ESP32 related snippets

[marekmatej]

This PR provides snippets commonly needed when building targts with the Espressif SoCs.

• PSRAM - full utilization
• MCUboot - application type

[tejlmand]

Why is this a snippet ?

Please explain why -DSNIPPET=esp-mcuboot is cleaner, better, easier than -DCONFIG_BOOTLOADER_MCUBOOT=y

[marekmatej]

Yeah, the idea here is to use them in combination. I'm using -DSNIPPET="mcuboot;spiram", which is much shorter compared to adding -DCONFIG_BOOTLOADER_MCUBOOT=y

[marekmatej]

Why is this a snippet ?

Please explain why -DSNIPPET=esp-mcuboot is cleaner, better, easier than -DCONFIG_BOOTLOADER_MCUBOOT=y

We often need to switch between no-bootloader (simpleboot) to MCUBoot. And this - yes very primitive - mcuboot snippet allows us to use snippets in a linear fashion:
west build -p -b <board> <sample> -DSNIPPER="mcuboot;spiram;..."

[tejlmand]

If we want a snippet for enabling MCUBoot, then why is this an espressif specific snippet, and not just a MCUboot snippets which can do board/SoC specific stuff if that is needed ?

[marekmatej]

We are currently in the process of integrating the MCUboot Espressif Port into Zephyr, and it seems there will be additional configs involved

[tejlmand]

then I prefer we wait with a MCUboot specific snippet until we have a better view of what such snippet will actually do, and whether such snippet should have esp in it's name, or be a generic mcuboot snippet which can have special handling for esp SoCs.

[marekmatej]

I agree with you, and have renamed the mcuboot snippet files and identifiers.

[marekmatej]

@tejlmand ptal. I like the mcuboot snippet because it's shorter and allows sharing the image features as a single string.

[tejlmand]

I like the mcuboot snippet because it's shorter and allows sharing the image features as a single string.

but following such approach to its extreme would mean that any single Kconfig could end-up having a corresponding snippet.
What about the next snippet which simply enables just a single Kconfig, should that also be accepted ?

[marekmatej]

I like the mcuboot snippet because it's shorter and allows sharing the image features as a single string.

but following such approach to its extreme would mean that any single Kconfig could end-up having a corresponding snippet. What about the next snippet which simply enables just a single Kconfig, should that also be accepted ?

Hypothetically, but we are talking about enabling bootloader support. It is rather exception than a rule. Frankly, creating 3 new files just to enable single config is not a victory. But it makes perfect sense in this case.