Hi, Thomas, Willy
> On Sun, Jul 23, 2023 at 09:32:37AM +0200, Thomas Wei�chuh wrote:
> > On 2023-07-19 05:10:48+0800, Zhangjin Wu wrote:
> > > diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h
> > > new file mode 100644
> > > index 000000000000..100ec0f412dc
> > > --- /dev/null
> > > +++ b/tools/include/nolibc/arch-powerpc.h
> > > @@ -0,0 +1,156 @@
> > > +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
> > > +/*
> > > + * PowerPC specific definitions for NOLIBC
> > > + * Copyright (C) 2023 Zhangjin Wu <falcon@xxxxxxxxxxx>
> >
> > If it is taken from musl, shouldn't there also be a musl copyright?
>
> In fact it depends. If code was taken there, not only the copyright is
> needed, but the license' compatibility must be verified. If, however,
> the code was only disassembled to be understood and reimplemented (as
> it seems to me), then no code was taken there and it's not needed.
>
This discussion does inspire me a lot to shrink the whole architecture
specific nolibc my_syscall<N>() macros, like crt.h, a common syscall.h
is added to do so. I have finished most of them except the ones passing
arguments via stack, still trying to merge these ones.
With this new syscall.h, to support my_syscall<N>, the arch-<ARCH>.h
will only require to add ~10 lines to define their own syscall
instructions, registers and clobberlist, which looks like this (for
powerpc):
#define _NOLIBC_SYSCALL_CALL "sc; bns+ 1f; neg %0, %0; 1:"
/* PowerPC doesn't always restore r3-r12 for us */
#define _NOLIBC_SYSCALL_CLOBBERLIST
"memory", "cr0", "r12", "r11", "r10", "r9", "r8", "r7", "r6", "r5", "r4"
/* PowerPC write GPRS in kernel side but not restore them */
#define _NOLIBC_GPRS_AS_OUTPUT_OPERANDS
#define _NOLIBC_REG_NUM "r0"
#define _NOLIBC_REG_RET "r3"
#define _NOLIBC_REG_arg1 "r3"
#define _NOLIBC_REG_arg2 "r4"
#define _NOLIBC_REG_arg3 "r5"
#define _NOLIBC_REG_arg4 "r6"
#define _NOLIBC_REG_arg5 "r7"
#define _NOLIBC_REG_arg6 "r8"
Before:
$ ls tools/include/nolibc/arch-*.h | while read f; do git show dfef4fc45d5713eb23d87f0863aff9c33bd4bfaf:$f 2>/dev/null | wc -l | tr -d '\n'; echo " $f"; done
157 tools/include/nolibc/arch-aarch64.h
199 tools/include/nolibc/arch-arm.h
178 tools/include/nolibc/arch-i386.h
164 tools/include/nolibc/arch-loongarch.h
195 tools/include/nolibc/arch-mips.h
0 tools/include/nolibc/arch-powerpc.h
160 tools/include/nolibc/arch-riscv.h
186 tools/include/nolibc/arch-s390.h
176 tools/include/nolibc/arch-x86_64.h
After:
$ wc -l tools/include/nolibc/arch-*.h
54 tools/include/nolibc/arch-aarch64.h
84 tools/include/nolibc/arch-arm.h
90 tools/include/nolibc/arch-i386.h /* the last one use stack to pass arguments, reserve as-is */
59 tools/include/nolibc/arch-loongarch.h
120 tools/include/nolibc/arch-mips.h /* the last two use stack to pass arguments, reserve as-is */
73 tools/include/nolibc/arch-powerpc.h
58 tools/include/nolibc/arch-riscv.h
87 tools/include/nolibc/arch-s390.h
67 tools/include/nolibc/arch-x86_64.h
syscall.h itself:
$ wc -l tools/include/nolibc/syscall.h
112 tools/include/nolibc/syscall.h
Willy, do we need to rename my_syscall<N> to _nolibc_syscall<N> to limit
these macros nolibc internally? I plan to rename all of the new adding
macros with _nolibc_ (for funcs) or _NOLIBC_ (for variables).
Thomas, do we need to merge the syscall macros from unistd.h to this new
syscall.h? we do reuse the macros between them, like the _syscall_narg* ones.
Since this new syscall.h does help a lot to shrink the arch-powerpc.h, I plan
to send this syscall.h at first and then renew our powerpc patchset, what's
your idea?
Thanks,
Zhangjin
> Thanks,
> Willy
