[U-Boot] [PATCH v2 5/6] Add pxecfg command

Jason Hobbs jason.hobbs at calxeda.com
Thu Jun 23 20:27:34 CEST 2011


Add pxecfg command, which is intended to mimic PXELINUX functionality.
'pxecfg get' uses tftp to retrieve a file based on UUID, MAC address or
IP address. 'pxecfg boot' interprets the contents of PXELINUX config
like file to boot using a specific initrd, kernel and kernel command
line.

This patch also adds a README.pxecfg file - see it for more details on
the pxecfg command.

Signed-off-by: Jason Hobbs <jason.hobbs at calxeda.com>
---
changes in v2:
- call abortboot directly instead of via a wrapper
- change the license to GPLv2+
- cleanup brace usage in multiline statements, conditionals
- allow bootfile to not exist, or to be a standalone filename
- try to clarify what's going on with get_relfile
- try cfg paths one by one instead of building an array
- refactor getenv/printfs to a new from_env function
- use the new generic menu code instead of that being integrated
- drop the ifdef from do_tftp in common.h
- use a clearer comment wrt to localcmd dup
- default to no timeout

 common/Makefile     |    1 +
 common/cmd_pxecfg.c |  924 +++++++++++++++++++++++++++++++++++++++++++++++++++
 doc/README.pxecfg   |  238 +++++++++++++
 include/common.h    |    3 +
 4 files changed, 1166 insertions(+), 0 deletions(-)
 create mode 100644 common/cmd_pxecfg.c
 create mode 100644 doc/README.pxecfg

diff --git a/common/Makefile b/common/Makefile
index 9b413cd..8885c6d 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -136,6 +136,7 @@ COBJS-$(CONFIG_CMD_PCI) += cmd_pci.o
 endif
 COBJS-y += cmd_pcmcia.o
 COBJS-$(CONFIG_CMD_PORTIO) += cmd_portio.o
+COBJS-$(CONFIG_CMD_PXECFG) += cmd_pxecfg.o
 COBJS-$(CONFIG_CMD_REGINFO) += cmd_reginfo.o
 COBJS-$(CONFIG_CMD_REISER) += cmd_reiser.o
 COBJS-$(CONFIG_CMD_SATA) += cmd_sata.o
diff --git a/common/cmd_pxecfg.c b/common/cmd_pxecfg.c
new file mode 100644
index 0000000..b44db8c
--- /dev/null
+++ b/common/cmd_pxecfg.c
@@ -0,0 +1,924 @@
+/*
+ * Copyright 2010-2011 Calxeda, Inc.
+ *
+ * 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 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <common.h>
+#include <command.h>
+#include <malloc.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <errno.h>
+
+#include "menu.h"
+
+#define MAX_TFTP_PATH_LEN 127
+
+static char *from_env(char *envvar)
+{
+	char *ret;
+
+	ret = getenv(envvar);
+
+	if (!ret)
+		printf("missing environment variable: %s\n", envvar);
+
+	return ret;
+}
+
+/*
+ * Returns the ethaddr environment variable formated with -'s instead of :'s
+ */
+static void format_mac_pxecfg(char **outbuf)
+{
+	char *p, *ethaddr;
+
+	*outbuf = NULL;
+
+	ethaddr = from_env("ethaddr");
+
+	if (!ethaddr)
+		return;
+
+	*outbuf = strdup(ethaddr);
+
+	if (*outbuf == NULL)
+		return;
+
+	for (p = *outbuf; *p; p++) {
+		if (*p == ':')
+			*p = '-';
+	}
+}
+
+/*
+ * Returns the directory the file specified in the bootfile env variable is
+ * in.
+ */
+static char *get_bootfile_path(void)
+{
+	char *bootfile, *bootfile_path, *last_slash;
+	size_t path_len;
+
+	bootfile = from_env("bootfile");
+
+	if (!bootfile)
+		return NULL;
+
+	last_slash = strrchr(bootfile, '/');
+
+	if (last_slash == NULL)
+		return NULL;
+
+	path_len = (last_slash - bootfile) + 1;
+
+	bootfile_path = malloc(path_len + 1);
+
+	if (bootfile_path == NULL) {
+		printf("out of memory\n");
+		return NULL;
+	}
+
+	strncpy(bootfile_path, bootfile, path_len);
+
+	bootfile_path[path_len] = '\0';
+
+	return bootfile_path;
+}
+
+/*
+ * As in pxelinux, paths to files in pxecfg files are relative to the location
+ * of bootfile. get_relfile takes a path from a pxecfg file and joins it with
+ * the bootfile path to get the full path to the target file.
+ */
+static int get_relfile(char *file_path, void *file_addr)
+{
+	char *bootfile_path;
+	size_t path_len;
+	char relfile[MAX_TFTP_PATH_LEN+1];
+	char addr_buf[10];
+	char *tftp_argv[] = {"tftp", NULL, NULL, NULL};
+
+	bootfile_path = get_bootfile_path();
+
+	path_len = strlen(file_path);
+
+	if (bootfile_path)
+		path_len += strlen(bootfile_path);
+
+	if (path_len > MAX_TFTP_PATH_LEN) {
+		printf("Base path too long (%s%s)\n",
+					bootfile_path ? bootfile_path : "",
+					file_path);
+
+		if (bootfile_path)
+			free(bootfile_path);
+
+		return -ENAMETOOLONG;
+	}
+
+	sprintf(relfile, "%s%s",
+			bootfile_path ? bootfile_path : "",
+			file_path);
+
+	if (bootfile_path)
+		free(bootfile_path);
+
+	printf("Retreiving file: %s\n", relfile);
+
+	sprintf(addr_buf, "%p", file_addr);
+
+	tftp_argv[1] = addr_buf;
+	tftp_argv[2] = relfile;
+
+	if (do_tftpb(NULL, 0, 3, tftp_argv)) {
+		printf("File not found\n");
+		return -ENOENT;
+	}
+
+	return 1;
+}
+
+static int get_pxecfg_file(char *file_path, void *file_addr)
+{
+	unsigned long config_file_size;
+	int err;
+
+	err = get_relfile(file_path, file_addr);
+
+	if (err < 0)
+		return err;
+
+	config_file_size = simple_strtoul(getenv("filesize"), NULL, 16);
+	*(char *)(file_addr + config_file_size) = '\0';
+
+	return 1;
+}
+
+static int get_pxelinux_path(char *file, void *pxecfg_addr)
+{
+	size_t base_len = strlen("pxelinux.cfg/");
+	char path[MAX_TFTP_PATH_LEN+1];
+
+	if (base_len + strlen(file) > MAX_TFTP_PATH_LEN) {
+		printf("path too long, skipping\n");
+		return -ENAMETOOLONG;
+	}
+
+	sprintf(path, "pxelinux.cfg/%s", file);
+
+	return get_pxecfg_file(path, pxecfg_addr);
+}
+
+static int pxecfg_uuid_path(void *pxecfg_addr)
+{
+	char *uuid_str;
+
+	uuid_str = from_env("pxeuuid");
+
+	if (!uuid_str)
+		return -ENOENT;
+
+	return get_pxelinux_path(uuid_str, pxecfg_addr);
+}
+
+static int pxecfg_mac_path(void *pxecfg_addr)
+{
+	char *mac_str = NULL;
+
+	format_mac_pxecfg(&mac_str);
+
+	if (!mac_str)
+		return -ENOENT;
+
+	return get_pxelinux_path(mac_str, pxecfg_addr);
+}
+
+static int pxecfg_ipaddr_paths(void *pxecfg_addr)
+{
+	char ip_addr[9];
+	int mask_pos, err;
+
+	sprintf(ip_addr, "%08X", ntohl(NetOurIP));
+
+	for (mask_pos = 7; mask_pos >= 0;  mask_pos--) {
+		err = get_pxelinux_path(ip_addr, pxecfg_addr);
+
+		if (err > 0)
+			return err;
+
+		ip_addr[mask_pos] = '\0';
+	}
+
+	return -ENOENT;
+}
+
+/*
+ * Follows pxelinux's rules to download a pxecfg file from a tftp server.  The
+ * file is stored at the location given by the pxecfg_addr environment
+ * variable, which must be set.
+ *
+ * UUID comes from pxeuuid env variable, if defined
+ * MAC addr comes from ethaddr env variable, if defined
+ * IP
+ *
+ * see http://syslinux.zytor.com/wiki/index.php/PXELINUX
+ */
+static int get_pxecfg(int argc, char * const argv[])
+{
+	char *pxecfg_ram;
+	void *pxecfg_addr;
+
+	pxecfg_ram = from_env("pxecfg_ram");
+
+	if (!pxecfg_ram)
+		return 1;
+
+	pxecfg_addr = (void *)simple_strtoul(pxecfg_ram, NULL, 16);
+
+	if (pxecfg_uuid_path(pxecfg_addr) > 0
+		|| pxecfg_mac_path(pxecfg_addr) > 0
+		|| pxecfg_ipaddr_paths(pxecfg_addr) > 0
+		|| get_pxelinux_path("default", pxecfg_addr) > 0) {
+
+		printf("Config file found\n");
+
+		return 1;
+	}
+
+	printf("Config file not found\n");
+
+	return 0;
+}
+
+static int get_relfile_envaddr(char *file_path, char *envaddr_name)
+{
+	void *file_addr;
+	char *envaddr;
+
+	envaddr = from_env(envaddr_name);
+
+	if (!envaddr)
+		return -ENOENT;
+
+	file_addr = (void *)simple_strtoul(envaddr, NULL, 16);
+
+	return get_relfile(file_path, file_addr);
+}
+
+struct pxecfg_label {
+	char *name;
+	char *kernel;
+	char *append;
+	char *initrd;
+	int attempted;
+	int localboot;
+};
+
+struct pxecfg_label *label_create(void)
+{
+	struct pxecfg_label *label;
+
+	label = malloc(sizeof *label);
+
+	if (!label)
+		return NULL;
+
+	label->name = NULL;
+	label->kernel = NULL;
+	label->append = NULL;
+	label->initrd = NULL;
+	label->localboot = 0;
+	label->attempted = 0;
+
+	return label;
+}
+
+static void label_destroy(void *data)
+{
+	struct pxecfg_label *label = data;
+
+	if (label->name)
+		free(label->name);
+
+	if (label->kernel)
+		free(label->kernel);
+
+	if (label->append)
+		free(label->append);
+
+	if (label->initrd)
+		free(label->initrd);
+
+	free(label);
+}
+
+static void label_print(void *data)
+{
+	struct pxecfg_label *label = data;
+
+	printf("Label: %s\n", label->name);
+
+	if (label->kernel)
+		printf("\tkernel: %s\n", label->kernel);
+
+	if (label->append)
+		printf("\tappend: %s\n", label->append);
+
+	if (label->initrd)
+		printf("\tinitrd: %s\n", label->initrd);
+}
+
+static int label_localboot(struct pxecfg_label *label)
+{
+	char *localcmd, *dupcmd;
+	int ret;
+
+	localcmd = from_env("localcmd");
+
+	if (!localcmd)
+		return -ENOENT;
+
+	/*
+	 * dup the command to avoid any issues with the version of it existing
+	 * in the environment changing during the execution of the command.
+	 */
+	dupcmd = strdup(localcmd);
+
+	if (!dupcmd) {
+		printf("out of memory\n");
+		return -ENOMEM;
+	}
+
+	if (label->append)
+		setenv("bootargs", label->append);
+
+	printf("running: %s\n", dupcmd);
+
+	ret = run_command2(dupcmd, 0);
+
+	free(dupcmd);
+
+	return ret;
+}
+
+/*
+ * Do what it takes to boot a chosen label.
+ *
+ * Retreive the kernel and initrd, and prepare bootargs.
+ */
+static void label_boot(struct pxecfg_label *label)
+{
+	char *bootm_argv[] = { "bootm", NULL, NULL, NULL, NULL };
+
+	label_print(label);
+
+	label->attempted = 1;
+
+	if (label->localboot) {
+		label_localboot(label);
+		return;
+	}
+
+	if (label->kernel == NULL) {
+		printf("No kernel given, skipping label\n");
+		return;
+	}
+
+	if (label->initrd) {
+		if (get_relfile_envaddr(label->initrd, "initrd_ram") < 0) {
+			printf("Skipping label\n");
+			return;
+		}
+
+		bootm_argv[2] = getenv("initrd_ram");
+	} else {
+		bootm_argv[2] = "-";
+	}
+
+	if (get_relfile_envaddr(label->kernel, "kernel_ram") < 0) {
+		printf("Skipping label\n");
+		return;
+	}
+
+	if (label->append)
+		setenv("bootargs", label->append);
+
+	bootm_argv[1] = getenv("kernel_ram");
+
+	/*
+	 * fdt usage is optional - if unset, this stays NULL.
+	 */
+	bootm_argv[3] = getenv("fdtaddr");
+
+	do_bootm(NULL, 0, 4, bootm_argv);
+}
+
+static void *label_boot_unattempted(void *data, void *extra)
+{
+	struct pxecfg_label *label = data;
+
+	if (!label->attempted)
+		label_boot(label);
+
+	return NULL;
+}
+
+enum token_type {
+	T_EOL,
+	T_STRING,
+	T_EOF,
+	T_MENU,
+	T_TITLE,
+	T_TIMEOUT,
+	T_LABEL,
+	T_KERNEL,
+	T_APPEND,
+	T_INITRD,
+	T_LOCALBOOT,
+	T_DEFAULT,
+	T_PROMPT,
+	T_INCLUDE,
+	T_INVALID
+};
+
+struct token {
+	char *val;
+	enum token_type type;
+};
+
+enum lex_state {
+	L_NORMAL = 0,
+	L_KEYWORD,
+	L_SLITERAL
+};
+
+static const struct token keywords[] = {
+	{"menu", T_MENU},
+	{"title", T_TITLE},
+	{"timeout", T_TIMEOUT},
+	{"default", T_DEFAULT},
+	{"prompt", T_PROMPT},
+	{"label", T_LABEL},
+	{"kernel", T_KERNEL},
+	{"localboot", T_LOCALBOOT},
+	{"append", T_APPEND},
+	{"initrd", T_INITRD},
+	{"include", T_INCLUDE},
+	{NULL, T_INVALID}
+};
+
+static char *get_string(char **p, struct token *t, char delim, int lower)
+{
+	char *b, *e;
+	size_t len, i;
+
+	b = e = *p;
+
+	while (*e) {
+		if ((delim == ' ' && isspace(*e)) || delim == *e)
+			break;
+		e++;
+	}
+
+	len = e - b;
+
+	t->val = malloc(len + 1);
+	if (!t->val) {
+		printf("out of memory\n");
+		return NULL;
+	}
+
+	for (i = 0; i < len; i++, b++) {
+		if (lower)
+			t->val[i] = tolower(*b);
+		else
+			t->val[i] = *b;
+	}
+
+	t->val[len] = '\0';
+
+	*p = e;
+
+	t->type = T_STRING;
+
+	return t->val;
+}
+
+static void get_keyword(struct token *t)
+{
+	int i;
+
+	for (i = 0; keywords[i].val; i++) {
+		if (!strcmp(t->val, keywords[i].val)) {
+			t->type = keywords[i].type;
+			break;
+		}
+	}
+}
+
+static void get_token(char **p, struct token *t, enum lex_state state)
+{
+	char *c = *p;
+
+	t->type = T_INVALID;
+
+	/* eat non EOL whitespace */
+	while (*c == ' ' || *c == '\t')
+		c++;
+
+	/* eat comments */
+	if (*c == '#') {
+		while (*c && *c != '\n')
+			c++;
+	}
+
+	if (*c == '\n') {
+		t->type = T_EOL;
+		c++;
+	} else if (*c == '\0') {
+		t->type = T_EOF;
+		c++;
+	} else if (state == L_SLITERAL) {
+		get_string(&c, t, '\n', 0);
+	} else if (state == L_KEYWORD) {
+		get_string(&c, t, ' ', 1);
+		get_keyword(t);
+	}
+
+	*p = c;
+}
+
+static void eol_or_eof(char **c)
+{
+	while (**c && **c != '\n')
+		(*c)++;
+}
+
+static int parse_sliteral(char **c, char **dst)
+{
+	struct token t;
+	char *s = *c;
+
+	get_token(c, &t, L_SLITERAL);
+
+	if (t.type != T_STRING) {
+		printf("Expected string literal: %.*s\n", (int)(*c - s), s);
+		return -EINVAL;
+	}
+
+	*dst = t.val;
+
+	return 1;
+}
+
+static int parse_integer(char **c, int *dst)
+{
+	struct token t;
+	char *s = *c;
+
+	get_token(c, &t, L_SLITERAL);
+
+	if (t.type != T_STRING) {
+		printf("Expected string: %.*s\n", (int)(*c - s), s);
+		return -EINVAL;
+	}
+
+	*dst = (int)simple_strtoul(t.val, NULL, 10);
+
+	free(t.val);
+
+	return 1;
+}
+
+static int parse_pxecfg_top(char *p, struct menu *m, int nest_level);
+
+static int handle_include(char **c, char *base, struct menu *m, int nest_level)
+{
+	char *include_path;
+	int err;
+
+	err = parse_sliteral(c, &include_path);
+
+	if (err < 0) {
+		printf("Expected include path\n");
+		return err;
+	}
+
+	err = get_pxecfg_file(include_path, base);
+
+	if (err < 0) {
+		printf("Couldn't get %s\n", include_path);
+		return err;
+	}
+
+	return parse_pxecfg_top(base, m, nest_level);
+}
+
+static int parse_menu(char **c, struct menu *m, char *b, int nest_level)
+{
+	struct token t;
+	char *s = *c, *title;
+	int err;
+
+	get_token(c, &t, L_KEYWORD);
+
+	switch (t.type) {
+	case T_TITLE:
+		err = parse_sliteral(c, &title);
+
+		if (title) {
+			menu_title_set(m, title);
+			free(title);
+		}
+
+		break;
+
+	case T_INCLUDE:
+		err = handle_include(c, b + strlen(b) + 1, m,
+						nest_level + 1);
+		break;
+
+	default:
+		printf("Ignoring malformed menu command: %.*s\n",
+				(int)(*c - s), s);
+	}
+
+	if (err < 0)
+		return err;
+
+	eol_or_eof(c);
+
+	return 1;
+}
+
+static int parse_label_menu(char **c, struct menu *m,
+				struct pxecfg_label *label)
+{
+	struct token t;
+	char *s;
+
+	s = *c;
+
+	get_token(c, &t, L_KEYWORD);
+
+	switch (t.type) {
+	case T_DEFAULT:
+		menu_default_set(m, label->name);
+		break;
+	default:
+		printf("Ignoring malformed menu command: %.*s\n",
+				(int)(*c - s), s);
+	}
+
+	eol_or_eof(c);
+
+	return 0;
+}
+
+static int parse_label(char **c, struct menu *m)
+{
+	struct token t;
+	char *s;
+	struct pxecfg_label *label;
+	int err;
+
+	label = label_create();
+	if (!label)
+		return -ENOMEM;
+
+	err = parse_sliteral(c, &label->name);
+	if (err < 0) {
+		printf("Expected label name\n");
+		label_destroy(label);
+		return -EINVAL;
+	}
+
+	err = menu_item_add(m, label->name, label);
+	if (err < 0) {
+		label_destroy(label);
+		return err;
+	}
+
+	while (1) {
+		s = *c;
+		get_token(c, &t, L_KEYWORD);
+
+		err = 0;
+		switch (t.type) {
+		case T_MENU:
+			err = parse_label_menu(c, m, label);
+			break;
+
+		case T_KERNEL:
+			err = parse_sliteral(c, &label->kernel);
+			break;
+
+		case T_APPEND:
+			err = parse_sliteral(c, &label->append);
+			break;
+
+		case T_INITRD:
+			err = parse_sliteral(c, &label->initrd);
+			break;
+
+		case T_LOCALBOOT:
+			err = parse_integer(c, &label->localboot);
+			break;
+
+		case T_EOL:
+			break;
+
+		/*
+		 * A label ends when we either get to the end of a file, or
+		 * get some input we otherwise don't have a handler defined
+		 * for.
+		 */
+		default:
+			/* put it back */
+			*c = s;
+			return 1;
+		}
+
+		if (err < 0)
+			return err;
+	}
+}
+
+#define MAX_NEST_LEVEL 16
+
+static int parse_pxecfg_top(char *p, struct menu *m, int nest_level)
+{
+	struct token t;
+	char *s, *b, *label_name;
+	int err, prompt, timeout;
+
+	b = p;
+
+	if (nest_level > MAX_NEST_LEVEL) {
+		printf("Maximum nesting exceeded\n");
+		return -EMLINK;
+	}
+
+	while (1) {
+		s = p;
+
+		get_token(&p, &t, L_KEYWORD);
+
+		err = 0;
+		switch (t.type) {
+		case T_MENU:
+			err = parse_menu(&p, m, b, nest_level);
+			break;
+
+		case T_TIMEOUT:
+			err = parse_integer(&p, &timeout);
+			menu_timeout_set(m, timeout);
+			break;
+
+		case T_LABEL:
+			err = parse_label(&p, m);
+			break;
+
+		case T_DEFAULT:
+			err = parse_sliteral(&p, &label_name);
+
+			if (label_name) {
+				menu_default_set(m, label_name);
+				free(label_name);
+			}
+
+			break;
+
+		case T_PROMPT:
+			err = parse_integer(&p, &prompt);
+			menu_prompt_set(m, prompt);
+			break;
+
+		case T_EOL:
+			break;
+
+		case T_EOF:
+			return 1;
+
+		default:
+			printf("Ignoring unknown command: %.*s\n",
+							(int)(p - s), s);
+			eol_or_eof(&p);
+		}
+
+		if (err < 0)
+			return err;
+	}
+}
+
+static struct menu *parse_pxecfg(char *menucfg)
+{
+	struct menu *m;
+
+	m = menu_create(label_print, label_destroy);
+
+	if (!m)
+		return NULL;
+
+	if (parse_pxecfg_top(menucfg, m, 1) < 0) {
+		menu_destroy(m);
+		return NULL;
+	}
+
+	return m;
+}
+
+static void handle_pxecfg(struct menu *m)
+{
+	struct pxecfg_label *label = NULL;
+
+	if (menu_should_prompt(m)) {
+		label = menu_user_choice(m);
+
+		if (label)
+			label_boot(label);
+
+		return;
+	}
+
+	label = menu_default_choice(m);
+
+	if (label) {
+		printf("Attempting to boot from default label: %s\n",
+					label->name);
+
+		label_boot(label);
+	}
+
+	menu_items_data_iter(m, label_boot_unattempted, NULL);
+}
+
+static int boot_pxecfg(int argc, char * const argv[])
+{
+	unsigned long pxecfg_addr;
+	struct menu *menu;
+	char *pxecfg_ram;
+
+	if (argc == 2) {
+		pxecfg_ram = from_env("pxecfg_ram");
+		if (!pxecfg_ram)
+			return 1;
+
+		pxecfg_addr = simple_strtoul(pxecfg_ram, NULL, 16);
+	} else if (argc == 3) {
+		pxecfg_addr = simple_strtoul(argv[2], NULL, 16);
+	} else {
+		printf("Invalid number of arguments\n");
+		return 1;
+	}
+
+	menu = parse_pxecfg((char *)(pxecfg_addr));
+
+	if (menu == NULL) {
+		printf("Error parsing config file\n");
+		return 1;
+	}
+
+	handle_pxecfg(menu);
+
+	menu_destroy(menu);
+
+	return 0;
+}
+
+int do_pxecfg(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	if (argc < 2) {
+		printf("pxecfg requires at least one argument\n");
+		return EINVAL;
+	}
+
+	if (!strcmp(argv[1], "get"))
+		return get_pxecfg(argc, argv);
+
+	if (!strcmp(argv[1], "boot"))
+		return boot_pxecfg(argc, argv);
+
+	printf("Invalid pxecfg command: %s\n", argv[1]);
+
+	return EINVAL;
+}
+
+U_BOOT_CMD(
+	pxecfg, 2, 1, do_pxecfg,
+	"commands to get and boot from pxecfg files",
+	"get - try to retrieve a pxecfg file using tftp\npxecfg "
+	"boot [pxecfg_addr] - boot from the pxecfg file at pxecfg_addr\n"
+);
diff --git a/doc/README.pxecfg b/doc/README.pxecfg
new file mode 100644
index 0000000..57abef8
--- /dev/null
+++ b/doc/README.pxecfg
@@ -0,0 +1,238 @@
+/*
+ * Copyright 2010-2011 Calxeda, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+The pxecfg commands provide a near subset of the functionality provided by
+the PXELINUX boot loader. This allows U-boot based systems to be controlled
+remotely using the same PXE based techniques that many non U-boot based servers
+use. To avoid identity confusion with PXELINUX, and because not all behavior is
+identical, we call this feature 'pxecfg'.
+
+Commands
+========
+
+pxecfg get
+----------
+     syntax: pxecfg get
+
+     follows PXELINUX's rules for retrieving configuration files from a tftp
+     server, and supports a subset of PXELINUX's config file syntax.
+
+     Environment
+     -----------
+     get_pxecfg requires two environment variables to be set:
+
+     pxecfg_ram - should be set to a location in RAM large enough to hold
+     pxecfg files while they're being processed. Up to 16 config files may be
+     held in memory at once. The exact number and size of the files varies with
+     how the system is being used. A typical config file is a few hundred bytes
+     long.
+
+     bootfile,serverip - these two are typically set in the DHCP response
+     handler, and correspond to fields in the DHCP response.
+
+     get_pxecfg optionally supports these two environment variables being set:
+
+     ethaddr - this is the standard MAC address for the ethernet adapter in use.
+     getpxe_cfg uses it to look for a configuration file specific to a system's
+     MAC address.
+
+     pxeuuid - this is a UUID in standard form using lower case hexadecimal
+     digits, for example, 550e8400-e29b-41d4-a716-446655440000. get_pxecfg uses
+     it to look for a configuration file based on the system's UUID.
+
+     File Paths
+     ----------
+     get_pxecfg repeatedly tries to download config files until it either
+     successfully downloads one or runs out of paths to try. The order and
+     contents of paths it tries mirrors exactly that of PXELINUX - you can read
+     in more detail about it at:
+
+     http://syslinux.zytor.com/wiki/index.php/Doc/pxelinux
+
+pxecfg boot
+-----------
+     syntax: pxecfg boot [pxecfg_addr]
+
+     Interprets a pxecfg file stored in memory.
+
+     pxecfg_addr is an optional argument giving the location of the pxecfg file
+
+     Environment
+     -----------
+     There are some environment variables that may need to be set, depending on
+     conditions.
+
+     pxecfg_ram - if the optional argument pxecfg_addr is not supplied, an
+     environment variable named pxecfg_ram must be supplied. This is typically
+     the same value as is used for the get_pxecfg command.
+
+     bootfile - typically set in the DHCP response handler based on the same
+     field in the DHCP respone, this path is used to generate the base directory
+     that all other paths to files retrieved by boot_pxecfg will use.
+
+     serverip - typically set in the DHCP response handler, this is the IP
+     address of the tftp server from which other files will be retrieved.
+
+     kernel_ram,initrd_ram - locations in RAM at which boot_pxecfg will store
+     the kernel and initrd it retrieves from tftp. These locations will be
+     passed to the bootm command to boot the kernel. These environment variables
+     are required to be set.
+
+     fdtaddr - the location of a fdt blob. If this is set, it will be passed to
+     bootm when booting a kernel.
+
+pxecfg file format
+==================
+The pxecfg file format is more or less a subset of the PXELINUX file format, see
+http://syslinux.zytor.com/wiki/index.php/PXELINUX. It's composed of one line
+commands - global commands, and commands specific to labels. Lines begining with
+# are treated as comments. White space between and at the beginning of lines is
+ignored.
+
+The size of pxecfg files and the number of labels is only limited by the amount
+of RAM available to U-boot. Memory for labels is dynamically allocated as
+they're parsed, and memory for pxecfg files is statically allocated, and its
+location is given by the pxecfg_ram environment variable. the pxecfg code is
+not aware of the size of the pxecfg memory and will outgrow it if pxecfg files
+are too large.
+
+Supported global commands
+-------------------------
+Unrecognized commands are ignored.
+
+default <label>     - the label named here is treated as the default and is
+                      the first label boot_pxecfg attempts to boot.
+
+menu title <string> - sets a title for the menu of labels being displayed.
+
+menu include <path> - use tftp to retrieve the pxecfg file at <path>, which
+                      is then immediately parsed as if the start of its
+                      contents were the next line in the current file. nesting
+                      of include up to 16 files deep is supported.
+
+prompt <flag>       - if 1, always prompt the user to enter a label to boot
+                      from. if 0, only prompt the user if timeout expires.
+
+timeout <num>	    - wait for user input for <num>/10 seconds before
+                      auto-booting a node.
+
+label <name>        - begin a label definition. labels continue until
+                      a command not recognized as a label command is seen,
+                      or EOF is reached.
+
+Supported label commands
+------------------------
+labels end when a command not recognized as a label command is reached, or EOF.
+
+menu default        - set this label as the default label to boot; this is
+                      the same behavior as the global default command but
+                      specified in a different way
+
+kernel <path>       - if this label is chosen, use tftp to retrieve the kernel
+                      at <path>. it will be stored at the address indicated in
+                      the kernel_ram environment variable, and that address
+                      will be passed to bootm to boot this kernel.
+
+append <string>     - use <string> as the kernel command line when booting this
+                      label.
+
+initrd <path>       - if this label is chosen, use tftp to retrieve the initrd
+                      at <path>. it will be stored at the address indicated in
+                      the initrd_ram environment variable, and that address
+                      will be passed to bootm.
+
+localboot <flag>    - Run the command defined by "localcmd" in the environment.
+                      <flag> is ignored and is only here to match the syntax of
+                      PXELINUX config files.
+
+Example
+-------
+Here's a couple of example files to show how this works.
+
+------------/tftpboot/pxelinux.cfg/menus/linux.list----------
+menu title Linux selections
+
+# This is the default label
+label install
+	menu label Default Install Image
+	kernel kernels/install.bin
+	append console=ttyAMA0,38400 debug earlyprintk
+	initrd initrds/uzInitrdDebInstall
+
+# Just another label
+label linux-2.6.38
+	kernel kernels/linux-2.6.38.bin
+	append root=/dev/sdb1
+
+# The locally installed kernel
+label local
+	menu label Locally installed kernel
+	append root=/dev/sdb1
+	localboot 1
+-------------------------------------------------------------
+
+------------/tftpboot/pxelinux.cfg/default-------------------
+menu include pxelinux.cfg/menus/base.menu
+timeout 500
+
+default linux-2.6.38
+-------------------------------------------------------------
+
+When a pxecfg client retrieves and boots the default pxecfg file,
+boot_pxecfg will wait for user input for 5 seconds before booting
+the linux-2.6.38 label, which will cause /tftpboot/kernels/linux-2.6.38.bin
+to be downloaded, and boot with the command line "root=/dev/sdb1"
+
+Differences with PXELINUX
+=========================
+The biggest difference between pxecfg and PXELINUX is that since pxecfg
+is part of U-boot and is written entirely in C, it can run on platform
+with network support in U-boot.  Here are some of the other differences
+between PXELINUX and pxecfg.
+
+- pxecfg does not support the PXELINUX DHCP option codes specified in
+  RFC 5071, but could be extended to do so.
+
+- when pxecfg fails to boot, it will return control to U-boot, allowing
+  another command to run, other U-boot command, instead of resetting the
+  machine like PXELINUX.
+
+- pxecfg doesn't rely on or provide an UNDI/PXE stack in memory, it only
+  uses U-boot.
+
+- pxecfg doesn't provide the full menu implementation that PXELINUX
+  does, only a simple text based menu using the commands described in
+  this README.  With PXELINUX, it's possible to have a graphical boot
+  menu, submenus, passwords, etc. pxecfg could be extended to support
+  a more robust menuing system like that of PXELINUX's.
+
+- pxecfg expects U-boot uimg's as kernels.  anything that would work with
+  the 'bootm' command in U-boot could work with pxecfg.
+
+- pxecfg doesn't recognize initrd options in the append command - you must
+  specify initrd files using the initrd command
+
+- pxecfg only recognizes a single file on the initrd command line.  it
+  could be extended to support multiple
+
+- in pxecfg, the localboot command doesn't necessarily cause a local
+  disk boot - it will do whatever is defined in the 'localcmd' env
+  variable. And since it doesn't support a full UNDI/PXE stack, the
+  type field is ignored.
+
+- the interactive prompt in pxecfg only allows you to choose a label from
+  the menu.  if you want to boot something not listed, you can ctrl+c out
+  of pxecfg and use existing U-boot commands to accomplish it.
diff --git a/include/common.h b/include/common.h
index d8b8a79..a28abe1 100644
--- a/include/common.h
+++ b/include/common.h
@@ -259,6 +259,9 @@ extern ulong load_addr;		/* Default Load Address */
 /* common/cmd_doc.c */
 void	doc_probe(unsigned long physadr);
 
+/* common/cmd_net.c */
+int do_tftpb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+
 /* common/cmd_nvedit.c */
 int	env_init     (void);
 void	env_relocate (void);
-- 
1.7.0.4



More information about the U-Boot mailing list