IDA Help: Change Segment Register Value

 Action    name: SetSegmentRegister
 

Relevant only for processors with the segment registers. Currently this command works for IBM PC, TMS320C2, Intel80196, and PowerPC processors.

This command creates or updates a segment register change point.

See jump to segment register change point for more info.

ALPHA DISASSEMBLY

For Alpha processors, the user must enter the difference between the real GP value and the start of the GOT (global offset table). For example:

         .got
         ....
         ; gp points here
 label:

If you want to specify that a register points to "label", you must calculate and enter the difference "label-.got" as the register value.

ARM DISASSEMBLY

The ARM processor module has a virtual segment register T which reflects the state of the T bit of the processor state register (PSR). Therefore, the value of this register controls THUMB/ARM mode. If its value is not zero, then the disassembly will be in the thumb mode.

POWER PC DISASSEMBLY

For PowerPC processors, the user must enter an offset from the beginning of the TOC to the TOC entry which contains the address of the target. An example:

 TOC:    .toc
         ....
 sometc: .tc sometc[tc], datachunk

If you want to specify that a register points to "datachunk", you must calculate and enter the difference "sometc-TOC" as the register value. You can change the TOC value in the processor specific options (which is accessible from the analysis options).

INTEL 80196 DISASSEMBLY

For Intel 80196NP/NU processors, the user must enter the value of WSR or WSR1 register. IDA will automatically take the new value into account.

 See also Edit|Segments submenu.
 See also How to enter segment value.
 See also How to Enter a Number.

Index | Previous topic | Next topic