Action name: OpOffsetCsThis command converts the immediate operand of the current instruction/data to an offset from the current segment (CS).
If the cursor is on the first operand (the cursor is before ',') then the first operand will be affected; otherwise, all other operands will be affected.
If a range is selected using the anchor, IDA will perform 'en masse' conversion. It will convert immediate operands of all instructions in the selected range to offsets. However, IDA will ask you first the lower and upper limits of immediate operand value. If the operand value is >= lower limit and <= upper limit then the operand will be converted to offset, otherwise, it will be left unmodified.
If this command is applied to a structure member in the structure window, then IDA will create an "automatic offset". An automatic offset is an offset with the base equal to 0xFFFFFFFF. This base value means that the actual value of the base will be calculated by IDA when a structure instance is created.
To create offsets to structure members, use Convert to struct offset command.
See also:
offset by data segment/no offset offset by any segment offset by any user-specified base Edit|Operand types|Offset submenu. Enter #th operand manually commands. Set operand type