csky: port to uclibc-ng

Follow the steps to build c-sky uclibc linux system:
1. git clone https://github.com/c-sky/buildroot.git
2. cd buildroot
3. make qemu_csky_ck810_uclibc_defconfig
4. make

Follow the buildroot/board/qemu/csky/readme.txt to run.

This buildroot toolchain is pre-build, But you can rebuild
the c-sky uclibc-ng alone and install it to the buildroot
sysroot manually.

We'll try our best to improve the uclibc-ng continuously.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/csky/bits/fenv.h b/libc/sysdeps/linux/csky/bits/fenv.h
new file mode 100644
index 000000000..606fe793d
--- /dev/null
+++ b/libc/sysdeps/linux/csky/bits/fenv.h
@@ -0,0 +1,58 @@
+#ifndef _FENV_H
+# error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
+#endif
+
+/* Define bits representing the exception.  We use the bit positions of
+   the appropriate bits in the FPSR Accrued Exception Byte.  */
+enum
+  {
+    FE_INEXACT = 1 << 3,
+#define FE_INEXACT	FE_INEXACT
+    FE_DIVBYZERO = 1 << 4,
+#define FE_DIVBYZERO	FE_DIVBYZERO
+    FE_UNDERFLOW = 1 << 5,
+#define FE_UNDERFLOW	FE_UNDERFLOW
+    FE_OVERFLOW = 1 << 6,
+#define FE_OVERFLOW	FE_OVERFLOW
+    FE_INVALID = 1 << 7
+#define FE_INVALID	FE_INVALID
+  };
+
+#define FE_ALL_EXCEPT \
+	(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
+
+/* The csky FPU supports all of the four defined rounding modes.  We use
+   the bit positions in the FPCR Mode Control Byte as the values for the
+   appropriate macros.  */
+enum
+  {
+    FE_TONEAREST = 0,
+#define FE_TONEAREST	FE_TONEAREST
+    FE_TOWARDZERO = 1 << 4,
+#define FE_TOWARDZERO	FE_TOWARDZERO
+    FE_DOWNWARD = 2 << 4,
+#define FE_DOWNWARD	FE_DOWNWARD
+    FE_UPWARD = 3 << 4
+#define FE_UPWARD	FE_UPWARD
+  };
+
+/* Type representing exception flags.  */
+typedef unsigned int fexcept_t;
+
+/* Type representing floating-point environment.  This structure
+   corresponds to the layout of the block written by `fmovem'.  */
+typedef struct
+  {
+    unsigned int __control_register;
+    unsigned int __status_register;
+    unsigned int __instruction_address;
+  }
+fenv_t;
+
+/* If the default argument is used we use this value.  */
+#define FE_DFL_ENV	((__const fenv_t *) -1)
+
+#ifdef __USE_GNU
+/* Floating-point environment where none of the exceptions are masked.  */
+# define FE_NOMASK_ENV	((__const fenv_t *) -2)
+#endif