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| author | Thomas Weißschuh <linux@weissschuh.net> | 2025-06-24 00:15:54 +0300 |
|---|---|---|
| committer | Thomas Weißschuh <linux@weissschuh.net> | 2025-07-04 14:26:07 +0300 |
| commit | 02217ad447d7b1dd592cfc8253a07375d0b32aa7 (patch) | |
| tree | fbbfcee49d68feb1cd4bd8b958c1d87dd673af36 /tools/include | |
| parent | 358b2511d7e687a243383fbbba9cb21b242f48b8 (diff) | |
| download | linux-02217ad447d7b1dd592cfc8253a07375d0b32aa7.tar.xz | |
tools/nolibc: add support for SuperH
Add support for SuperH/"sh" to nolibc.
Only sh4 is tested for now.
The startup code is special:
__nolibc_entrypoint_epilogue() calls __builtin_unreachable() which emits
a call to abort(). To make this work a function prologue is generated to
set up a GOT pointer which corrupts "sp".
__builtin_unreachable() is necessary for __attribute__((noreturn)).
Also depending on compiler flags (for example -fPIC) even more prologue
is generated.
Work around this by defining a nested function in asm.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70216
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Rob Landley <rob@landley.net>
Acked-by: D. Jeff Dionne <jeff@coresemi.io>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20250623-nolibc-sh-v2-3-0f5b4b303025@weissschuh.net
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/nolibc/arch-sh.h | 162 | ||||
| -rw-r--r-- | tools/include/nolibc/arch.h | 2 |
2 files changed, 164 insertions, 0 deletions
diff --git a/tools/include/nolibc/arch-sh.h b/tools/include/nolibc/arch-sh.h new file mode 100644 index 000000000000..a96b8914607e --- /dev/null +++ b/tools/include/nolibc/arch-sh.h @@ -0,0 +1,162 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* + * SuperH specific definitions for NOLIBC + * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net> + */ + +#ifndef _NOLIBC_ARCH_SH_H +#define _NOLIBC_ARCH_SH_H + +#include "compiler.h" +#include "crt.h" + +/* + * Syscalls for SuperH: + * - registers are 32bit wide + * - syscall number is passed in r3 + * - arguments are in r4, r5, r6, r7, r0, r1, r2 + * - the system call is performed by calling trapa #31 + * - syscall return value is in r0 + */ + +#define my_syscall0(num) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall1(num, arg1) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + register long _arg1 __asm__ ("r4") = (long)(arg1); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num), "r"(_arg1) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall2(num, arg1, arg2) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + register long _arg1 __asm__ ("r4") = (long)(arg1); \ + register long _arg2 __asm__ ("r5") = (long)(arg2); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num), "r"(_arg1), "r"(_arg2) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall3(num, arg1, arg2, arg3) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + register long _arg1 __asm__ ("r4") = (long)(arg1); \ + register long _arg2 __asm__ ("r5") = (long)(arg2); \ + register long _arg3 __asm__ ("r6") = (long)(arg3); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall4(num, arg1, arg2, arg3, arg4) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + register long _arg1 __asm__ ("r4") = (long)(arg1); \ + register long _arg2 __asm__ ("r5") = (long)(arg2); \ + register long _arg3 __asm__ ("r6") = (long)(arg3); \ + register long _arg4 __asm__ ("r7") = (long)(arg4); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + register long _arg1 __asm__ ("r4") = (long)(arg1); \ + register long _arg2 __asm__ ("r5") = (long)(arg2); \ + register long _arg3 __asm__ ("r6") = (long)(arg3); \ + register long _arg4 __asm__ ("r7") = (long)(arg4); \ + register long _arg5 __asm__ ("r0") = (long)(arg5); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \ + "r"(_arg5) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ +({ \ + register long _num __asm__ ("r3") = (num); \ + register long _ret __asm__ ("r0"); \ + register long _arg1 __asm__ ("r4") = (long)(arg1); \ + register long _arg2 __asm__ ("r5") = (long)(arg2); \ + register long _arg3 __asm__ ("r6") = (long)(arg3); \ + register long _arg4 __asm__ ("r7") = (long)(arg4); \ + register long _arg5 __asm__ ("r0") = (long)(arg5); \ + register long _arg6 __asm__ ("r1") = (long)(arg6); \ + \ + __asm__ volatile ( \ + "trapa #31" \ + : "=r"(_ret) \ + : "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \ + "r"(_arg5), "r"(_arg6) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +/* startup code */ +void _start_wrapper(void); +void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _start_wrapper(void) +{ + __asm__ volatile ( + ".global _start\n" /* The C function will have a prologue, */ + ".type _start, @function\n" /* corrupting "sp" */ + ".weak _start\n" + "_start:\n" + + "mov sp, r4\n" /* save argc pointer to r4, as arg1 of _start_c */ + "bsr _start_c\n" /* transfer to c runtime */ + "nop\n" /* delay slot */ + + ".size _start, .-_start\n" + ); + __nolibc_entrypoint_epilogue(); +} + +#endif /* _NOLIBC_ARCH_SH_H */ diff --git a/tools/include/nolibc/arch.h b/tools/include/nolibc/arch.h index db69537c71d8..426c89198135 100644 --- a/tools/include/nolibc/arch.h +++ b/tools/include/nolibc/arch.h @@ -35,6 +35,8 @@ #include "arch-sparc.h" #elif defined(__m68k__) #include "arch-m68k.h" +#elif defined(__sh__) +#include "arch-sh.h" #else #error Unsupported Architecture #endif |