diff options
| -rw-r--r-- | docs/specs/fw_cfg.txt | 15 | ||||
| -rw-r--r-- | qemu-options.hx | 7 | ||||
| -rw-r--r-- | vl.c | 33 |
3 files changed, 48 insertions, 7 deletions
diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 74351dd18f..c0e76aaee9 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -216,6 +216,21 @@ the following syntax: where <item_name> is the fw_cfg item name, and <path> is the location on the host file system of a file containing the data to be inserted. +Small enough items may be provided directly as strings on the command +line, using the syntax: + + -fw_cfg [name=]<item_name>,string=<string> + +The terminating NUL character of the content <string> will NOT be +included as part of the fw_cfg item data, which is consistent with +the absence of a NUL terminator for items inserted via the file option. + +Both <item_name> and, if applicable, the content <string> are passed +through by QEMU without any interpretation, expansion, or further +processing. Any such processing (potentially performed e.g., by the shell) +is outside of QEMU's responsibility; as such, using plain ASCII characters +is recommended. + NOTE: Users *SHOULD* choose item names beginning with the prefix "opt/" when using the "-fw_cfg" command line option, to avoid conflicting with item names used internally by QEMU. For instance: diff --git a/qemu-options.hx b/qemu-options.hx index 2485b94b16..edee5f4844 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2724,13 +2724,18 @@ ETEXI DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg, "-fw_cfg [name=]<name>,file=<file>\n" - " add named fw_cfg entry from file\n", + " add named fw_cfg entry from file\n" + "-fw_cfg [name=]<name>,string=<str>\n" + " add named fw_cfg entry from string\n", QEMU_ARCH_ALL) STEXI @item -fw_cfg [name=]@var{name},file=@var{file} @findex -fw_cfg Add named fw_cfg entry from file. @var{name} determines the name of the entry in the fw_cfg file directory exposed to the guest. + +@item -fw_cfg [name=]@var{name},string=@var{str} +Add named fw_cfg entry from string. ETEXI DEF("serial", HAS_ARG, QEMU_OPTION_serial, \ @@ -512,6 +512,10 @@ static QemuOptsList qemu_fw_cfg_opts = { .type = QEMU_OPT_STRING, .help = "Sets the name of the file from which\n" "the fw_cfg blob will be loaded", + }, { + .name = "string", + .type = QEMU_OPT_STRING, + .help = "Sets content of the blob to be inserted from a string", }, { /* end of list */ } }, @@ -2239,11 +2243,16 @@ char *qemu_find_file(int type, const char *name) return NULL; } +static inline bool nonempty_str(const char *str) +{ + return str && *str; +} + static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) { gchar *buf; size_t size; - const char *name, *file; + const char *name, *file, *str; if (opaque == NULL) { error_report("fw_cfg device not available"); @@ -2251,8 +2260,15 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) } name = qemu_opt_get(opts, "name"); file = qemu_opt_get(opts, "file"); - if (name == NULL || *name == '\0' || file == NULL || *file == '\0') { - error_report("invalid argument value"); + str = qemu_opt_get(opts, "string"); + + /* we need name and either a file or the content string */ + if (!(nonempty_str(name) && (nonempty_str(file) || nonempty_str(str)))) { + error_report("invalid argument(s)"); + return -1; + } + if (nonempty_str(file) && nonempty_str(str)) { + error_report("file and string are mutually exclusive"); return -1; } if (strlen(name) > FW_CFG_MAX_FILE_PATH - 1) { @@ -2263,9 +2279,14 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) error_report("WARNING: externally provided fw_cfg item names " "should be prefixed with \"opt/\"!"); } - if (!g_file_get_contents(file, &buf, &size, NULL)) { - error_report("can't load %s", file); - return -1; + if (nonempty_str(str)) { + size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */ + buf = g_memdup(str, size); + } else { + if (!g_file_get_contents(file, &buf, &size, NULL)) { + error_report("can't load %s", file); + return -1; + } } fw_cfg_add_file((FWCfgState *)opaque, name, buf, size); return 0; |