From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/13323 Path: news.gmane.org!.POSTED!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: riscv port for review Date: Thu, 27 Sep 2018 22:46:33 -0400 Message-ID: <20180928024633.GR17995@brightrain.aerifal.cx> References: <20180928022404.GQ17995@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1538102682 29651 195.159.176.226 (28 Sep 2018 02:44:42 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 28 Sep 2018 02:44:42 +0000 (UTC) User-Agent: Mutt/1.5.21 (2010-09-15) To: musl@lists.openwall.com Original-X-From: musl-return-13339-gllmg-musl=m.gmane.org@lists.openwall.com Fri Sep 28 04:44:38 2018 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1g5ili-0007dO-44 for gllmg-musl@m.gmane.org; Fri, 28 Sep 2018 04:44:38 +0200 Original-Received: (qmail 1176 invoked by uid 550); 28 Sep 2018 02:46:46 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 1153 invoked from network); 28 Sep 2018 02:46:45 -0000 Content-Disposition: inline In-Reply-To: <20180928022404.GQ17995@brightrain.aerifal.cx> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:13323 Archived-At: On Thu, Sep 27, 2018 at 10:24:04PM -0400, Rich Felker wrote: > Pulled from here: > https://github.com/riscv/riscv-musl/commit/6a4f4a9c774608add4b02f95322518bd2f5f51ee > > Attached for review. Review inline below: > diff --git a/arch/riscv32/atomic_arch.h b/arch/riscv32/atomic_arch.h > new file mode 100644 > index 0000000..93c89cc > --- /dev/null > +++ b/arch/riscv32/atomic_arch.h > @@ -0,0 +1,35 @@ > +#define a_barrier a_barrier > +static inline void a_barrier() > +{ > + __asm__ __volatile__ ("fence rw,rw" : : : "memory"); > +} > + > +#define a_ll a_ll > +static inline int a_ll(volatile int *p) > +{ > + int v; > + __asm__ __volatile__ ("lr.w %0, (%1)" : "=&r"(v) : "r"(p)); > + return v; > +} > + > +#define a_sc a_sc > +static inline int a_sc(volatile int *p, int v) > +{ > + int r; > + __asm__ __volatile__ ("sc.w %0, %2, (%1)" : "=&r"(r) : "r"(p), "r"(v) : "memory"); > + return !r; > +} > + > +#define a_cas a_cas > +static inline int a_cas(volatile int *p, int t, int s) > +{ > + int old, tmp; > + __asm__("1: lr.w %0, %2 \n" > + " bne %0, %3, 1f \n" > + " sc.w %1, %4, %2 \n" > + " bnez %1, 1b \n" > + "1: \n" > + : "=&r"(old), "+r"(tmp), "+A"(*p) > + : "r"(t), "r"(s)); > + return old; > +} Why are both a_ll/a_sc and a_cas defined, and why is a_cas missing barriers? Normally if a_ll/a_sc/a_barrier are defined, the top-level atomic.h should be allowed to generate a_cas in terms of them. > diff --git a/arch/riscv32/bits/signal.h b/arch/riscv32/bits/signal.h > new file mode 100644 > index 0000000..8b992cc > --- /dev/null > +++ b/arch/riscv32/bits/signal.h > @@ -0,0 +1,113 @@ > +#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \ > + || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE) > + > +#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE) > +# define MINSIGSTKSZ 2048 > +# define SIGSTKSZ 8192 > +#endif > + > +/* gregs[0] holds the program counter. */ > + > +#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) > +typedef unsigned long greg_t; > +typedef unsigned long gregset_t[32]; > + > +struct __riscv_f_ext_state { > + unsigned int f[32]; > + unsigned int fcsr; > +}; > + > +struct __riscv_d_ext_state { > + unsigned long long f[32]; > + unsigned int fcsr; > +}; > + > +struct __riscv_q_ext_state { > + unsigned long long f[64] __attribute__((aligned(16))); > + unsigned int fcsr; > + unsigned int reserved[3]; > +}; > + > +union __riscv_fp_state { > + struct __riscv_f_ext_state f; > + struct __riscv_d_ext_state d; > + struct __riscv_q_ext_state q; > +}; > + > +typedef union __riscv_fp_state fpregset_t; > + > +typedef struct sigcontext { > + gregset_t gregs; > + fpregset_t fpregs; > +} mcontext_t; > + > +#else > +typedef struct { > + unsigned long gregs[32]; > + unsigned long long fpregs[66]; > +} mcontext_t; > +#endif In the namespace-safe version of mcontext_t, the names gregs and fpregs are not valid here. They would need to be __-prefixed or in some other reserved namespace. > +struct sigaltstack { > + void *ss_sp; > + int ss_flags; > + size_t ss_size; > +}; > + > +typedef struct __ucontext > +{ > + unsigned long uc_flags; > + struct __ucontext *uc_link; > + stack_t uc_stack; > + sigset_t uc_sigmask; > + char __unused[1024 / 8 - sizeof(sigset_t)]; This is an invalid array of size zero and should just be removed. > + mcontext_t uc_mcontext; > +} ucontext_t; ... > diff --git a/arch/riscv32/crt_arch.h b/arch/riscv32/crt_arch.h > new file mode 100644 > index 0000000..65187e1 > --- /dev/null > +++ b/arch/riscv32/crt_arch.h > @@ -0,0 +1,18 @@ > +__asm__( > +".text\n" > +".global " START "\n" > +".type " START ",%function\n" > +START ":\n" > +".weak __global_pointer$\n" > +".hidden __global_pointer$\n\t" > +".option push\n" > +".option norelax\n\t" > +"lla gp, __global_pointer$\n" > +".option pop\n\t" > +"mv a0, sp\n" > +".weak _DYNAMIC\n" > +".hidden _DYNAMIC\n\t" > +"lla a1, _DYNAMIC\n\t" > +"andi sp, sp, -16\n\t" > +"jal " START "_c" > +); > diff --git a/arch/riscv32/pthread_arch.h b/arch/riscv32/pthread_arch.h > new file mode 100644 > index 0000000..feffaa4 > --- /dev/null > +++ b/arch/riscv32/pthread_arch.h > @@ -0,0 +1,12 @@ > +static inline struct pthread *__pthread_self() > +{ > + char *tp; > + __asm__ __volatile__("mv %0, tp" : "=r"(tp)); > + return (void *)(tp - sizeof(struct pthread)); > +} > + > +#define TLS_ABOVE_TP > +#define GAP_ABOVE_TP 0 > +#define TP_ADJ(p) ((char *)p + sizeof(struct pthread)) > + > +#define MC_PC gregs[0] > diff --git a/arch/riscv32/reloc.h b/arch/riscv32/reloc.h > new file mode 100644 > index 0000000..d057bbe > --- /dev/null > +++ b/arch/riscv32/reloc.h > @@ -0,0 +1,27 @@ > +#if defined __riscv_float_abi_soft > +#define RISCV_FP_SUFFIX "-sf" > +#elif defined __riscv_float_abi_single > +#define RISCV_FP_SUFFIX "-sp" > +#elif defined __riscv_float_abi_double > +#define RISCV_FP_SUFFIX "" > +#endif > + > +#define RISCV_LDSO_HELPER(x) "riscv" #x > +#define RISCV_LDSO(x) RISCV_LDSO_HELPER(x) > + > +#define LDSO_ARCH RISCV_LDSO(__riscv_xlen) RISCV_FP_SUFFIX Elsewhere it looks like little/big endian are both options, but I see no endian variant here. If so this needs to be fixed. Also what is __riscv_xlen? A predefined macro that expands to 32 or 64? Since this file is just for 32-bit it should just be hard-coded rather than assuming a macro would expand to the token 32 and not (31+1) or some other expression equal to 32, I think. > diff --git a/arch/riscv32/syscall_arch.h b/arch/riscv32/syscall_arch.h > new file mode 100644 > index 0000000..bc60d1f > --- /dev/null > +++ b/arch/riscv32/syscall_arch.h > @@ -0,0 +1,78 @@ > +#define __SYSCALL_LL_E(x) \ > +((union { long long ll; long l[2]; }){ .ll = x }).l[0], \ > +((union { long long ll; long l[2]; }){ .ll = x }).l[1] > +#define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x)) > + > +#define __asm_syscall(...) \ > + __asm__ __volatile__ ("scall\n\t" \ > + : "+r"(a0) : __VA_ARGS__ : "memory"); \ > + return a0; \ > + > +static inline long __syscall0(long n) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0"); > + __asm_syscall("r"(a7)) > +} > + > +static inline long __syscall1(long n, long a) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0") = a; > + __asm_syscall("r"(a7), "0"(a0)) > +} > + > +static inline long __syscall2(long n, long a, long b) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0") = a; > + register long a1 __asm__("a1") = b; > + __asm_syscall("r"(a7), "0"(a0), "r"(a1)) > +} > + > +static inline long __syscall3(long n, long a, long b, long c) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0") = a; > + register long a1 __asm__("a1") = b; > + register long a2 __asm__("a2") = c; > + __asm_syscall("r"(a7), "0"(a0), "r"(a1), "r"(a2)) > +} > + > +static inline long __syscall4(long n, long a, long b, long c, long d) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0") = a; > + register long a1 __asm__("a1") = b; > + register long a2 __asm__("a2") = c; > + register long a3 __asm__("a3") = d; > + __asm_syscall("r"(a7), "0"(a0), "r"(a1), "r"(a2), "r"(a3)) > +} > + > +static inline long __syscall5(long n, long a, long b, long c, long d, long e) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0") = a; > + register long a1 __asm__("a1") = b; > + register long a2 __asm__("a2") = c; > + register long a3 __asm__("a3") = d; > + register long a4 __asm__("a4") = e; > + __asm_syscall("r"(a7), "0"(a0), "r"(a1), "r"(a2), "r"(a3), "r"(a4)) > +} > + > +static inline long __syscall6(long n, long a, long b, long c, long d, long e, long f) > +{ > + register long a7 __asm__("a7") = n; > + register long a0 __asm__("a0") = a; > + register long a1 __asm__("a1") = b; > + register long a2 __asm__("a2") = c; > + register long a3 __asm__("a3") = d; > + register long a4 __asm__("a4") = e; > + register long a5 __asm__("a5") = f; > + __asm_syscall("r"(a7), "0"(a0), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5)) > +} > + > +#define VDSO_USEFUL > +/* We don't have a clock_gettime function. > +#define VDSO_CGT_SYM "__vdso_clock_gettime" > +#define VDSO_CGT_VER "LINUX_2.6" */ In that case VDSO_USEFUL might as well also be omitted for now. > diff --git a/arch/riscv64/atomic_arch.h b/arch/riscv64/atomic_arch.h > new file mode 100644 > index 0000000..018c7fd > --- /dev/null > +++ b/arch/riscv64/atomic_arch.h > @@ -0,0 +1,66 @@ > +#define a_barrier a_barrier > +static inline void a_barrier() > +{ > + __asm__ __volatile__ ("fence rw,rw" : : : "memory"); > +} > + > +#define a_ll a_ll > +static inline int a_ll(volatile int *p) > +{ > + int v; > + __asm__ __volatile__ ("lr.w %0, %1" : "=&r"(v), "+A"(*p)); > + return v; > +} > + > +#define a_sc a_sc > +static inline int a_sc(volatile int *p, int v) > +{ > + int r; > + __asm__ __volatile__ ("sc.w %0, %2, %1" : "=&r"(r), "+A"(*p) : "r"(v) : "memory"); > +return !r; > +} > + > +#define a_cas a_cas > +static inline int a_cas(volatile int *p, int t, int s) > +{ > + int old, tmp; > + __asm__("1: lr.w %0, %2 \n" > + " bne %0, %3, 1f \n" > + " sc.w %1, %4, %2 \n" > + " bnez %1, 1b \n" > + "1: \n" > + : "=&r"(old), "+r"(tmp), "+A"(*p) > + : "r"(t), "r"(s)); > + return old; > +} > + > +#define a_ll_p a_ll_p > +static inline void *a_ll_p(volatile void *p) > +{ > + void *v; > + __asm__ __volatile__ ("lr.d %0, %1" : "=&r"(v), "+A"(*(long *)p)); > + return v; > +} > + > +#define a_sc_p a_sc_p > +static inline int a_sc_p(volatile int *p, void *v) > +{ > + int r; > + __asm__ __volatile__ ("sc.d %0, %2, %1" : "=&r"(r), "+A"(*(long *)p) : "r"(v) : "memory"); > + return !r; > +} > + > +#define a_cas_p a_cas_p > +static inline void *a_cas_p(volatile void *p, void *t, void *s) > +{ > + void *old; > + int tmp; > + __asm__("1: lr.d %0, %2 \n" > + " bne %0, %3, 1f \n" > + " sc.d %1, %4, %2 \n" > + " bnez %1, 1b \n" > + "1: \n" > + : "=&r"(old), "+r"(tmp), "+A"(*(long *)p) > + : "r"(t), "r"(s)); > + return old; > +} Same comments about cas vs ll/sc, and lack of barrier, as 32-bit version. > diff --git a/arch/riscv64/bits/signal.h b/arch/riscv64/bits/signal.h > new file mode 100644 > index 0000000..8b992cc > --- /dev/null > +++ b/arch/riscv64/bits/signal.h > @@ -0,0 +1,113 @@ > +#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \ > + || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE) > + > +#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE) > +# define MINSIGSTKSZ 2048 > +# define SIGSTKSZ 8192 > +#endif > + > +/* gregs[0] holds the program counter. */ > + > +#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) > +typedef unsigned long greg_t; > +typedef unsigned long gregset_t[32]; > + > +struct __riscv_f_ext_state { > + unsigned int f[32]; > + unsigned int fcsr; > +}; > + > +struct __riscv_d_ext_state { > + unsigned long long f[32]; > + unsigned int fcsr; > +}; > + > +struct __riscv_q_ext_state { > + unsigned long long f[64] __attribute__((aligned(16))); > + unsigned int fcsr; > + unsigned int reserved[3]; > +}; > + > +union __riscv_fp_state { > + struct __riscv_f_ext_state f; > + struct __riscv_d_ext_state d; > + struct __riscv_q_ext_state q; > +}; > + > +typedef union __riscv_fp_state fpregset_t; > + > +typedef struct sigcontext { > + gregset_t gregs; > + fpregset_t fpregs; > +} mcontext_t; > + > +#else > +typedef struct { > + unsigned long gregs[32]; > + unsigned long long fpregs[66]; > +} mcontext_t; > +#endif > + > +struct sigaltstack { > + void *ss_sp; > + int ss_flags; > + size_t ss_size; > +}; > + > +typedef struct __ucontext > +{ > + unsigned long uc_flags; > + struct __ucontext *uc_link; > + stack_t uc_stack; > + sigset_t uc_sigmask; > + char __unused[1024 / 8 - sizeof(sigset_t)]; > + mcontext_t uc_mcontext; > +} ucontext_t; Same issues here as 32-bit. > diff --git a/arch/riscv64/reloc.h b/arch/riscv64/reloc.h > new file mode 100644 > index 0000000..8bd90dd > --- /dev/null > +++ b/arch/riscv64/reloc.h > @@ -0,0 +1,27 @@ > +#if defined __riscv_float_abi_soft > +#define RISCV_FP_SUFFIX "-sf" > +#elif defined __riscv_float_abi_single > +#define RISCV_FP_SUFFIX "-sp" > +#elif defined __riscv_float_abi_double > +#define RISCV_FP_SUFFIX "" > +#endif > + > +#define RISCV_LDSO_HELPER(x) "riscv" #x > +#define RISCV_LDSO(x) RISCV_LDSO_HELPER(x) > + > +#define LDSO_ARCH RISCV_LDSO(__riscv_xlen) RISCV_FP_SUFFIX Same here. > diff --git a/configure b/configure > index 997e665..4d3d8b4 100755 > --- a/configure > +++ b/configure > @@ -322,6 +322,8 @@ microblaze*) ARCH=microblaze ;; > or1k*) ARCH=or1k ;; > powerpc64*) ARCH=powerpc64 ;; > powerpc*) ARCH=powerpc ;; > +riscv64*) ARCH=riscv64 ;; > +riscv*) ARCH=riscv32 ;; > sh[1-9bel-]*|sh|superh*) ARCH=sh ;; > s390x*) ARCH=s390x ;; > unknown) fail "$0: unable to detect target arch; try $0 --target=..." ;; > @@ -640,6 +642,11 @@ trycppif __LITTLE_ENDIAN__ "$t" && SUBARCH=${SUBARCH}le > trycppif _SOFT_FLOAT "$t" && fail "$0: error: soft-float not supported on powerpc64" > fi > > +if test "$ARCH" = "riscv" || test "$ARCH" = "riscv64" ; then > +trycppif "RISCVEB || _RISCVEB || __RISCVEB || __RISCVEB__" "$t" && SUBARCH=${SUBARCH}eb Predefined macros that violate the namespace (RISCVEB) shouldn't be defined or observed. > +trycppif __riscv_soft_float "$t" && SUBARCH=${SUBARCH}-sf > +fi > + > if test "$ARCH" = "sh" ; then > tryflag CFLAGS_AUTO -Wa,--isa=any > trycppif __BIG_ENDIAN__ "$t" && SUBARCH=${SUBARCH}eb > diff --git a/crt/riscv32/crti.s b/crt/riscv32/crti.s > new file mode 100644 > index 0000000..6916bfd > --- /dev/null > +++ b/crt/riscv32/crti.s > @@ -0,0 +1,11 @@ > +.section .init > +.global _init > +.type _init,%function > +_init: > + ret > + > +.section .fini > +.global _fini > +.type _fini,%function > +_fini: > + ret > diff --git a/crt/riscv32/crtn.s b/crt/riscv32/crtn.s > new file mode 100644 > index 0000000..e69de29 It looks like these are not used, right? > diff --git a/include/elf.h b/include/elf.h > index c229735..ec2e8fd 100644 > --- a/include/elf.h > +++ b/include/elf.h > @@ -3164,6 +3164,62 @@ enum > #define R_BPF_NONE 0 > #define R_BPF_MAP_FD 1 > > +#define R_RISCV_NONE 0 > +#define R_RISCV_32 1 > +#define R_RISCV_64 2 > +#define R_RISCV_RELATIVE 3 > +#define R_RISCV_COPY 4 > +#define R_RISCV_JUMP_SLOT 5 > +#define R_RISCV_TLS_DTPMOD32 6 > +#define R_RISCV_TLS_DTPMOD64 7 > +#define R_RISCV_TLS_DTPREL32 8 > +#define R_RISCV_TLS_DTPREL64 9 > +#define R_RISCV_TLS_TPREL32 10 > +#define R_RISCV_TLS_TPREL64 11 > + > +#define R_RISCV_BRANCH 16 > +#define R_RISCV_JAL 17 > +#define R_RISCV_CALL 18 > +#define R_RISCV_CALL_PLT 19 > +#define R_RISCV_GOT_HI20 20 > +#define R_RISCV_TLS_GOT_HI20 21 > +#define R_RISCV_TLS_GD_HI20 22 > +#define R_RISCV_PCREL_HI20 23 > +#define R_RISCV_PCREL_LO12_I 24 > +#define R_RISCV_PCREL_LO12_S 25 > +#define R_RISCV_HI20 26 > +#define R_RISCV_LO12_I 27 > +#define R_RISCV_LO12_S 28 > +#define R_RISCV_TPREL_HI20 29 > +#define R_RISCV_TPREL_LO12_I 30 > +#define R_RISCV_TPREL_LO12_S 31 > +#define R_RISCV_TPREL_ADD 32 > +#define R_RISCV_ADD8 33 > +#define R_RISCV_ADD16 34 > +#define R_RISCV_ADD32 35 > +#define R_RISCV_ADD64 36 > +#define R_RISCV_SUB8 37 > +#define R_RISCV_SUB16 38 > +#define R_RISCV_SUB32 39 > +#define R_RISCV_SUB64 40 > +#define R_RISCV_GNU_VTINHERIT 41 > +#define R_RISCV_GNU_VTENTRY 42 > +#define R_RISCV_ALIGN 43 > +#define R_RISCV_RVC_BRANCH 44 > +#define R_RISCV_RVC_JUMP 45 > +#define R_RISCV_RVC_LUI 46 > +#define R_RISCV_GPREL_I 47 > +#define R_RISCV_GPREL_S 48 > +#define R_RISCV_TPREL_I 49 > +#define R_RISCV_TPREL_S 50 > +#define R_RISCV_RELAX 51 > +#define R_RISCV_SUB6 52 > +#define R_RISCV_SET6 53 > +#define R_RISCV_SET8 54 > +#define R_RISCV_SET16 55 > +#define R_RISCV_SET32 56 > +#define R_RISCV_32_PCREL 57 > + > #ifdef __cplusplus > } > #endif This should be its own patch independent of the port; I can commit it earlier. > diff --git a/src/thread/riscv32/syscall_cp.s b/src/thread/riscv32/syscall_cp.s > new file mode 100644 > index 0000000..71bf6d3 > --- /dev/null > +++ b/src/thread/riscv32/syscall_cp.s > @@ -0,0 +1,29 @@ > +.global __cp_begin > +.hidden __cp_begin > +.global __cp_end > +.hidden __cp_end > +.global __cp_cancel > +.hidden __cp_cancel > +.hidden __cancel > +.global __syscall_cp_asm > +.hidden __syscall_cp_asm > +.type __syscall_cp_asm, %function > +__syscall_cp_asm: > +__cp_begin: > + lw t0, 0(a0) > + bnez t0, __cp_cancel > + > + mv t0, a1 > + mv a0, a2 > + mv a1, a3 > + mv a2, a4 > + mv a3, a5 > + mv a4, a6 > + mv a5, a7 > + lw a6, 0(sp) > + mv a7, t0 > + scall > +__cp_cancel: > + ret > +__cp_end: > + j __cancel The labels here are backwards. __cp_end must point immediately after the syscall instruction, and __cp_end needs to jump to __cancel. > diff --git a/src/thread/riscv64/syscall_cp.s b/src/thread/riscv64/syscall_cp.s > new file mode 100644 > index 0000000..c745b32 > --- /dev/null > +++ b/src/thread/riscv64/syscall_cp.s > @@ -0,0 +1,29 @@ > +.global __cp_begin > +.hidden __cp_begin > +.global __cp_end > +.hidden __cp_end > +.global __cp_cancel > +.hidden __cp_cancel > +.hidden __cancel > +.global __syscall_cp_asm > +.hidden __syscall_cp_asm > +.type __syscall_cp_asm, %function > +__syscall_cp_asm: > +__cp_begin: > + ld t0, 0(a0) > + bnez t0, __cp_cancel > + > + mv t0, a1 > + mv a0, a2 > + mv a1, a3 > + mv a2, a4 > + mv a3, a5 > + mv a4, a6 > + mv a5, a7 > + ld a6, 0(sp) > + mv a7, t0 > + scall > +__cp_cancel: > + ret > +__cp_end: > + j __cancel > -- > 2.10.0 > Likewise here. Rich