Inconsistent use of TEXT_LOCATION_FLASH_ATTRIBUTE breaks OTA asset binary sharing

[grisa199678]

We are implementing a software-driven OTA update system using TouchGFX and a 64MB external QSPI flash. We store the following asset sections in QSPI:

• ExtFlashSection

• FontFlashSection

• TextFlashSection

These are bundled into an ExternalFlash.bin asset file, which should be shared between firmware partitions (A/B). Since the data contains only static assets, it must remain bank-independent for OTA to work properly.

Problem:

In the generated TypedTextDatabase.cpp, the following array is incorrectly marked with TEXT_LOCATION_FLASH_ATTRIBUTE:

TEXT_LOCATION_FLASH_PRAGMA
const touchgfx::TypedText::TypedTextData* const typedTextDatabaseArray[] TEXT_LOCATION_FLASH_ATTRIBUTE = {
    typedText_database_GB,
    typedText_database_ESP
};

This array is placed into TextFlashSection, which is part of ExternalFlash.bin. However, the array contains pointers to other flash-resident data (typedText_database_GB, etc.), which are already placed correctly in TextFlashSection.

Storing the array itself in flash causes absolute addresses to be written into ExternalFlash.bin, which ties it to the current firmware bank — defeating OTA partition independence.

Inconsistency in Code Generation:

This issue appears to be a code generation oversight, because in other sections (e.g., ExtFlashSection, FontFlashSection), the generated arrays do not use TEXT_LOCATION_FLASH_ATTRIBUTE. For example:

const touchgfx::Font* const fontList[] = {
    &font_roboto_16_4bpp,
    &font_roboto_24_4bpp
};

These arrays are placed in RAM, and only reference data located in external flash — which is the correct and expected behavior.

So, it's clear this is not a design choice, but a developer inconsistency in how typedTextDatabaseArray is handled.

Proposed Fix:

Remove the TEXT_LOCATION_FLASH_ATTRIBUTE (and pragma) from the array declaration in TypedTextDatabase.cpp:

const touchgfx::TypedText::TypedTextData* const typedTextDatabaseArray[] = {
    typedText_database_GB,
    typedText_database_ESP
};

With this fix:

• The array is stored in RAM (in firmware partition A or B)

• It references data in external flash (QSPI-mapped)

• The asset binary remains bank-independent

Target Setup:

• MCU: STM32F769NIHx

• Board: STM32F769I-DISCO

• TouchGFX Version: 4.24.2

• External Flash: 64MB QSPI

• Asset Sections Used: ExtFlashSection, FontFlashSection, TextFlashSection