ESP32-S31-Function-CoreBoard-1) #1777): before the change, the first pio debug after a clean build ran GDB load and the board reset in a loop; with it, the first session flashes with program_esp.
• esp32dev and esp32-c6-devkitm-1 with no images built yet: the load commands change from load to monitor program_esp for bootloader, partition table and application, in the format OpenOCD v0.11 expects.