[U-Boot] [PATCH v3 6/7] Add pxecfg command

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@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

changes in v3: - use GPLv2+ license for the readme - parse and create menu in separate steps - adapt to menu interface changes

common/Makefile | 1 + common/cmd_pxecfg.c | 991 +++++++++++++++++++++++++++++++++++++++++++++++++++ doc/README.pxecfg | 239 +++++++++++++ include/common.h | 3 + 4 files changed, 1234 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 d5bd983..6a56f9f 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..b34ac39 --- /dev/null +++ b/common/cmd_pxecfg.c @@ -0,0 +1,991 @@ +/* + * 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 <linux/list.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 list_head list; +}; + +struct pxecfg { + char *title; + char *default_label; + int timeout; + int prompt; + struct list_head labels; +}; + +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(struct pxecfg_label *label) +{ + 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); +} + +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 pxecfg *cfg, int nest_level); + +static int handle_include(char **c, char *base, + struct pxecfg *cfg, 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, cfg, nest_level); +} + +static int parse_menu(char **c, struct pxecfg *cfg, char *b, int nest_level) +{ + struct token t; + char *s = *c; + int err; + + get_token(c, &t, L_KEYWORD); + + switch (t.type) { + case T_TITLE: + err = parse_sliteral(c, &cfg->title); + + break; + + case T_INCLUDE: + err = handle_include(c, b + strlen(b) + 1, cfg, + 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 pxecfg *cfg, + struct pxecfg_label *label) +{ + struct token t; + char *s; + + s = *c; + + get_token(c, &t, L_KEYWORD); + + switch (t.type) { + case T_DEFAULT: + if (cfg->default_label) + free(cfg->default_label); + + cfg->default_label = strdup(label->name); + + if (!cfg->default_label) + return -ENOMEM; + + 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 pxecfg *cfg) +{ + 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; + } + + list_add_tail(&label->list, &cfg->labels); + + while (1) { + s = *c; + get_token(c, &t, L_KEYWORD); + + err = 0; + switch (t.type) { + case T_MENU: + err = parse_label_menu(c, cfg, 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 pxecfg *cfg, int nest_level) +{ + struct token t; + char *s, *b, *label_name; + int err; + + 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, cfg, b, nest_level); + break; + + case T_TIMEOUT: + err = parse_integer(&p, &cfg->timeout); + break; + + case T_LABEL: + err = parse_label(&p, cfg); + break; + + case T_DEFAULT: + err = parse_sliteral(&p, &label_name); + + if (label_name) { + if (cfg->default_label) + free(cfg->default_label); + + cfg->default_label = label_name; + } + + break; + + case T_PROMPT: + err = parse_integer(&p, &cfg->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 void destroy_pxecfg(struct pxecfg *cfg) +{ + struct list_head *pos, *n; + struct pxecfg_label *label; + + if (cfg->title) + free(cfg->title); + + if (cfg->default_label) + free(cfg->default_label); + + list_for_each_safe(pos, n, &cfg->labels) { + label = list_entry(pos, struct pxecfg_label, list); + + label_destroy(label); + } + + free(cfg); +} + +static struct pxecfg *parse_pxecfg(char *menucfg) +{ + struct pxecfg *cfg; + + cfg = malloc(sizeof(*cfg)); + + if (!cfg) { + printf("Out of memory\n"); + return NULL; + } + + cfg->timeout = 0; + cfg->prompt = 0; + cfg->default_label = NULL; + cfg->title = NULL; + + INIT_LIST_HEAD(&cfg->labels); + + if (parse_pxecfg_top(menucfg, cfg, 1) < 0) { + destroy_pxecfg(cfg); + return NULL; + } + + return cfg; +} + +static struct menu *pxecfg_to_menu(struct pxecfg *cfg) +{ + struct pxecfg_label *label; + struct list_head *pos; + struct menu *m; + int err; + + m = menu_create(cfg->title, cfg->timeout, cfg->prompt, label_print); + + if (!m) + return NULL; + + list_for_each(pos, &cfg->labels) { + label = list_entry(pos, struct pxecfg_label, list); + + if (menu_item_add(m, label->name, label) != 1) { + menu_destroy(m); + return NULL; + } + } + + if (cfg->default_label) { + err = menu_default_set(m, cfg->default_label); + if (err != 1) { + if (err != -ENOENT) { + menu_destroy(m); + return NULL; + } + + printf("Missing default: %s\n", cfg->default_label); + } + } + + return m; +} + +static void boot_unattempted_labels(struct pxecfg *cfg) +{ + struct list_head *pos; + struct pxecfg_label *label; + + list_for_each(pos, &cfg->labels) { + label = list_entry(pos, struct pxecfg_label, list); + + if (!label->attempted) + label_boot(label); + } +} + +static void handle_pxecfg(struct pxecfg *cfg) +{ + void *choice; + struct menu *m; + + m = pxecfg_to_menu(cfg); + if (!m) + return; + + if (menu_get_choice(m, &choice) == 1) + label_boot(choice); + + menu_destroy(m); + + boot_unattempted_labels(cfg); +} + +static int boot_pxecfg(int argc, char * const argv[]) +{ + unsigned long pxecfg_addr; + struct pxecfg *cfg; + 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; + } + + cfg = parse_pxecfg((char *)(pxecfg_addr)); + + if (cfg == NULL) { + printf("Error parsing config file\n"); + return 1; + } + + handle_pxecfg(cfg); + + destroy_pxecfg(cfg); + + 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..5c5f8c7 --- /dev/null +++ b/doc/README.pxecfg @@ -0,0 +1,239 @@ +/* + * 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/. + */ + +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 bd2c1a0..9b60469 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);