API for external applications.

This is an API for external (standalone) applications running on top of
U-Boot, and is meant to be more extensible and robust than the existing
jumptable mechanism. It is similar to UNIX syscall approach. See api/README
for more details.

Included is the demo application using this new framework (api_examples).

Please note this is still an experimental feature, and is turned off by
default.

Signed-off-by: Rafal Jaworowski <raj@semihalf.com>
diff --git a/api_examples/glue.c b/api_examples/glue.c
new file mode 100644
index 0000000..7598369
--- /dev/null
+++ b/api_examples/glue.c
@@ -0,0 +1,405 @@
+/*
+ * (C) Copyright 2007 Semihalf
+ *
+ * Written by: Rafal Jaworowski <raj@semihalf.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <linux/types.h>
+#include <api_public.h>
+
+#include "glue.h"
+
+static int valid_sig(struct api_signature *sig)
+{
+	uint32_t checksum;
+	struct api_signature s;
+
+	if (sig == NULL)
+		return 0;
+	/*
+	 * Clear the checksum field (in the local copy) so as to calculate the
+	 * CRC with the same initial contents as at the time when the sig was
+	 * produced
+	 */
+	s = *sig;
+	s.checksum = 0;
+
+	checksum = crc32(0, (unsigned char *)&s, sizeof(struct api_signature));
+
+	if (checksum != sig->checksum)
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Searches for the U-Boot API signature
+ *
+ * returns 1/0 depending on found/not found result
+ */
+int api_search_sig(struct api_signature **sig) {
+
+	unsigned char *sp;
+
+	if (sig == NULL)
+		return 0;
+
+	sp = (unsigned char *)API_SEARCH_START;
+
+	while ((sp + (int)API_SIG_MAGLEN) < (unsigned char *)API_SEARCH_END) {
+		if (!memcmp(sp, API_SIG_MAGIC, API_SIG_MAGLEN)) {
+			*sig = (struct api_signature *)sp;
+			if (valid_sig(*sig))
+				return 1;
+		}
+		sp += API_SIG_MAGLEN;
+	}
+
+	*sig = NULL;
+	return 0;
+}
+
+/****************************************
+ *
+ * console
+ *
+ ****************************************/
+
+int ub_getc(void)
+{
+	int c;
+
+	if (!syscall(API_GETC, NULL, (uint32_t)&c))
+		return -1;
+
+	return c;
+}
+
+int ub_tstc(void)
+{
+	int t;
+
+	if (!syscall(API_TSTC, NULL, (uint32_t)&t))
+		return -1;
+
+	return t;
+}
+
+void ub_putc(char c)
+{
+	syscall(API_PUTC, NULL, (uint32_t)&c);
+}
+
+void ub_puts(const char *s)
+{
+	syscall(API_PUTS, NULL, (uint32_t)s);
+}
+
+/****************************************
+ *
+ * system
+ *
+ ****************************************/
+
+void ub_reset(void)
+{
+	syscall(API_RESET, NULL);
+}
+
+#define MR_MAX 5
+static struct mem_region mr[MR_MAX];
+static struct sys_info si;
+
+struct sys_info * ub_get_sys_info(void)
+{
+	int err = 0;
+
+	memset(&si, 0, sizeof(struct sys_info));
+	si.mr = mr;
+	si.mr_no = MR_MAX;
+	memset(&mr, 0, sizeof(mr));
+
+	if (!syscall(API_GET_SYS_INFO, &err, (u_int32_t)&si))
+		return NULL;
+
+	return ((err) ? NULL : &si);
+}
+
+/****************************************
+ *
+ * timing
+ *
+ ****************************************/
+ 
+void ub_udelay(unsigned long usec)
+{
+	syscall(API_UDELAY, NULL, &usec);
+}
+
+unsigned long ub_get_timer(unsigned long base)
+{
+	unsigned long cur;
+
+	if (!syscall(API_GET_TIMER, NULL, &cur, &base))
+		return 0;
+
+	return cur;
+}
+
+
+/****************************************************************************
+ *
+ * devices
+ *
+ * Devices are identified by handles: numbers 0, 1, 2, ..., MAX_DEVS-1
+ *
+ ***************************************************************************/
+
+#define MAX_DEVS 6
+
+static struct device_info devices[MAX_DEVS];
+
+struct device_info * ub_dev_get(int i)
+{
+	return ((i < 0 || i >= MAX_DEVS) ? NULL : &devices[i]);
+}
+
+/*
+ * Enumerates the devices: fills out device_info elements in the devices[]
+ * array.
+ *
+ * returns:		number of devices found
+ */
+int ub_dev_enum(void)
+{
+	struct device_info *di;
+	int n = 0;
+
+	memset(&devices, 0, sizeof(struct device_info) * MAX_DEVS);
+	di = &devices[0];
+
+	if (!syscall(API_DEV_ENUM, NULL, di))
+		return 0;
+
+	while (di->cookie != NULL) {
+
+		if (++n >= MAX_DEVS)
+			break;
+
+		/* take another device_info */
+		di++;
+
+		/* pass on the previous cookie */
+		di->cookie = devices[n - 1].cookie;
+
+		if (!syscall(API_DEV_ENUM, NULL, di))
+			return 0;
+	}
+
+	return n;
+}
+
+/*
+ * handle:	0-based id of the device
+ *
+ * returns:	0 when OK, err otherwise
+ */
+int ub_dev_open(int handle)
+{
+	struct device_info *di;
+	int err = 0;
+
+	if (handle < 0 || handle >= MAX_DEVS)
+		return API_EINVAL;
+
+	di = &devices[handle];
+
+	if (!syscall(API_DEV_OPEN, &err, di))
+		return -1;
+
+	return err;
+}
+
+int ub_dev_close(int handle)
+{
+	struct device_info *di;
+
+	if (handle < 0 || handle >= MAX_DEVS)
+		return API_EINVAL;
+
+	di = &devices[handle];
+	if (!syscall(API_DEV_CLOSE, NULL, di))
+		return -1;
+
+	return 0;
+}
+
+/*
+ *
+ * Validates device for read/write, it has to:
+ *
+ * - have sane handle
+ * - be opened
+ *
+ * returns:	0/1 accordingly
+ */
+static int dev_valid(int handle)
+{
+	if (handle < 0 || handle >= MAX_DEVS)
+		return 0;
+
+	if (devices[handle].state != DEV_STA_OPEN)
+		return 0;
+
+	return 1;
+}
+
+static int dev_stor_valid(int handle)
+{
+	if (!dev_valid(handle))
+		return 0;
+
+	if (!(devices[handle].type & DEV_TYP_STOR))
+		return 0;
+
+	return 1;
+}
+
+int ub_dev_read(int handle, void *buf, lbasize_t len, lbastart_t start)
+{
+	struct device_info *di;
+	lbasize_t act_len;
+	int err = 0;
+
+	if (!dev_stor_valid(handle))
+		return API_ENODEV;
+
+	di = &devices[handle];
+	if (!syscall(API_DEV_READ, &err, di, buf, &len, &start, &act_len))
+		return -1;
+
+	if (err) 
+		return err;
+
+	if (act_len != len)
+		return API_EIO;
+
+	return 0;
+}
+
+static int dev_net_valid(int handle)
+{
+	if (!dev_valid(handle))
+		return 0;
+
+	if (devices[handle].type != DEV_TYP_NET)
+		return 0;
+
+	return 1;
+}
+
+int ub_dev_recv(int handle, void *buf, int len)
+{
+	struct device_info *di;
+	int err = 0, act_len;
+
+	if (!dev_net_valid(handle))
+		return API_ENODEV;
+
+	di = &devices[handle];
+	if (!syscall(API_DEV_READ, &err, di, buf, &len, &act_len))
+		return -1;
+
+	if (err)
+		return -1;
+
+	return act_len;
+}
+
+int ub_dev_send(int handle, void *buf, int len)
+{
+	struct device_info *di;
+	int err = 0;
+
+	if (!dev_net_valid(handle))
+		return API_ENODEV;
+
+	di = &devices[handle];
+	if (!syscall(API_DEV_WRITE, &err, di, buf, &len))
+		return -1;
+
+	return err;
+}
+
+/****************************************
+ *
+ * env vars
+ *
+ ****************************************/
+
+char * ub_env_get(const char *name)
+{
+	char *value;
+
+	if (!syscall(API_ENV_GET, NULL, (uint32_t)name, (uint32_t)&value))
+		return NULL;
+
+	return value;
+}
+
+void ub_env_set(const char *name, char *value)
+{
+	syscall(API_ENV_SET, NULL, (uint32_t)name, (uint32_t)value);
+}
+
+
+static char env_name[256];
+
+const char * ub_env_enum(const char *last)
+{
+	const char *env, *str;
+	int i;
+
+	env = NULL;
+
+	/*
+	 * It's OK to pass only the name piece as last (and not the whole
+	 * 'name=val' string), since the API_ENUM_ENV call uses envmatch()
+	 * internally, which handles such case
+	 */
+	if (!syscall(API_ENV_ENUM, NULL, (uint32_t)last, (uint32_t)&env))
+		return NULL;
+
+	if (!env)
+		/* no more env. variables to enumerate */
+		return NULL;
+
+	/* next enumerated env var */
+	memset(env_name, 0, 256);
+	for (i = 0, str = env; *str != '=' && *str != '\0';)
+		env_name[i++] = *str++;
+
+	env_name[i] = '\0';
+
+	return env_name;
+}