Comment 6 for bug 1914021

Oh, your code is trying to use the SYS_HEAPINFO semihosting call to figure out where the stack and heap are. This is generally a bad idea if you're using QEMU user-mode emulation: you start with a perfectly good stack pointer and you should just use the usual Linux syscalls to allocate heap if you need it.

I have no idea where your code is getting r1 from -- it's too painful to try to reverse-engineer it from the binary. I can't repro any difference between with-gdb and without -- for me with current QEMU r1 is 0 whether running with the gdb stub or not.