Generic plug-and-play enumerator infrastructure. Query supplied

enumerators, crossreference returned identifiers with a text-format
database and automatically load corresponding modules and dependancies.

1 files changed, 221 insertions, 0 deletions

diff --git a/sys/boot/common/pnp.c b/sys/boot/common/pnp.c
new file mode 100644
index 0000000..d0b6061
--- /dev/null
+++ b/sys/boot/common/pnp.c
@@ -0,0 +1,221 @@
+/*
+ * mjs copyright
+ */
+/*
+ * "Plug and Play" functionality.
+ *
+ * We use the PnP enumerators to obtain identifiers for installed hardware,
+ * and the contents of a database to determine modules to be loaded to support
+ * such hardware.
+ */
+
+#include <stand.h>
+#include <bootstrap.h>
+
+static struct pnpinfo	*pnp_devices = NULL;
+
+static void		pnp_discard(void);
+
+/*
+ * Perform complete enumeration sweep, and load required module(s) if possible.
+ */
+
+int
+pnp_autoload(void) 
+{
+    int			hdlr, idx;
+
+    /* forget anything we think we knew */
+    pnp_discard();
+
+    /* iterate over all of the handlers */
+    for (hdlr = 0; pnphandlers[hdlr]->pp_name != NULL; i++) {
+	printf("Probing bus '%s'...\n", pnphandlers[hdlr]->pp_name);
+	idx = 0;
+	while ((pi = pnphandlers[hdlr]->pp_enumerate(idx++)) != NULL) {
+	    printf("  %s\n", pi->pi_ident);
+	    pi->pi_handler = hdlr;
+	    pi->pi_next = pnp_devices;
+	    pnp_devices = pi;
+	}
+    }
+    /* find anything? */
+    if (pnp_devices != NULL) {
+	/* XXX hardcoded paths! should use loaddev? */
+	pnp_readconf("/boot/pnpdata.local");
+	pnp_readconf("/boot/pnpdata");
+
+	pnp_reload();
+    }
+}
+
+/*
+ * Try to load outstanding modules (eg. after disk change)
+ */
+int
+pnp_reload(void)
+{
+    struct pnpinfo	*pi;
+    char		*modfname;
+	
+    /* try to load any modules that have been nominated */
+    for (pi = pnp_devices; pi != NULL; pi = pi->pi_next) {
+	/* Already loaded? */
+	if ((pi->pi_module != NULL) && (mod_findmodule(pi->pi_module, NULL) == NULL)) {
+	    modfname = malloc(strlen(pi->pi_module + 3));
+	    sprintf(modfname, "%s.ko", pi->pi_module);	/* XXX implicit knowledge of KLD module filenames */
+	    if (mod_load(pi->pi_module, pi->pi_argc, pi->pi_argv))
+		printf("Could not load module '%s' for device '%s'\n", modfname, pi->pi_ident);
+	    free(modfname);
+	}
+    }
+}
+
+
+/*
+ * Throw away anything we think we know about PnP devices
+ */
+static void
+pnp_discard(void)
+{
+    struct pnpinfo	*pi;
+    
+    while (pnp_devices != NULL) {
+	pi = pnp_devices;
+	pnp_devices = pnp_devices->pi_next;
+	if (pi->pi_ident)
+	    free(pi->pi_ident);
+	if (pi->pi_module)
+	    free(pi->pi_module);
+	if (pi->pi_argv)
+	    free(pi->pi_argv);
+	free(pi);
+    }
+}
+
+/*
+ * The PnP configuration database consists of a flat text file with 
+ * entries one per line.  Valid lines are:
+ *
+ * # <text>
+ *
+ * 	This line is a comment, and ignored.
+ *
+ * [<name>]
+ *
+ *	Entries following this line are for devices connected to the
+ *	bus <name>, At least one such entry must be encountered
+ *	before identifiers are recognised.
+ *
+ * ident=<identifier> rev=<revision> module=<module> args=<arguments>
+ *
+ *	This line describes an identifier:module mapping.  The 'ident'
+ *	and 'module' fields are required; the 'rev' field is currently
+ *	ignored (but should be used), and the 'args' field must come
+ *	last.
+ */
+static void
+pnp_readconf(char *path)
+{
+    struct pnpinfo	*pi;
+    int			fd, line;
+    char		lbuf[128], *currbus, *ident, *revision, *module, *args;
+    char		*cp, *ep, *tp, c;
+
+    /* try to open the file */
+    if ((fd = open(path, O_RDONLY)) >= 0) {
+	line = 0;
+	currbus = NULL;
+	
+	while (fgetstr(lbuf, sizeof(lbuf), fd) > 0) {
+	    line++;
+	    /* Find the first non-space character on the line */
+	    for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
+		;
+	    
+	    /* keep/discard? */
+	    if ((*cp == 0) || (*cp == '#'))
+		continue;
+	    
+	    /* bus declaration? */
+	    if (*cp == '[') {
+		if (((ep = strchr(cp, ']')) == NULL) || ((ep - cp) < 2)) {
+		    printf("%s line %d: bad bus specification\n", path, line);
+		} else {
+		    if (currbus != NULL)
+			free(currbus);
+		    *ep = 0;
+		    currbus = strdup(cp + 1);
+		}
+		continue;
+	    }
+
+	    /* XXX should we complain? */
+	    if (currbus == NULL)
+		continue;
+
+	    /* mapping */
+	    for (ident = module = args = NULL; *cp != 0;) {
+
+		/* discard leading whitespace */
+		if (isspace(*cp)) {
+		    cp++;
+		    continue;
+		}
+		
+		/* scan for terminator, separator */
+		for (ep = cp; (*ep != 0) && (*ep != '=') && !isspace(ep); ep++)
+		    ;
+
+		if (*ep == '=') {
+		    *ep = 0;
+		    for (tp = ep + 1; (*tp != 0) && !isspace(tp); tp++)
+			;
+		    c = *tp;
+		    *tp = 0;
+		    if ((ident == NULL) && !strcmp(cp, "ident")) {
+			ident = ep + 1;
+		    } else if ((revision == NULL) && !strcmp(cp, "revision")) {
+			revision = ep + 1;
+		    } else if ((args == NULL) && !strcmp(cp, "args")) {
+			*tp = c;
+			while (*tp != 0)		/* skip to end of string */
+			    tp++;
+			args = ep + 1;
+		    } else {
+			/* XXX complain? */
+		    }
+		    cp = tp;
+		    continue;
+		}
+		
+		/* it's garbage or a keyword - ignore it for now */
+		cp = ep;
+	    }
+
+	    /* we must have at least ident and module set */
+	    if ((ident == NULL) || (module == NULL)) {
+		printf("%s line %d: bad mapping\n", path, line);
+		continue;
+	    }
+	    
+	    /*
+	     * Loop looking for module/bus that might match this 
+	     * XXX no revision parse/test here yet.
+	     */
+	    for (pi = pnp_modules; pi != NULL; pi = pi->pi_next) {
+		if (!strcmp(pnphandlers[pi->pi_handler]->pp_name, currbus) &&
+		    !strcmp(pi->pi_indent, ident)) {
+		    if (args != NULL)
+			if (parse(&pi->pi_argc, &pi->pi_argv, args)) {
+			    printf("%s line %d: bad arguments\n", path, line);
+			    break;
+			}
+		    pi->pi_module = strdup(module);
+		}
+	    }
+	}
+	close(fd);
+    }
+}
+