Ok, I got it: I've forgot to set the swizzle options on the last dword of the resource dqword. Somehow I thought, a simple 0 will do it, but not.
So if anybody run into this: this is a working resource descriptor that points to address 0:
s_movk_i32 s0, 0 //address_lo 0
s_movk_i32 s1, 0 //address_hi 0, stride 0
s_movk_i32 s2, -1 //no limit
s_mov_b32 s3, 0x8027fac //set the swizzle format to no swizzle