Basic sysctl infrastructure

sys/SConscript

@@ -51,6 +51,7 @@ src_common = [
     "kern/slab.c",
     "kern/spinlock.c",
     "kern/syscall.c",
+    "kern/sysctl.c",
     "kern/thread.c",
     "kern/vfs.c",
     "dev/ahci.c",

sys/include/sysctl.h

@@ -0,0 +1,57 @@
+
+#ifndef __SYS_SYSCTL_H__
+#define __SYS_SYSCTL_H__
+
+/*
+ * System Control Macros
+ * SYSCTL_STR(PATH, FLAGS, DESCRIPTION, DEFAULT)
+ * SYSCTL_INT(PATH, FLAGS, DESCRIPTION, DEFAULT)
+ * SYSCTL_BOOL(PATH, FLAGS, DESCRIPTION, DEFAULT)
+ * SYSCTL_END()
+ */
+
+#define SYSCTL_FLAG_RO		1
+#define SYSCTL_FLAG_RW		2
+
+#define SYSCTL_LIST \
+    SYSCTL_STR(kern_ostype, SYSCTL_FLAG_RO, "OS Type", "Castor") \
+    SYSCTL_INT(kern_hz, SYSCTL_FLAG_RW, "Tick frequency", 100) \
+    SYSCTL_INT(time_tzadj, SYSCTL_FLAG_RW, "time zone offset in seconds", 0) \
+
+#define SYSCTL_STR_MAXLENGTH	128
+
+typedef struct SysCtlString {
+    char	path[64];
+    char	value[SYSCTL_STR_MAXLENGTH];
+} SysCtlString;
+
+typedef struct SysCtlInt {
+    char	path[64];
+    int64_t	value;
+} SysCtlInt;
+
+typedef struct SysCtlBool {
+    char	path[64];
+    bool	value;
+} SysCtlBool;
+
+#define SYSCTL_STR(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+extern SysCtlString SYSCTL_##_PATH;
+#define SYSCTL_INT(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+extern SysCtlInt SYSCTL_##_PATH;
+#define SYSCTL_BOOL(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+extern SysCtlBool SYSCTL_##_PATH;
+SYSCTL_LIST
+#undef SYSCTL_STR
+#undef SYSCTL_INT
+#undef SYSCTL_BOOL
+
+#define SYSCTL_GETSTR(_PATH) SYSCTL_##_PATH.value
+#define SYSCTL_SETSTR(_PATH, _VALUE) strncpy(SYSCTL_##_PATH.value, _VALUE, SYSCTL_STR_MAXLENGTH);
+#define SYSCTL_GETINT(_PATH) SYSCTL_##_PATH.value
+#define SYSCTL_SETINT(_PATH, _VALUE) SYSCTL_##_PATH.value = _VALUE
+#define SYSCTL_GETBOOL(_PATH) SYSCTL_##_PATH.value
+#define SYSCTL_SETBOOL(_PATH, _VALUE) SYSCTL_##_PATH.value = _VALUE
+
+#endif /* __SYS_SYSCTL_H__ */
+

sys/kern/sysctl.c

@@ -0,0 +1,104 @@
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <sys/kassert.h>
+#include <sys/kdebug.h>
+#include <sys/sysctl.h>
+
+#define SYSCTL_TYPE_STR		1
+#define SYSCTL_TYPE_INT		2
+#define SYSCTL_TYPE_BOOL	3
+
+typedef struct SysCtlEntry {
+    char	path[64];
+    int		type;
+    int		flags;
+    char	description[128];
+    void	*node;
+} SysCtlEntry;
+
+#define SYSCTL_STR(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+    { #_PATH, SYSCTL_TYPE_STR, _FLAGS, _DESCRIPTION, &SYSCTL_##_PATH },
+#define SYSCTL_INT(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+    { #_PATH, SYSCTL_TYPE_INT, _FLAGS, _DESCRIPTION, &SYSCTL_##_PATH },
+#define SYSCTL_BOOL(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+    { #_PATH, SYSCTL_TYPE_BOOL, _FLAGS, _DESCRIPTION, &SYSCTL_##_PATH },
+SysCtlEntry SYSCTLTable[] = {
+    SYSCTL_LIST
+    { "", 0, 0, "", NULL },
+};
+#undef SYSCTL_STR
+#undef SYSCTL_INT
+#undef SYSCTL_BOOL
+
+#define SYSCTL_STR(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+SysCtlString SYSCTL_##_PATH = { #_PATH, _DEFAULT };
+#define SYSCTL_INT(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+SysCtlInt SYSCTL_##_PATH = { #_PATH, _DEFAULT };
+#define SYSCTL_BOOL(_PATH, _FLAGS, _DESCRIPTION, _DEFAULT) \
+SysCtlBool SYSCTL_##_PATH = { #_PATH, _DEFAULT };
+SYSCTL_LIST
+#undef SYSCTL_STR
+#undef SYSCTL_INT
+#undef SYSCTL_BOOL
+
+int
+SysCtl_Lookup(const char *path)
+{
+    int i;
+
+    for (i = 0; SYSCTLTable[i].path[0] != '\0'; i++) {
+	if (strcmp(path, SYSCTLTable[i].path) == 0)
+	    return i;
+    }
+
+    return -1;
+}
+
+void
+Debug_SysCtl(int argc, const char *argv[])
+{
+    int i;
+
+    if (argc == 1) {
+        kprintf("%-20s %s\n", "Name", "Description");
+	for (i = 0; SYSCTLTable[i].path[0] != '\0'; i++) {
+	    kprintf("%-20s %s\n", SYSCTLTable[i].path, SYSCTLTable[i].description);
+	}
+
+	return;
+    }
+
+    i = SysCtl_Lookup(argv[1]);
+    if (i == -1) {
+	kprintf("Unknown sysctl node!\n");
+	return;
+    }
+
+    if (argc == 2) {
+	switch (SYSCTLTable[i].type) {
+	    case SYSCTL_TYPE_STR: {
+		SysCtlString *val = (SysCtlString *)SYSCTLTable[i].node;
+		kprintf("%s: %s\n", argv[1], val->value);
+		break;
+	    }
+	    case SYSCTL_TYPE_INT: {
+		SysCtlInt *val = (SysCtlInt *)SYSCTLTable[i].node;
+		kprintf("%s: %ld\n", argv[1], val->value);
+		break;
+	    }
+	    case SYSCTL_TYPE_BOOL: {
+		SysCtlBool *val = (SysCtlBool *)SYSCTLTable[i].node;
+		kprintf("%s: %s\n", argv[1], val->value ? "true" : "false");
+		break;
+	    }
+	}
+
+	return;
+    }
+}
+
+REGISTER_DBGCMD(sysctl, "SYSCTL", Debug_SysCtl);
+