Commit Graph

5 Commits

Author SHA1 Message Date
Ammar Faizi 1590c59836 tools/nolibc: Remove .global _start from the entry point code
Building with clang yields the following error:
```
  <inline asm>:3:1: error: _start changed binding to STB_GLOBAL
  .global _start
  ^
  1 error generated.
```
Make sure only specify one between `.global _start` and `.weak _start`.
Remove `.global _start`.

Cc: llvm@lists.linux.dev
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi 37d62758e7 tools/nolibc: Replace `asm` with `__asm__`
Replace `asm` with `__asm__` to support compilation with -std flag.
Using `asm` with -std flag makes GCC think `asm()` is a function call
instead of an inline assembly.

GCC doc says:

  For the C language, the `asm` keyword is a GNU extension. When
  writing C code that can be compiled with `-ansi` and the `-std`
  options that select C dialects without GNU extensions, use
  `__asm__` instead of `asm`.

Link: https://gcc.gnu.org/onlinedocs/gcc/Basic-Asm.html
Reported-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi 5312aaa5d5 tools/nolibc: x86-64: Update System V ABI document link
The old link no longer works, update it.

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Willy Tarreau dffeb81af5 tools/nolibc/arch: mark the _start symbol as weak
By doing so we can link together multiple C files that have been compiled
with nolibc and which each have a _start symbol.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau 271661c1cd tools/nolibc/arch: split arch-specific code into individual files
In order to ease maintenance, this splits the arch-specific code into
one file per architecture. A common file "arch.h" is used to include the
right file among arch-* based on the detected architecture. Projects
which are already split per architecture could simply rename these
files to $arch/arch.h and get rid of the common arch.h. For this
reason, include guards were placed into each arch-specific file.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00