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Merge tag 'nolibc-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kern…
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…el/git/wtarreau/nolibc

Pull RISC-V nolibc header update from Willy Tarreau:
 "This single commit adds support for the RISCV architecture to the
  nolibc header file. Currently the file is only used by rcutorture but
  Pranith Kumar who contributed it would like to have this work merged.

  I only did some trivial tests to verify that it does not break x86,
  which I consider sufficient since all the code is cleanly enclosed
  inside a single #if/endif block"

* tag 'nolibc-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc:
  tool headers nolibc: add RISCV support
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@torvalds
torvalds committed May 8, 2019
2 parents ce45327 + 582e84f commit 019d731
Showing 1 changed file with 194 additions and 0 deletions.
194 changes: 194 additions & 0 deletions tools/include/nolibc/nolibc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1243,6 +1243,200 @@ struct sys_stat_struct {
long st_pad4[14];
};

#elif defined(__riscv)

#if __riscv_xlen == 64
#define PTRLOG "3"
#define SZREG "8"
#elif __riscv_xlen == 32
#define PTRLOG "2"
#define SZREG "4"
#endif

/* Syscalls for RISCV :
* - stack is 16-byte aligned
* - syscall number is passed in a7
* - arguments are in a0, a1, a2, a3, a4, a5
* - the system call is performed by calling ecall
* - syscall return comes in a0
* - the arguments are cast to long and assigned into the target
* registers which are then simply passed as registers to the asm code,
* so that we don't have to experience issues with register constraints.
*/

#define my_syscall0(num) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0"); \
\
asm volatile ( \
"ecall\n\t" \
: "=r"(_arg1) \
: "r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

#define my_syscall1(num, arg1) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0") = (long)(arg1); \
\
asm volatile ( \
"ecall\n" \
: "+r"(_arg1) \
: "r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

#define my_syscall2(num, arg1, arg2) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0") = (long)(arg1); \
register long _arg2 asm("a1") = (long)(arg2); \
\
asm volatile ( \
"ecall\n" \
: "+r"(_arg1) \
: "r"(_arg2), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

#define my_syscall3(num, arg1, arg2, arg3) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0") = (long)(arg1); \
register long _arg2 asm("a1") = (long)(arg2); \
register long _arg3 asm("a2") = (long)(arg3); \
\
asm volatile ( \
"ecall\n\t" \
: "+r"(_arg1) \
: "r"(_arg2), "r"(_arg3), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0") = (long)(arg1); \
register long _arg2 asm("a1") = (long)(arg2); \
register long _arg3 asm("a2") = (long)(arg3); \
register long _arg4 asm("a3") = (long)(arg4); \
\
asm volatile ( \
"ecall\n" \
: "+r"(_arg1) \
: "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0") = (long)(arg1); \
register long _arg2 asm("a1") = (long)(arg2); \
register long _arg3 asm("a2") = (long)(arg3); \
register long _arg4 asm("a3") = (long)(arg4); \
register long _arg5 asm("a4") = (long)(arg5); \
\
asm volatile ( \
"ecall\n" \
: "+r"(_arg1) \
: "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
register long _num asm("a7") = (num); \
register long _arg1 asm("a0") = (long)(arg1); \
register long _arg2 asm("a1") = (long)(arg2); \
register long _arg3 asm("a2") = (long)(arg3); \
register long _arg4 asm("a3") = (long)(arg4); \
register long _arg5 asm("a4") = (long)(arg5); \
register long _arg6 asm("a5") = (long)(arg6); \
\
asm volatile ( \
"ecall\n" \
: "+r"(_arg1) \
: "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), "r"(_arg6), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})

/* startup code */
asm(".section .text\n"
".global _start\n"
"_start:\n"
".option push\n"
".option norelax\n"
"lla gp, __global_pointer$\n"
".option pop\n"
"ld a0, 0(sp)\n" // argc (a0) was in the stack
"add a1, sp, "SZREG"\n" // argv (a1) = sp
"slli a2, a0, "PTRLOG"\n" // envp (a2) = SZREG*argc ...
"add a2, a2, "SZREG"\n" // + SZREG (skip null)
"add a2,a2,a1\n" // + argv
"andi sp,a1,-16\n" // sp must be 16-byte aligned
"call main\n" // main() returns the status code, we'll exit with it.
"andi a0, a0, 0xff\n" // limit exit code to 8 bits
"li a7, 93\n" // NR_exit == 93
"ecall\n"
"");

/* fcntl / open */
#define O_RDONLY 0
#define O_WRONLY 1
#define O_RDWR 2
#define O_CREAT 0x100
#define O_EXCL 0x200
#define O_NOCTTY 0x400
#define O_TRUNC 0x1000
#define O_APPEND 0x2000
#define O_NONBLOCK 0x4000
#define O_DIRECTORY 0x200000

struct sys_stat_struct {
unsigned long st_dev; /* Device. */
unsigned long st_ino; /* File serial number. */
unsigned int st_mode; /* File mode. */
unsigned int st_nlink; /* Link count. */
unsigned int st_uid; /* User ID of the file's owner. */
unsigned int st_gid; /* Group ID of the file's group. */
unsigned long st_rdev; /* Device number, if device. */
unsigned long __pad1;
long st_size; /* Size of file, in bytes. */
int st_blksize; /* Optimal block size for I/O. */
int __pad2;
long st_blocks; /* Number 512-byte blocks allocated. */
long st_atime; /* Time of last access. */
unsigned long st_atime_nsec;
long st_mtime; /* Time of last modification. */
unsigned long st_mtime_nsec;
long st_ctime; /* Time of last status change. */
unsigned long st_ctime_nsec;
unsigned int __unused4;
unsigned int __unused5;
};

#endif


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