Flashing with ESP32-S3 with Octal flash flashes an unbootable image

[MabezDev]

After installing RC4 I noticed that flashing with the USB-SERIAL-JTAG port (in my case, S3) no longer correctly flashes the chip. The second stage bootloader complains about the partition table having partition size. I bisected from a known working state to find that #375 seems to be the culprit.

ESP-ROM:esp32s3-20210327
Build:Mar 27 2021
rst:0x3 (RTC_SW_SYS_RST),boot:0x18 (SPI_FAST_FLASH_BOOT)
Saved PC:0x403cdb4a
0x403cdb4a - __default_naked_level_7_interrupt
    at ??:??
SPIWP:0xee
Octal Flash Mode Enabled
For OPI Flash, Use Default Flash Boot Mode
mode:SLOW_RD, clock div:2
load:0x3fce3810,len:0x1690
0x3fce3810 - _stack_end_cpu0
    at ??:??
load:0x403c9700,len:0xbd0
0x403c9700 - __default_naked_level_7_interrupt
    at ??:??
load:0x403cc700,len:0x2dc8
0x403cc700 - __default_naked_level_7_interrupt
    at ??:??
SHA-256 comparison failed:
Calculated: ae126cb96d962b79703c4a4144654f513bc92dbad93c921b2e20c5558d0914dc
Expected: d1c78d7325094d95e7bb525e04f54c3212a0971c36efb48e3f3f056daece1a5e
Attempting to boot anyway...
entry 0x403c9900
0x403c9900 - __default_naked_level_7_interrupt
    at ??:??
I (60) boot: ESP-IDF v5.0-beta1-764-gdbcf640261 2nd stage bootloader
I (60) boot: compile time 11:32:39
I (60) boot: chip revision: V000
I (64) boot.esp32s3: Boot SPI Speed : 40MHz
I (69) boot.esp32s3: SPI Mode       : SLOW READ
I (74) boot.esp32s3: SPI Flash Size : 32MB
I (79) boot: Enabling RNG early entropy source...
I (84) boot: Partition Table:
I (88) boot: ## Label            Usage          Type ST Offset   Length
I (95) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (102) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (110) boot:  2 factory          factory app      00 00 00010000 01ff0000
I (117) boot: End of partition table
E (122) esp_image: partition size 0x1ff0000 invalid, larger than 16MB
E (129) boot: Factory app partition is not bootable
E (134) boot: No bootable app partitions in the partition table

Looking at the changes in #375, I'm not sure what would cause this. @maxwase, could you test flashing on your S3 board via USB serial jtag to verify this is a real issue?

[MabezDev]

Edit, I actually found this happens regardless of flashing via USB-SERIAL-JTAG or the USB serial converter.

[MabezDev]

I found an S3 board which doesn't have Octal flash on it, and it works just fine... Hmmm.

[maxwase]

I tied to reproduce this, but got... the opposite results
I'm unable to flash S3 before my bootloader changes, so I tried to flash hello_world example from esp-idf repository. Surprisingly, my esp went into a bootloop with
E (277) spi_flash: Detected size(512k) smaller than the size in the binary image header(32768k). Probe failed. message.
Out of curiosity I selected octal flash mode using idf.py menuconfig -> Serial flasher config -> Enable Octal Flash and flashed the helloworld image once again and it booted without any problem (note that I've flashed bootloader before)

Next, I tried to flash rusty blinky image and got the same bootloop error, so I tried to specify octal flash settings in sdkconfig.defaults:

CONFIG_ESPTOOLPY_OCT_FLASH=y
CONFIG_ESPTOOLPY_FLASH_SAMPLE_MODE_STR=y

Magically, it booted successfully, although I did receive some warnings that I always had.

This behavior is especially interesting because I was able to flash both helloworld and rust blinky examples before without octal mode. If I remember correctly, idf and toolchain versions are the same as before.

[maxwase]

UPD: Reproduced with explicit partition table that has >16 MB partition. This issue has not been seen before due to wrong size-freq config in the header