Generate an ELF 64-bit executable by hand. This is an example
of how to manually create an ELF 64 executable for linux that
will print out some string and then exit using sys_write and
sys_exit linus system calls.
It will generate the ELF header, then 2 Program Headers (one
for the .text segment and one for the .data segment). Then the
.text segment and .data segment are outputted to the binary.
The .text segment will do a sys_write using the data offset
from where the .data segment is located and then it will do
a sys_exit.
The .data segment contains just the string data.
This doesn't currently do back-patching. The data segment is always known since the ELF header and text segment aren't changing. This needs to be fixed, but I don't know a good way to do it.
$ go run main.go
wrote binary to tiny-x64
$ ./tiny-x64
Hello World, this is my tiny executable
$ ls -hal ./tiny-x64
-rwxr-xr-x 1 vishen vishen 257 Jun 21 08:58 ./tiny-x64*
# Or run with a desired string to output in the binary
$ go run main.go -output hello-world -word "Hello, World!"
wrote binary to hello-world
$ ./hello-world
Hello, World!
$ ls -hal ./hello-world
-rwxr-xr-x 1 vishen vishen 231 Jun 21 08:59 ./hello-world*