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-rw-r--r--tools/include/nolibc/nolibc.h194
1 files changed, 194 insertions, 0 deletions
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index 1708e9f9f8aa..2551e9b71167 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -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