[app][lkboot] provide a means to register additional commands

app/lkboot/commands.c

@@ -27,6 +27,7 @@
 #include <debug.h>
 #include <string.h>
 #include <endian.h>
+#include <malloc.h>
 
 #include <kernel/thread.h>
 
@@ -34,22 +35,38 @@
 #include <lib/bio.h>
 #include <lib/sysparam.h>
 
+#include <app/lkboot.h>
+
 #if PLATFORM_ZYNQ
 #include <platform/fpga.h>
 #endif
 
 #define bootdevice "spi0"
 
-typedef struct LKB lkb_t;
-
-// returns 0 on success, -1 on failure (short read or io error)
-int lkb_read(lkb_t *lkb, void *data, size_t len);
-int lkb_write(lkb_t *lkb, const void *data, size_t len);
-
 extern void *lkb_iobuffer;
 extern paddr_t lkb_iobuffer_phys;
 extern size_t lkb_iobuffer_size;
 
+struct lkb_command {
+	struct lkb_command *next;
+	const char *name;
+	lkb_handler_t handler;
+	void *cookie;
+};
+
+struct lkb_command *lkb_cmd_list = NULL;
+
+void lkb_register(const char *name, lkb_handler_t handler, void *cookie) {
+	struct lkb_command *cmd = malloc(sizeof(struct lkb_command));
+	if (cmd != NULL) {
+		cmd->next = lkb_cmd_list;
+		cmd->name = name;
+		cmd->handler = handler;
+		cmd->cookie = cookie;
+		lkb_cmd_list = cmd;
+	}
+}
+
 static int do_reboot(void *arg) {
 	thread_sleep(250);
 	platform_halt(HALT_ACTION_REBOOT, HALT_REASON_SW_RESET);
@@ -58,6 +75,13 @@ static int do_reboot(void *arg) {
 
 // return NULL for success, error string for failure
 const char *lkb_handle_command(lkb_t *lkb, const char *cmd, const char *arg, unsigned len) {
+	struct lkb_command *lcmd;
+	for (lcmd = lkb_cmd_list; lcmd; lcmd = lcmd->next) {
+		if (!strcmp(lcmd->name, cmd)) {
+			return lcmd->handler(lkb, arg, len, lcmd->cookie);
+		}
+	}
+
 	if (len > lkb_iobuffer_size) {
 		return "buffer too small";
 	}

app/lkboot/include/app/lkboot.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2014 Brian Swetland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+typedef struct LKB lkb_t;
+
+// lkb_read/write may *only* be called from within a lkb_handler()
+// len of 0 is invalid for both
+
+// returns 0 on success, -1 on failure (io error, etc)
+int lkb_read(lkb_t *lkb, void *data, size_t len);
+int lkb_write(lkb_t *lkb, const void *data, size_t len);
+
+// len is the number of bytes the host has declared that it will send
+// use lkb_read() to read some or all of this data
+// return NULL on success, or an asciiz string (message) for error
+typedef const char* (*lkb_handler_t)(lkb_t *lkb,
+	const char *arg, unsigned len, void *cookie);
+
+// cmd must be a string constant
+void lkb_register(const char *cmd, lkb_handler_t handler, void *cookie);
+

app/lkboot/rules.mk

@@ -11,4 +11,6 @@ MODULE_SRCS += \
 	$(LOCAL_DIR)/lkboot.c \
 	$(LOCAL_DIR)/commands.c
 
+GLOBAL_INCLUDES += $(LOCAL_DIR)/include
+
 include make/module.mk