How to specify custom section start addresses for PE sections?

Question

On Linux, when linking I can specify any virtual address for a section:

ld -Ttext 0x10000000 -Tdata 0x20000000 foo.o -o foo

But I don't see such option for Windows' link.exe.

Is it possible to specify PE section start addresses somehow?

That's because such an option simply doesn't exist. Sections can be loaded at any VM address, code and data references are relocatable on Windows. — Hans Passant, Sep 12 '13 at 16:36
@HansPassant MinGW ld can do it somehow. Dumpbinning such binary reveals that it places the sections at base address + section address. And debugging such process showed me that text and data is at those addresses. I can use MinGW, but I would like to use the standard MSVC toolchain if possible. — Calmarius, Sep 12 '13 at 17:00

score 2 · Answer 1 · answered Sep 13 '13 at 12:12

MinGW ld can put the sections at arbitrary addresses. Dumpbin and disassemblers can handle it without problem.

But it seems Windows does not accept anything but the default address: if you try to set it to a different value Windows will say "not a valid Win32 application".

The base address must be 0x400000 or 0x1000000.

And the .text section must be at 0x401000 or 0x1001000.

Also it seems no gaps allowed between the sections. If I try to place the .data section to 0x403000 instead of 0x402000, then Windows is unable to load it...

(I maybe wrong, or mingw ld is buggy...)

score 0 · Answer 2 · edited May 23 '17 at 10:30

When using GCC, this page explains how to define variables at absolute addresses (including mentioning the section in which they should reside) : https://mcuoneclipse.com/2012/11/01/defining-variables-at-absolute-addresses-with-gcc/

The idea I use here is to put the variable with a special section name, and then place it in the linker file at an absolute address.
unsigned char __attribute__((section (".myBufSection"))) buf[128]
__attribute__ ((aligned (512)));
With this, my variable will be put into a section named ‘.myBufSection’, and it will be aligned on a 512 address boundary. The next step is to place that section at an address in the linker file.
SECTIONS
{
  /* placing my named section at given address: */
  .myBufBlock 0x20000000 :
  {
    KEEP(*(.myBufSection)) /* keep my variable even if not referenced */
  } > m_data

  /* other placements follow here... */
}

PS: Another method is mentioned in How can I declare a variable at an absolute address with GCC?

PS 2: Another related (alas unanswered) question is this : How to place a variable at a given absolute address in memory (with Visual C++)

Does anyone know of a method for Visual C(++) ? – PatrickvL Feb 27 '17 at 10:50 — PatrickvL, Feb 27 '17 at 10:50

How to specify custom section start addresses for PE sections?

2 Answers2