usr: libc: Add libc syscall interface

Signed-off-by: Ian Moffett <ian@osmora.org>

6 files changed, 135 insertions, 16 deletions

diff --git a/.gitignore b/.gitignore
index 844ddb4..22ecedb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@
 /src/sys/target
 /src/sys/os/amd64
 /src/iso_root
+/src/lib/libc/include/sys/
 *.o
 *.d
 *.iso
diff --git a/src/data/build/user.mk b/src/data/build/user.mk
index dd1eb16..ad6b023 100644
--- a/src/data/build/user.mk
+++ b/src/data/build/user.mk
@@ -1,2 +1,3 @@
 INTERNAL_CFLAGS = -T$(LDSCRIPT) -znoexecstack \
-				  -L$(LIBC_DIR) -I$(LIBC_DIR)/include/ -pie -no-pie
+				  -L$(LIBC_DIR) -I$(LIBC_DIR)/include/ \
+				  -I$(LIBC_DIR)/$(TARGET)/include/ -pie -no-pie
diff --git a/src/lib/libc/Makefile b/src/lib/libc/Makefile
index 3287084..adde835 100644
--- a/src/lib/libc/Makefile
+++ b/src/lib/libc/Makefile
@@ -2,13 +2,18 @@ OBJ = $(shell find build/ -name "*.o")
 LIBC_OUT = libc.a
 
 .PHONY: all
-all: build target
+all: build sys target
 	ar rcs $(LIBC_OUT) $(OBJ)
 
 .PHONY: target
 target:
 	cd $(TARGET); make CC=$(CC) LD=$(LD) AS=$(AS)
 
+.PHONY: sys
+sys:
+	mkdir -p include/sys/
+	rsync -av ../../sys/include/sys/ include/sys/
+
 # Create build directory
 build:
 	mkdir -p $@
diff --git a/src/lib/libc/amd64/include/machine/syscall.h b/src/lib/libc/amd64/include/machine/syscall.h
new file mode 100644
index 0000000..d089ba0
--- /dev/null
+++ b/src/lib/libc/amd64/include/machine/syscall.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MACHINE_SYSCALL_H_
+#define _MACHINE_SYSCALL_H_
+
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/cdefs.h>
+
+typedef __ssize_t scarg_t;
+
+__always_inline static inline long
+syscall0(scarg_t code)
+{
+    volatile long ret;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code));
+    return ret;
+}
+
+__always_inline static inline long
+syscall1(scarg_t code, scarg_t arg0)
+{
+    volatile long ret;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code), "D"(arg0) : "memory");
+    return ret;
+}
+
+__always_inline static long inline
+syscall2(scarg_t code, scarg_t arg0, scarg_t arg1)
+{
+    volatile long ret;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code), "D"(arg0), "S"(arg1) : "memory");
+    return ret;
+}
+
+__always_inline static inline long
+syscall3(scarg_t code, scarg_t arg0, scarg_t arg1, scarg_t arg2)
+{
+    volatile long ret;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code), "D"(arg0), "S"(arg1), "d"(arg2) : "memory");
+    return ret;
+}
+
+__always_inline static inline long
+syscall4(scarg_t code, scarg_t arg0, scarg_t arg1, scarg_t arg2, scarg_t arg3)
+{
+    volatile long ret;
+    register scarg_t _arg3 asm("r10") = arg3;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code), "D"(arg0), "S"(arg1), "d"(arg2), "r"(_arg3) : "memory");
+    return ret;
+}
+
+__always_inline static inline long
+syscall5(scarg_t code, scarg_t arg0, scarg_t arg1, scarg_t arg2, scarg_t arg3, scarg_t arg4)
+{
+    volatile long ret;
+    register scarg_t _arg3 asm("r10") = arg3;
+    register scarg_t _arg4 asm("r9") = arg4;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code), "D"(arg0), "S"(arg1), "d"(arg2), "r"(_arg3), "r"(_arg4) : "memory");
+    return ret;
+}
+
+__always_inline static inline long
+syscall6(scarg_t code, scarg_t arg0, scarg_t arg1, scarg_t arg2, scarg_t arg3, scarg_t arg4, scarg_t arg5)
+{
+    volatile long ret;
+    register scarg_t _arg3 asm("r10") = arg3;
+    register scarg_t _arg4 asm("r9") = arg4;
+    register scarg_t _arg5 asm("r8") = arg5;
+    __ASMV("int $0x80" : "=a"(ret) : "a"(code), "D"(arg0), "S"(arg1), "d"(arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) : "memory");
+    return ret;
+}
+
+#define _SYSCALL_N(a0, a1, a2, a3, a4, a5, a6, name, ...) \
+    name
+
+#define syscall(...) \
+_SYSCALL_N(__VA_ARGS__, syscall6, syscall5, \
+            syscall4, syscall3, syscall2, syscall1, \
+            syscall0)(__VA_ARGS__)
+
+#endif  /* !_MACHINE_SYSCALL_H_ */
diff --git a/src/sys/include/compat/unix/syscall.h b/src/sys/include/compat/unix/syscall.h
index a3e7257..88c86ba 100644
--- a/src/sys/include/compat/unix/syscall.h
+++ b/src/sys/include/compat/unix/syscall.h
@@ -35,17 +35,6 @@
 #include <sys/syscall.h>
 
 /*
- * Default syscall numbers
- *
- * Defines marked as (mandatory) must be implemented
- * between latches.
- */
-#define SYS_none    0x00
-#define SYS_exit    0x01
-#define SYS_write   0x02
-#define SYS_cross   0x03    /* cross a border (mandatory) */
-
-/*
  * Exit the current process - exit(2) syscall
  */
 scret_t sys_exit(struct syscall_args *scargs);
diff --git a/src/sys/include/sys/syscall.h b/src/sys/include/sys/syscall.h
index 9d9c765..3f8ab10 100644
--- a/src/sys/include/sys/syscall.h
+++ b/src/sys/include/sys/syscall.h
@@ -32,6 +32,23 @@
 
 #include <sys/types.h>
 #include <sys/limits.h>
+#if !defined(_KERNEL)
+#include <machine/syscall.h>
+#endif  /* _!KERNEL */
+
+/*
+ * Default syscall numbers
+ *
+ * Defines marked as (mandatory) must be implemented
+ * between latches.
+ */
+#define SYS_none    0x00
+#define SYS_exit    0x01
+#define SYS_write   0x02
+#define SYS_cross   0x03    /* cross a border (mandatory) */
+
+typedef __ssize_t scret_t;
+typedef __ssize_t scarg_t;
 
 #if defined(_KERNEL)
 /*
@@ -39,9 +56,6 @@
  */
 #define SCARG(SCARGS, TYPE, SYSNO) ((TYPE)(SCARGS)->arg[(SYSNO)])
 
-typedef ssize_t scret_t;
-typedef ssize_t scarg_t;
-
 struct syscall_args {
     scarg_t arg[6];
     struct trapframe *tf;