ARM Compiler toolchain Linker Reference: Expression rules in scatter files

Expression rules in scatter files

Expressions follow the C-Precedence rules and are made up of the following:

Decimal or hexadecimal numbers.
Arithmetic operators: +, -, /, *, ~, OR, and AND
The OR and AND operators map to the C operators | and & respectively.
Logical operators: LOR, LAND, and !
The LOR and LAND operators map to the C operators || and && respectively.
Relational operators: <, <=, >, >=, and ==
Zero is returned when the expression evaluates to false and nonzero is returned when true.
Conditional operator: Expression ? Expression1 : Expression2
This matches the C conditional operator. If Expression evaluates to nonzero then Expression1 is evaluated otherwise Expression2 is evaluated.
Note
When using a conditional operator in a +offset context on an execution region or load region description, the final expression is considered relative only if both Expression1 and Expression2, are considered relative. For example:
```
er1 0x8000
{
    ...
}
er2 ((ImageLimit(er1) < 0x9000) ? +0 : +0x1000)    ; er2 has a relative address
{
    ...
}
er3 ((ImageLimit(er2) < 0x10000) ? 0x0 : +0)       ; er3 has an absolute address
{
    ...
}
```
Functions that return numbers.

All operators match their C counterparts in meaning and precedence.

Expressions are not case sensitive and you can use parentheses for clarity.

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