github.com/notti/nocgo@v0.0.0-20190619201224-fc443047424c/steps/1_dynamic/README.md (about)

     1  ASM static binary -> dynamic loading without linking with `ld`
     2  ==============================================================
     3  
     4  This directory contains the same 42.asm as 0_static, with an added call to `__printf` and argument "hello world" that will be replaced by `puts` from glibc.
     5  
     6  `rewrite.go` takes `a.out` as input and outputs `dyn` with changed elf headers so that:
     7  1. `interp` is added so we get loaded dynamically
     8  2. `libc.so.6` is added as needed library
     9  3. contents of `__printf` in `.bss` get changed to point to `puts` from `libc.so.6`
    10  4. profit: `./dyn` outputs `hello world`, is statically compiled (without libc!), but can call into the dynamic symbol `puts`