diff options
| author | Gabriel L. Somlo <somlo@cmu.edu> | 2015-04-29 11:21:53 -0400 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2015-06-10 08:06:46 +0200 |
| commit | 81b2b81062612ebeac4cd5333a3b15c7d79a5a3d (patch) | |
| tree | c505eeb49687c998e3f536e8e7fe0fbfbf5303b1 /docs/specs | |
| parent | 0eb973f91521c6bcb6399d25327711d083f6eb10 (diff) | |
| download | qemu-81b2b81062612ebeac4cd5333a3b15c7d79a5a3d.zip | |
fw_cfg: insert fw_cfg file blobs via qemu cmdline
Allow user supplied files to be inserted into the fw_cfg
device before starting the guest. Since fw_cfg_add_file()
already disallows duplicate fw_cfg file names, qemu will
exit with an error message if the user supplies multiple
blobs with the same fw_cfg file name, or if a blob name
collides with a fw_cfg name programmatically added from
within the QEMU source code. A warning message will be
printed if the fw_cfg item name does not begin with the
prefix "opt/", which is recommended for external, user
provided blobs.
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'docs/specs')
| -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(). |