diff options
Diffstat (limited to 'docs/specs/fw_cfg.txt')
| -rw-r--r-- | docs/specs/fw_cfg.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 6accd924bd..74351dd18f 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -203,3 +203,24 @@ completes fully overwriting the item's data. NOTE: This function is deprecated, and will be completely removed starting with QEMU v2.4. + +== Externally Provided Items == + +As of v2.4, "file" fw_cfg items (i.e., items with selector keys above +FW_CFG_FILE_FIRST, and with a corresponding entry in the fw_cfg file +directory structure) may be inserted via the QEMU command line, using +the following syntax: + + -fw_cfg [name=]<item_name>,file=<path> + +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. + +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: + + -fw_cfg name=opt/my_item_name,file=./my_blob.bin + +Similarly, QEMU developers *SHOULD NOT* use item names prefixed with +"opt/" when inserting items programmatically, e.g. via fw_cfg_add_file(). |