I have to translate a ld script to ARM Scatter syntax in order to use an ARM FuSa Compiler.

How are the commented parts from ld translated into scatter syntax?

ld:

.foo_data 
{
    . = ALIGN(4);              // This one
    __foo_data_start__ = .;    // This one
    *(.foo_shared_data)
    . = ALIGN(4);
    __foo_data_end__ = .;      // This one
} > foo_shareable

scat:

foo_data 0x20400000 0x0002FF00  
{
    foo_data _base 0x20400000
    {
        __foo_data_start__  Load$$LR$$int_sram$$Base
        __foo_data_start__  = .;
        __foo_data_start__  = 0x20400000;
        *(.foo_shared_data)
    }
}

I cannot access those symbols in my c code.

extern unsigned int __foo_data_start__;

int main(void)
{
    int bar = __foo_data_start__;
    
    return bar > 3 ? 0 : 1;
}

Error:

> armlink --cpu=cortex-m7 --scatter=scatter.scat --map --symbols main.o > foo
Error: L6218E: Undefined symbol __foo_data_start__ (referred from main.o).
Not enough information to list image symbols.

Any suggestions on that? The official ARM documentation is not that clear on that point.