Initial loader(8) support for Flattened Device Tree.

o This is disabled by default for now, and can be enabled using WITH_FDT at
  build time.

o Tested with ARM and PowerPC.

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation

1 files changed, 1290 insertions, 0 deletions

diff --git a/sys/boot/fdt/fdt_loader_cmd.c b/sys/boot/fdt/fdt_loader_cmd.c
new file mode 100644
index 0000000..46c6d9a
--- /dev/null
+++ b/sys/boot/fdt/fdt_loader_cmd.c
@@ -0,0 +1,1290 @@
+/*-
+ * Copyright (c) 2009-2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Semihalf under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stand.h>
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "bootstrap.h"
+#include "glue.h"
+
+#define DEBUG
+
+#ifdef DEBUG
+#define debugf(fmt, args...) do { printf("%s(): ", __func__);	\
+    printf(fmt,##args); } while (0)
+#else
+#define debugf(fmt, args...)
+#endif
+
+#define FDT_CWD_LEN	256
+#define FDT_MAX_DEPTH	6
+
+#define FDT_PROP_SEP	" = "
+
+#define STR(number) #number
+#define STRINGIFY(number) STR(number)
+
+#define MIN(num1, num2)	(((num1) < (num2)) ? (num1):(num2))
+
+static struct fdt_header *fdtp = NULL;
+
+static int fdt_cmd_nyi(int argc, char *argv[]);
+
+static int fdt_cmd_mkprop(int argc, char *argv[]);
+static int fdt_cmd_cd(int argc, char *argv[]);
+static int fdt_cmd_hdr(int argc, char *argv[]);
+static int fdt_cmd_ls(int argc, char *argv[]);
+static int fdt_cmd_prop(int argc, char *argv[]);
+static int fdt_cmd_pwd(int argc, char *argv[]);
+static int fdt_cmd_rm(int argc, char *argv[]);
+static int fdt_cmd_mknode(int argc, char *argv[]);
+
+typedef int cmdf_t(int, char *[]);
+
+struct cmdtab {
+	char	*name;
+	cmdf_t	*handler;
+};
+
+static const struct cmdtab commands[] = {
+	{ "alias", &fdt_cmd_nyi },
+	{ "cd", &fdt_cmd_cd },
+	{ "header", &fdt_cmd_hdr },
+	{ "ls", &fdt_cmd_ls },
+	{ "mknode", &fdt_cmd_mknode },
+	{ "mkprop", &fdt_cmd_mkprop },
+	{ "mres", &fdt_cmd_nyi },
+	{ "prop", &fdt_cmd_prop },
+	{ "pwd", &fdt_cmd_pwd },
+	{ "rm", &fdt_cmd_rm },
+	{ NULL, NULL }
+};
+
+static char cwd[FDT_CWD_LEN] = "/";
+
+static int
+fdt_setup_fdtp()
+{
+	struct preloaded_file *bfp;
+	int err;
+
+	/*
+	 * Find the device tree blob.
+	 */
+	bfp = file_findfile(NULL, "dtb");
+	if (bfp == NULL) {
+		command_errmsg = "no device tree blob loaded";
+		return (CMD_ERROR);
+	}
+	fdtp = (struct fdt_header *)bfp->f_addr;
+
+	/*
+	 * Validate the blob.
+	 */
+	err = fdt_check_header(fdtp);
+	if (err < 0) {
+		if (err == -FDT_ERR_BADVERSION)
+			sprintf(command_errbuf,
+			    "incompatible blob version: %d, should be: %d",
+			    fdt_version(fdtp), FDT_LAST_SUPPORTED_VERSION);
+
+		else
+			sprintf(command_errbuf, "error validating blob: %s",
+			    fdt_strerror(err));
+		return (CMD_ERROR);
+	}
+	return (CMD_OK);
+}
+
+#define fdt_strtovect(str, cellbuf, lim, cellsize) _fdt_strtovect((str), \
+    (cellbuf), (lim), (cellsize), 0);
+
+/* Force using base 16 */
+#define fdt_strtovectx(str, cellbuf, lim, cellsize) _fdt_strtovect((str), \
+    (cellbuf), (lim), (cellsize), 16);
+
+static int
+_fdt_strtovect(char *str, void *cellbuf, int lim, unsigned char cellsize,
+    uint8_t base)
+{
+	char *buf = str;
+	char *end = str + strlen(str) - 2;
+	uint32_t *u32buf = NULL;
+	uint8_t *u8buf = NULL;
+	int cnt = 0;
+
+	if (cellsize == sizeof(uint32_t))
+		u32buf = (uint32_t *)cellbuf;
+	else
+		u8buf = (uint8_t *)cellbuf;
+
+	if (lim == 0)
+		return (0);
+
+	while (buf < end) {
+
+		/* Skip white whitespace(s)/separators */
+		while (!isxdigit(*buf) && buf < end)
+			buf++;
+
+		if (u32buf != NULL)
+			u32buf[cnt] =
+			    cpu_to_fdt32((uint32_t)strtol(buf, NULL, base));
+
+		else
+			u8buf[cnt] = (uint8_t)strtol(buf, NULL, base);
+
+		if (cnt + 1 <= lim - 1)
+			cnt++;
+		else
+			break;
+		buf++;
+		/* Find another number */
+		while ((isxdigit(*buf) || *buf == 'x') && buf < end)
+			buf++;
+	}
+	return (cnt);
+}
+
+#define	TMP_MAX_ETH	8
+
+void
+fixup_ethernet(const char *env, char *ethstr, int *eth_no, int len)
+{
+	char *end, *str;
+	uint8_t tmp_addr[6];
+	int i, n;
+
+	/* Extract interface number */
+	i = strtol(env + 3, &end, 10);
+	if (end == (env + 3))
+		/* 'ethaddr' means interface 0 address */
+		n = 0;
+	else
+		n = i;
+
+	if (n > TMP_MAX_ETH)
+		return;
+
+	str = ub_env_get(env);
+
+	/* Convert macaddr string into a vector of uints */
+	fdt_strtovectx(str, &tmp_addr, 6, sizeof(uint8_t));
+	if (n != 0) {
+		i = strlen(env) - 7;
+		strncpy(ethstr + 8, env + 3, i);
+	}
+	/* Set actual property to a value from vect */
+	fdt_setprop(fdtp, fdt_path_offset(fdtp, ethstr),
+	    "local-mac-address", &tmp_addr, 6 * sizeof(uint8_t));
+
+	/* Clear ethernet..XXXX.. string */
+	bzero(ethstr + 8, len - 8);
+
+	if (n + 1 > *eth_no)
+		*eth_no = n + 1;
+}
+
+void
+fixup_cpubusfreqs(unsigned long cpufreq, unsigned long busfreq)
+{
+	int lo, o = 0, o2, maxo = 0, depth;
+	const uint32_t zero = 0;
+
+	/* We want to modify every subnode of /cpus */
+	o = fdt_path_offset(fdtp, "/cpus");
+
+	/* maxo should contain offset of node next to /cpus */
+	depth = 0;
+	maxo = o;
+	while (depth != -1)
+		maxo = fdt_next_node(fdtp, maxo, &depth);
+
+	/* Find CPU frequency properties */
+	o = fdt_node_offset_by_prop_value(fdtp, o, "clock-frequency",
+	    &zero, sizeof(uint32_t));
+
+	o2 = fdt_node_offset_by_prop_value(fdtp, o, "bus-frequency", &zero,
+	    sizeof(uint32_t));
+
+	lo = MIN(o, o2);
+
+	while (o != -FDT_ERR_NOTFOUND && o2 != -FDT_ERR_NOTFOUND) {
+
+		o = fdt_node_offset_by_prop_value(fdtp, lo,
+		    "clock-frequency", &zero, sizeof(uint32_t));
+
+		o2 = fdt_node_offset_by_prop_value(fdtp, lo, "bus-frequency",
+		    &zero, sizeof(uint32_t));
+
+		/* We're only interested in /cpus subnode(s) */
+		if (lo > maxo)
+			break;
+
+		fdt_setprop_inplace_cell(fdtp, lo, "clock-frequency",
+		    (uint32_t)cpufreq);
+
+		fdt_setprop_inplace_cell(fdtp, lo, "bus-frequency",
+		    (uint32_t)busfreq);
+
+		lo = MIN(o, o2);
+	}
+}
+
+int
+fdt_reg_valid(uint32_t *reg, int len, int addr_cells, int size_cells)
+{
+	int cells_in_tuple, i, tuples, tuple_size;
+	uint32_t cur_start, cur_size;
+
+	cells_in_tuple = (addr_cells + size_cells);
+	tuple_size = cells_in_tuple * sizeof(uint32_t);
+	tuples = len / tuple_size;
+	if (tuples == 0)
+		return (EINVAL);
+
+	for (i = 0; i < tuples; i++) {
+		if (addr_cells == 2)
+			cur_start = fdt64_to_cpu(reg[i * cells_in_tuple]);
+		else
+			cur_start = fdt32_to_cpu(reg[i * cells_in_tuple]);
+
+		if (size_cells == 2)
+			cur_size = fdt64_to_cpu(reg[i * cells_in_tuple + 2]);
+		else
+			cur_size = fdt32_to_cpu(reg[i * cells_in_tuple + 1]);
+
+		if (cur_size == 0)
+			return (EINVAL);
+
+		debugf(" reg#%d (start: 0x%0x size: 0x%0x) valid!\n",
+		    i, cur_start, cur_size);
+	}
+	return (0);
+}
+
+void
+fixup_memory(struct sys_info *si)
+{
+	struct mem_region *curmr;
+	uint32_t addr_cells, size_cells;
+	uint32_t *addr_cellsp, *reg,  *size_cellsp;
+	int err, i, len, memory, realmrno, root;
+	uint8_t *buf, *sb;
+
+	root = fdt_path_offset(fdtp, "/");
+	if (root < 0) {
+		sprintf(command_errbuf, "Could not find root node !");
+		return;
+	}
+
+	memory = fdt_path_offset(fdtp, "/memory");
+	if (memory <= 0) {
+		/* Create proper '/memory' node. */
+		memory = fdt_add_subnode(fdtp, root, "memory");
+		if (memory <= 0) {
+			sprintf(command_errbuf, "Could not fixup '/memory' "
+			    "node, error code : %d!\n", memory);
+			return;
+		}
+
+		err = fdt_setprop(fdtp, memory, "device_type", "memory",
+		    sizeof("memory"));
+
+		if (err < 0)
+			return;
+	}
+
+	addr_cellsp = (uint32_t *)fdt_getprop(fdtp, root, "#address-cells",
+	    NULL);
+	size_cellsp = (uint32_t *)fdt_getprop(fdtp, root, "#size-cells", NULL);
+
+	if (addr_cellsp == NULL || size_cellsp == NULL) {
+		sprintf(command_errbuf, "Could not fixup '/memory' node : "
+		    "%s %s property not found in root node!\n",
+		    (!addr_cellsp) ? "#address-cells" : "",
+		    (!size_cellsp) ? "#size-cells" : "");
+		return;
+	}
+
+	addr_cells = fdt32_to_cpu(*addr_cellsp);
+	size_cells = fdt32_to_cpu(*size_cellsp);
+
+	/* Count valid memory regions entries in sysinfo. */
+	realmrno = si->mr_no;
+	for (i = 0; i < si->mr_no; i++)
+		if (si->mr[i].start == 0 && si->mr[i].size == 0)
+			realmrno--;
+
+	if (realmrno == 0) {
+		sprintf(command_errbuf, "Could not fixup '/memory' node : "
+		    "sysinfo doesn't contain valid memory regions info!\n");
+		return;
+	}
+
+	if ((reg = (uint32_t *)fdt_getprop(fdtp, memory, "reg",
+	    &len)) != NULL) {
+
+		if (fdt_reg_valid(reg, len, addr_cells, size_cells) == 0)
+			/*
+			 * Do not apply fixup if existing 'reg' property
+			 * seems to be valid.
+			 */
+			return;
+	}
+
+	len = (addr_cells + size_cells) * realmrno * sizeof(uint32_t);
+	sb = buf = (uint8_t *)malloc(len);
+	if (!buf)
+		return;
+
+	bzero(buf, len);
+
+	for (i = 0; i < si->mr_no; i++) {
+		curmr = &si->mr[i];
+		if (curmr->size != 0) {
+			/* Ensure endianess, and put cells into a buffer */
+			if (addr_cells == 2)
+				*(uint64_t *)buf =
+				    cpu_to_fdt64(curmr->start);
+			else
+				*(uint32_t *)buf =
+				    cpu_to_fdt32(curmr->start);
+
+			buf += sizeof(uint32_t) * addr_cells;
+			if (size_cells == 2)
+				*(uint64_t *)buf =
+				    cpu_to_fdt64(curmr->size);
+			else
+				*(uint32_t *)buf =
+				    cpu_to_fdt32(curmr->size);
+
+			buf += sizeof(uint32_t) * size_cells;
+		}
+	}
+
+	/* Set property */
+	if ((err = fdt_setprop(fdtp, memory, "reg", sb, len)) < 0)
+		sprintf(command_errbuf, "Could not fixup '/memory' node.\n");
+}
+
+void
+fixup_stdout(const char *env)
+{
+	const char *str;
+	char *ptr;
+	int serialno;
+	int len, no, sero;
+	const struct fdt_property *prop;
+	char *tmp[10];
+
+	str = ub_env_get(env);
+	ptr = (char *)str + strlen(str) - 1;
+	while (ptr > str && isdigit(*(str - 1)))
+		str--;
+
+	if (ptr == str)
+		return;
+
+	serialno = (int)strtol(ptr, NULL, 0);
+	no = fdt_path_offset(fdtp, "/chosen");
+	if (no < 0)
+		return;
+
+	prop = fdt_get_property(fdtp, no, "stdout", &len);
+
+	/* If /chosen/stdout does not extist, create it */
+	if (prop == NULL || (prop != NULL && len == 0)) {
+
+		bzero(tmp, 10 * sizeof(char));
+		strcpy((char *)&tmp, "serial");
+		if (strlen(ptr) > 3)
+			/* Serial number too long */
+			return;
+
+		strncpy((char *)tmp + 6, ptr, 3);
+		sero = fdt_path_offset(fdtp, (const char *)tmp);
+		if (sero < 0)
+			/*
+			 * If serial device we're trying to assign
+			 * stdout to doesn't exist in DT -- return.
+			 */
+			return;
+
+		fdt_setprop(fdtp, no, "stdout", &tmp,
+		    strlen((char *)&tmp) + 1);
+		fdt_setprop(fdtp, no, "stdin", &tmp,
+		    strlen((char *)&tmp) + 1);
+	}
+}
+
+int
+fdt_fixup(void)
+{
+	const char *env;
+	char *ethstr;
+	int chosen, err, eth_no, len;
+	struct sys_info *si;
+
+	env = NULL;
+	eth_no = 0;
+	ethstr = NULL;
+	len = 0;
+
+	if (!fdtp) {
+		err = fdt_setup_fdtp();
+		if (err) {
+			sprintf(command_errbuf, "Could not perform blob "
+			    "fixups. Error code: %d\n", err);
+			return (err);
+		}
+	}
+
+	/* Create /chosen node (if not exists) */
+	if ((chosen = fdt_subnode_offset(fdtp, 0, "chosen")) ==
+	    -FDT_ERR_NOTFOUND)
+		chosen = fdt_add_subnode(fdtp, 0, "chosen");
+
+	/* Value assigned to fixup-applied does not matter. */
+	if (fdt_getprop(fdtp, chosen, "fixup-applied", NULL))
+		return (CMD_OK);
+
+	/* Acquire sys_info */
+	si = ub_get_sys_info();
+
+	while ((env = ub_env_enum(env)) != NULL) {
+		if (strncmp(env, "eth", 3) == 0 &&
+		    strncmp(env + (strlen(env) - 4), "addr", 4) == 0) {
+			/*
+			 * Handle Ethernet addrs: parse uboot env eth%daddr
+			 */
+
+			if (!eth_no) {
+				/*
+				 * Check how many chars we will need to store
+				 * maximal eth iface number.
+				 */
+				len = strlen(STRINGIFY(TMP_MAX_ETH)) +
+				    strlen("ethernet");
+
+				/*
+				 * Reserve mem for string "ethernet" and len
+				 * chars for iface no.
+				 */
+				ethstr = (char *)malloc(len * sizeof(char));
+				bzero(ethstr, len * sizeof(char));
+				strcpy(ethstr, "ethernet0");
+			}
+
+			/* Modify blob */
+			fixup_ethernet(env, ethstr, &eth_no, len);
+
+		} else if (strcmp(env, "consoledev") == 0)
+			fixup_stdout(env);
+	}
+
+	/* Modify cpu(s) and bus clock frequenties in /cpus node [Hz] */
+	fixup_cpubusfreqs(si->clk_cpu, si->clk_bus);
+
+	/* Fixup memory regions */
+	fixup_memory(si);
+
+	fdt_setprop(fdtp, chosen, "fixup-applied", NULL, 0);
+
+	return (CMD_OK);
+}
+
+int
+command_fdt_internal(int argc, char *argv[])
+{
+	cmdf_t *cmdh;
+	char *cmd;
+	int i, err;
+
+	if (argc < 2) {
+		command_errmsg = "usage is 'fdt <command> [<args>]";
+		return (CMD_ERROR);
+	}
+
+	/*
+	 * Check if uboot env vars were parsed already. If not, do it now.
+	 */
+	fdt_fixup();
+
+	/*
+	 * Validate fdt <command>.
+	 */
+	cmd = strdup(argv[1]);
+	i = 0;
+	cmdh = NULL;
+	while (!(commands[i].name == NULL)) {
+		if (strcmp(cmd, commands[i].name) == 0) {
+			/* found it */
+			cmdh = commands[i].handler;
+			break;
+		}
+		i++;
+	}
+	if (cmdh == NULL) {
+		command_errmsg = "unknown command";
+		return (CMD_ERROR);
+	}
+
+	if (!fdtp)
+		if (fdt_setup_fdtp())
+			return (CMD_ERROR);
+
+	/*
+	 * Call command handler.
+	 */
+	err = (*cmdh)(argc, argv);
+
+	return (err);
+}
+
+static int
+fdt_cmd_cd(int argc, char *argv[])
+{
+	char *path;
+	char tmp[FDT_CWD_LEN];
+	int len, o;
+
+	path = (argc > 2) ? argv[2] : "/";
+
+	if (path[0] == '/') {
+		len = strlen(path);
+		if (len >= FDT_CWD_LEN)
+			goto fail;
+	} else {
+		/* Handle path specification relative to cwd */
+		len = strlen(cwd) + strlen(path) + 1;
+		if (len >= FDT_CWD_LEN)
+			goto fail;
+
+		strcpy(tmp, cwd);
+		strcat(tmp, "/");
+		strcat(tmp, path);
+		path = tmp;
+	}
+
+	o = fdt_path_offset(fdtp, path);
+	if (o < 0) {
+		sprintf(command_errbuf, "could not find node: '%s'", path);
+		return (CMD_ERROR);
+	}
+
+	strcpy(cwd, path);
+	return (CMD_OK);
+
+fail:
+	sprintf(command_errbuf, "path too long: %d, max allowed: %d",
+	    len, FDT_CWD_LEN - 1);
+	return (CMD_ERROR);
+}
+
+static int
+fdt_cmd_hdr(int argc __unused, char *argv[] __unused)
+{
+	char line[80];
+	int ver;
+
+	if (fdtp == NULL) {
+		command_errmsg = "no device tree blob pointer?!";
+		return (CMD_ERROR);
+	}
+
+	ver = fdt_version(fdtp);
+	pager_open();
+	sprintf(line, "\nFlattened device tree header (%p):\n", fdtp);
+	pager_output(line);
+	sprintf(line, " magic                   = 0x%08x\n", fdt_magic(fdtp));
+	pager_output(line);
+	sprintf(line, " size                    = %d\n", fdt_totalsize(fdtp));
+	pager_output(line);
+	sprintf(line, " off_dt_struct           = 0x%08x\n",
+	    fdt_off_dt_struct(fdtp));
+	pager_output(line);
+	sprintf(line, " off_dt_strings          = 0x%08x\n",
+	    fdt_off_dt_strings(fdtp));
+	pager_output(line);
+	sprintf(line, " off_mem_rsvmap          = 0x%08x\n",
+	    fdt_off_mem_rsvmap(fdtp));
+	pager_output(line);
+	sprintf(line, " version                 = %d\n", ver); 
+	pager_output(line);
+	sprintf(line, " last compatible version = %d\n",
+	    fdt_last_comp_version(fdtp));
+	pager_output(line);
+	if (ver >= 2) {
+		sprintf(line, " boot_cpuid              = %d\n",
+		    fdt_boot_cpuid_phys(fdtp));
+		pager_output(line);
+	}
+	if (ver >= 3) {
+		sprintf(line, " size_dt_strings         = %d\n",
+		    fdt_size_dt_strings(fdtp));
+		pager_output(line);
+	}
+	if (ver >= 17) {
+		sprintf(line, " size_dt_struct          = %d\n",
+		    fdt_size_dt_struct(fdtp));
+		pager_output(line);
+	}
+	pager_close();
+
+	return (CMD_OK);
+}
+
+static int
+fdt_cmd_ls(int argc, char *argv[])
+{
+	const char *prevname[FDT_MAX_DEPTH] = { NULL };
+	const char *name;
+	char *path;
+	int i, o, depth, len;
+
+	path = (argc > 2) ? argv[2] : NULL;
+	if (path == NULL)
+		path = cwd;
+
+	o = fdt_path_offset(fdtp, path);
+	if (o < 0) {
+		sprintf(command_errbuf, "could not find node: '%s'", path);
+		return (CMD_ERROR);
+	}
+
+	for (depth = 0;
+	    (o >= 0) && (depth >= 0);
+	    o = fdt_next_node(fdtp, o, &depth)) {
+
+		name = fdt_get_name(fdtp, o, &len);
+
+		if (depth > FDT_MAX_DEPTH) {
+			printf("max depth exceeded: %d\n", depth);
+			continue;
+		}
+
+		prevname[depth] = name;
+
+		/* Skip root (i = 1) when printing devices */
+		for (i = 1; i <= depth; i++) {
+			if (prevname[i] == NULL)
+				break;
+
+			if (strcmp(cwd, "/") == 0)
+				printf("/");
+			printf("%s", prevname[i]);
+		}
+		printf("\n");
+	}
+
+	return (CMD_OK);
+}
+
+static __inline int
+isprint(int c)
+{
+
+	return (c >= ' ' && c <= 0x7e);
+}
+
+static int
+fdt_isprint(const void *data, int len, int *count)
+{
+	const char *d;
+	char ch;
+	int yesno, i;
+
+	if (len == 0)
+		return (0);
+
+	d = (const char *)data;
+	if (d[len - 1] != '\0')
+		return (0);
+
+	*count = 0;
+	yesno = 1;
+	for (i = 0; i < len; i++) {
+		ch = *(d + i);
+		if (isprint(ch) || (ch == '\0' && i > 0)) {
+			/* Count strings */
+			if (ch == '\0')
+				(*count)++;
+			continue;
+		}
+
+		yesno = 0;
+		break;
+	}
+
+	return (yesno);
+}
+
+static int
+fdt_data_str(const void *data, int len, int count, char **buf)
+{
+	char tmp[80], *b;
+	const char *d;
+	int i, l;
+
+	/*
+	 * Calculate the length for the string and allocate memory.
+	 *
+	 * Note len already includes at least one terminator.
+	 */
+	l = len;
+	if (count > 1) {
+		/*
+		 * Each token had already a terminator buried in 'len', but we
+		 * only need one eventually, don't count space for these.
+		 */
+		l -= count - 1;
+
+		/* Each consecutive token requires a ", " separator. */
+		l += count * 2;
+	}
+	/* Space for surrounding double quotes. */
+	l += count * 2;
+
+	b = (char *)malloc(l);
+	if (b == NULL)
+		return (1);
+	b[0] = '\0';
+
+	/*
+	 * Now that we have space, format the string.
+	 */
+	i = 0;
+	do {
+		d = (const char *)data + i;
+		l = strlen(d) + 1;
+
+		sprintf(tmp, "\"%s\"%s", d,
+		    (i + l) < len ?  ", " : "");
+		strcat(b, tmp);
+
+		i += l;
+
+	} while (i < len);
+	*buf = b;
+
+	return (0);
+}
+
+static int
+fdt_data_cell(const void *data, int len, char **buf)
+{
+	char tmp[80], *b;
+	const uint32_t *c;
+	int count, i, l;
+
+	/* Number of cells */
+	count = len / 4;
+
+	/*
+	 * Calculate the length for the string and allocate memory.
+	 */
+
+	/* Each byte translates to 2 output characters */
+	l = len * 2;
+	if (count > 1) {
+		/* Each consecutive cell requires a " " separator. */
+		l += (count - 1) * 1;
+	}
+	/* Each cell will have a "0x" prefix */
+	l += count * 2;
+	/* Space for surrounding <> and terminator */
+	l += 3;
+
+	b = (char *)malloc(l);
+	if (b == NULL)
+		return (1);
+
+	b[0] = '\0';
+	strcat(b, "<");
+
+	for (i = 0; i < len; i += 4) {
+		c = (const uint32_t *)((const uint8_t *)data + i);
+		sprintf(tmp, "0x%08x%s", fdt32_to_cpu(*c),
+		    i < (len - 4) ? " " : "");
+		strcat(b, tmp);
+	}
+	strcat(b, ">");
+	*buf = b;
+
+	return (0);
+}
+
+static int
+fdt_data_bytes(const void *data, int len, char **buf)
+{
+	char tmp[80], *b;
+	const char *d;
+	int i, l;
+
+	/*
+	 * Calculate the length for the string and allocate memory.
+	 */
+
+	/* Each byte translates to 2 output characters */
+	l = len * 2;
+	if (len > 1)
+		/* Each consecutive byte requires a " " separator. */
+		l += (len - 1) * 1;
+	/* Each byte will have a "0x" prefix */
+	l += len * 2;
+	/* Space for surrounding [] and terminator. */
+	l += 3;
+
+	b = (char *)malloc(l);
+	if (b == NULL)
+		return (1);
+
+	b[0] = '\0';
+	strcat(b, "[");
+
+	for (i = 0, d = data; i < len; i++) {
+		sprintf(tmp, "0x%02x%s", d[i], i < len - 1 ? " " : "");
+		strcat(b, tmp);
+	}
+	strcat(b, "]");
+	*buf = b;
+
+	return (0);
+}
+
+static int
+fdt_data_fmt(const void *data, int len, char **buf)
+{
+	int count;
+
+	if (len == 0) {
+		*buf = NULL;
+		return (1);
+	}
+
+	if (fdt_isprint(data, len, &count))
+		return (fdt_data_str(data, len, count, buf));
+
+	else if ((len % 4) == 0)
+		return (fdt_data_cell(data, len, buf));
+
+	else
+		return (fdt_data_bytes(data, len, buf));
+}
+
+static int
+fdt_prop(int offset)
+{
+	char *line, *buf;
+	const struct fdt_property *prop;
+	const char *name;
+	const void *data;
+	int len, rv;
+
+	line = NULL;
+	prop = fdt_offset_ptr(fdtp, offset, sizeof(*prop));
+	if (prop == NULL)
+		return (1);
+
+	name = fdt_string(fdtp, fdt32_to_cpu(prop->nameoff));
+	len = fdt32_to_cpu(prop->len);
+
+	rv = 0;
+	buf = NULL;
+	if (len == 0) {
+		/* Property without value */
+		line = (char *)malloc(strlen(name) + 2);
+		if (line == NULL) {
+			rv = 2;
+			goto out2;
+		}
+		sprintf(line, "%s\n", name);
+		goto out1;
+	}
+
+	/*
+	 * Process property with value
+	 */
+	data = prop->data;
+
+	if (fdt_data_fmt(data, len, &buf) != 0) {
+		rv = 3;
+		goto out2;
+	}
+
+	line = (char *)malloc(strlen(name) + strlen(FDT_PROP_SEP) +
+	    strlen(buf) + 2);
+	if (line == NULL) {
+		sprintf(command_errbuf, "could not allocate space for string");
+		rv = 4;
+		goto out2;
+	}
+
+	sprintf(line, "%s" FDT_PROP_SEP "%s\n", name, buf);
+
+out1:
+	pager_open();
+	pager_output(line);
+	pager_close();
+
+out2:
+	if (buf)
+		free(buf);
+
+	if (line)
+		free(line);
+
+	return (rv);
+}
+
+static int
+fdt_modprop(int nodeoff, char *propname, void *value, char mode)
+{
+	uint32_t cells[100];
+	char *buf;
+	int len, rv;
+	const struct fdt_property *p;
+
+	p = fdt_get_property(fdtp, nodeoff, propname, NULL);
+
+	if (p != NULL) {
+		if (mode == 1) {
+			 /* Adding inexistant value in mode 1 is forbidden */
+			sprintf(command_errbuf, "property already exists!");
+			return (CMD_ERROR);
+		}
+	} else if (mode == 0) {
+		sprintf(command_errbuf, "property does not exist!");
+		return (CMD_ERROR);
+	}
+	len = strlen(value);
+	rv = 0;
+	buf = (char *)value;
+
+	switch (*buf) {
+	case '&':
+		/* phandles */
+		break;
+	case '<':
+		/* Data cells */
+		len = fdt_strtovect(buf, (void *)&cells, 100,
+		    sizeof(uint32_t));
+
+		rv = fdt_setprop(fdtp, nodeoff, propname, &cells,
+		    len * sizeof(uint32_t));
+		break;
+	case '[':
+		/* Data bytes */
+		len = fdt_strtovect(buf, (void *)&cells, 100,
+		    sizeof(uint8_t));
+
+		rv = fdt_setprop(fdtp, nodeoff, propname, &cells,
+		    len * sizeof(uint8_t));
+		break;
+	case '"':
+	default:
+		/* Default -- string */
+		rv = fdt_setprop_string(fdtp, nodeoff, propname, value);
+		break;
+	}
+
+	return (rv);
+}
+
+/* Merge strings from argv into a single string */
+static int
+fdt_merge_strings(int argc, char *argv[], int start, char **buffer)
+{
+	char *buf;
+	int i, idx, sz;
+
+	*buffer = NULL;
+	sz = 0;
+
+	for (i = start; i < argc; i++)
+		sz += strlen(argv[i]);
+
+	/* Additional bytes for whitespaces between args */
+	sz += argc - start;
+
+	buf = (char *)malloc(sizeof(char) * sz);
+	bzero(buf, sizeof(char) * sz);
+
+	if (buf == NULL) {
+		sprintf(command_errbuf, "could not allocate space "
+		    "for string");
+		return (1);
+	}
+
+	idx = 0;
+	for (i = start, idx = 0; i < argc; i++) {
+		strcpy(buf + idx, argv[i]);
+		idx += strlen(argv[i]);
+		buf[idx] = ' ';
+		idx++;
+	}
+	buf[sz - 1] = '\0';
+	*buffer = buf;
+	return (0);
+}
+
+/* Extract offset and name of node/property from a given path */
+static int
+fdt_extract_nameloc(char **pathp, char **namep, int *nodeoff)
+{
+	int o;
+	char *path = *pathp, *name = NULL, *subpath = NULL;
+
+	subpath = strrchr(path, '/');
+	if (subpath == NULL) {
+		o = fdt_path_offset(fdtp, cwd);
+		name = path;
+		path = (char *)&cwd;
+	} else {
+		*subpath = '\0';
+		if (strlen(path) == 0)
+			path = cwd;
+
+		name = subpath + 1;
+		o = fdt_path_offset(fdtp, path);
+	}
+
+	if (strlen(name) == 0) {
+		sprintf(command_errbuf, "name not specified");
+		return (1);
+	}
+	if (o < 0) {
+		sprintf(command_errbuf, "could not find node: '%s'", path);
+		return (1);
+	}
+	*namep = name;
+	*nodeoff = o;
+	*pathp = path;
+	return (0);
+}
+
+static int
+fdt_cmd_prop(int argc, char *argv[])
+{
+	char *path, *propname, *value;
+	int o, next, depth, rv;
+	uint32_t tag;
+
+	path = (argc > 2) ? argv[2] : NULL;
+
+	value = NULL;
+
+	if (argc > 3) {
+		/* Merge property value strings into one */
+		if (fdt_merge_strings(argc, argv, 3, &value) != 0)
+			return (CMD_ERROR);
+	} else
+		value = NULL;
+
+	if (path == NULL)
+		path = cwd;
+
+	rv = CMD_OK;
+
+	if (value) {
+		/* If value is specified -- try to modify prop. */
+		if (fdt_extract_nameloc(&path, &propname, &o) != 0)
+			return (CMD_ERROR);
+
+		rv = fdt_modprop(o, propname, value, 0);
+		if (rv)
+			return (CMD_ERROR);
+		return (CMD_OK);
+
+	}
+	/* User wants to display properties */
+	o = fdt_path_offset(fdtp, path);
+
+	if (o < 0) {
+		sprintf(command_errbuf, "could not find node: '%s'", path);
+		rv = CMD_ERROR;
+		goto out;
+	}
+
+	depth = 0;
+	while (depth >= 0) {
+		tag = fdt_next_tag(fdtp, o, &next);
+		switch (tag) {
+		case FDT_NOP:
+			break;
+		case FDT_PROP:
+			if (depth > 1)
+				/* Don't process properties of nested nodes */
+				break;
+
+			if (fdt_prop(o) != 0) {
+				sprintf(command_errbuf, "could not process "
+				    "property");
+				rv = CMD_ERROR;
+				goto out;
+			}
+			break;
+		case FDT_BEGIN_NODE:
+			depth++;
+			if (depth > FDT_MAX_DEPTH) {
+				printf("warning: nesting too deep: %d\n",
+				    depth);
+				goto out;
+			}
+			break;
+		case FDT_END_NODE:
+			depth--;
+			if (depth == 0)
+				/*
+				 * This is the end of our starting node, force
+				 * the loop finish.
+				 */
+				depth--;
+			break;
+		}
+		o = next;
+	}
+out:
+	return (rv);
+}
+
+static int
+fdt_cmd_mkprop(int argc, char *argv[])
+{
+	int o;
+	char *path, *propname, *value;
+
+	path = (argc > 2) ? argv[2] : NULL;
+
+	value = NULL;
+
+	if (argc > 3) {
+		/* Merge property value strings into one */
+		if (fdt_merge_strings(argc, argv, 3, &value) != 0)
+			return (CMD_ERROR);
+	} else
+		value = NULL;
+
+	if (fdt_extract_nameloc(&path, &propname, &o) != 0)
+		return (CMD_ERROR);
+
+	if (fdt_modprop(o, propname, value, 1))
+		return (CMD_ERROR);
+
+	return (CMD_OK);
+}
+
+static int
+fdt_cmd_rm(int argc, char *argv[])
+{
+	int o, rv;
+	char *path = NULL, *propname;
+
+	if (argc > 2)
+		path = argv[2];
+	else {
+		sprintf(command_errbuf, "no node/property name specified");
+		return (CMD_ERROR);
+	}
+
+	o = fdt_path_offset(fdtp, path);
+	if (o < 0) {
+		/* If node not found -- try to find & delete property */
+		if (fdt_extract_nameloc(&path, &propname, &o) != 0)
+			return (CMD_ERROR);
+
+		if ((rv = fdt_delprop(fdtp, o, propname)) != 0) {
+			sprintf(command_errbuf, "could not delete"
+			    "%s\n", (rv == -FDT_ERR_NOTFOUND) ?
+			    "(property/node does not exist)" : "");
+			return (CMD_ERROR);
+
+		} else
+			return (CMD_OK);
+	}
+	/* If node exists -- remove node */
+	rv = fdt_del_node(fdtp, o);
+	if (rv) {
+		sprintf(command_errbuf, "could not delete node");
+		return (CMD_ERROR);
+	}
+	return (CMD_OK);
+}
+
+static int
+fdt_cmd_mknode(int argc, char *argv[])
+{
+	int o, rv;
+	char *path = NULL, *nodename = NULL;
+
+	if (argc > 2)
+		path = argv[2];
+	else {
+		sprintf(command_errbuf, "no node name specified");
+		return (CMD_ERROR);
+	}
+
+	if (fdt_extract_nameloc(&path, &nodename, &o) != 0)
+		return (CMD_ERROR);
+
+	rv = fdt_add_subnode(fdtp, o, nodename);
+
+	if (rv < 0) {
+		sprintf(command_errbuf, "could not delete node %s\n",
+		    (rv == -FDT_ERR_NOTFOUND) ?
+		    "(node does not exist)" : "");
+		return (CMD_ERROR);
+	}
+	return (CMD_OK);
+}
+
+static int
+fdt_cmd_pwd(int argc, char *argv[])
+{
+	char line[80];
+
+	pager_open();
+	sprintf(line, "%s\n", cwd);
+	pager_output(line);
+	pager_close();
+	return (CMD_OK);
+}
+
+static int
+fdt_cmd_nyi(int argc, char *argv[])
+{
+
+	printf("command not yet implemented\n");
+	return (CMD_ERROR);
+}