Any of the following would be extremely helpful:
A minimal working snippet of a bare-metal jump to an app in external Flash on ESP32.

Please have a look at https://github.com/igrr/p155310-boot-demo. Disclaimer: code written by AI; I reviewed it afterwards, it looks correct.


Q1. What is the ...

so that parameters such as IP address, device name, and password can be changed without editing my code.


And yet another option, if you want to avoid even rebuilding the app when these variables change, you can use a component I wrote:
https://components.espressif.com/components/igrr/nvs ...

That's not the case; image metadata is part of the binary image itself. You can find out more about the binary image format over here: https://docs.espressif.com/projects/esptool/en/latest/esp32/advanced-topics/firmware-image-format.html.

As Sprite wrote, in the original ESP32, the first 4k region ...

Hi Burtrum,

Currently the only "buildv2" application in ESP-IDF is this test app: https://github.com/espressif/esp-idf/tree/master/tools/test_build_system/buildv2_test_app. It is very simple and doesn't show all the ways buildv2 can be used.
We have a task internally to add examples for buildv2, we ...

Yes, ESP32-S3 can communicate with an eMMC chip over 8-bit SD interface. You can check the supported speed modes over at https://docs.espressif.com/projects/esp-idf/en/latest/esp32s3/api-reference/peripherals/sdmmc_host.html#supported-speed-modes , and the example is https://github.com/espressif/esp ...

Hi ignisuti,

'main' component has a special behavior that by default, it adds all other components as dependencies. This is the reason why you can use nvs_flash component from "main" without explicitly adding nvs_flash as a dependency. Once you start creating additional components, you have to ...

so i am still a bit confused, especially it has impact on fps on S3.


I am not sure why adding this flag makes any difference on S3, either. Maybe you can try to log the pointer values returned by heap_caps_calloc with and without MALLOC_CAP_DMA and see if they are in the same memory region or ...

decided to write a simple bigbanging driver for it

MALLOC_CAP_DMA

If you are accessing a memory region by your bitbanging software driver only, there is no difference whether MALLOC_CAP_DMA is used or not. This flag requests memory which _can_ be used by DMA engines. DMA engines (like GDMA or ...

Hi Seon,

The note in sdmmc_card_init about eMMC not being supported is indeed outdated. Will remove it!


You are right that ESP32-C6 doesn't have SDMMC Host controller. You can call sdmmc_card_init on ESP32-C6, provided that you use SDSPI host. That is, you write:


sdmmc_host_t host = SDSPI_HOST ...

This issue occurs because you are compiling ESP-IDF v5.3 with toolchain esp-12.2.0_20230208. The correct version for IDF v5.3 is esp-13.2.0_20240530.

Can you please describe how you are compiling the project (command line, IDE, which OS, etc.)?