diff options
Diffstat (limited to '')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg b/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg index 011dda4f8e8a..54d1bfd0db12 100644 --- a/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg +++ b/Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg @@ -12,10 +12,11 @@ Description: configuration data to the guest userspace. The authoritative guest-side hardware interface documentation - to the fw_cfg device can be found in "docs/specs/fw_cfg.txt" - in the QEMU source tree. + to the fw_cfg device can be found in "docs/specs/fw_cfg.rst" + in the QEMU source tree, or online at: + https://qemu-project.gitlab.io/qemu/specs/fw_cfg.html - === SysFS fw_cfg Interface === + **SysFS fw_cfg Interface** The fw_cfg sysfs interface described in this document is only intended to display discoverable blobs (i.e., those registered @@ -31,7 +32,7 @@ Description: /sys/firmware/qemu_fw_cfg/rev - --- Discoverable fw_cfg blobs by selector key --- + **Discoverable fw_cfg blobs by selector key** All discoverable blobs listed in the fw_cfg file directory are displayed as entries named after their unique selector key @@ -45,24 +46,26 @@ Description: Each such fw_cfg sysfs entry has the following values exported as attributes: - name : The 56-byte nul-terminated ASCII string used as the + ==== ==================================================== + name The 56-byte nul-terminated ASCII string used as the blob's 'file name' in the fw_cfg directory. - size : The length of the blob, as given in the fw_cfg + size The length of the blob, as given in the fw_cfg directory. - key : The value of the blob's selector key as given in the + key The value of the blob's selector key as given in the fw_cfg directory. This value is the same as used in the parent directory name. - raw : The raw bytes of the blob, obtained by selecting the + raw The raw bytes of the blob, obtained by selecting the entry via the control register, and reading a number of bytes equal to the blob size from the data register. + ==== ==================================================== - --- Listing fw_cfg blobs by file name --- + **Listing fw_cfg blobs by file name** While the fw_cfg device does not impose any specific naming convention on the blobs registered in the file directory, QEMU developers have traditionally used path name semantics - to give each blob a descriptive name. For example: + to give each blob a descriptive name. For example:: "bootorder" "genroms/kvmvapic.bin" @@ -81,7 +84,7 @@ Description: of directories matching the path name components of fw_cfg blob names, ending in symlinks to the by_key entry for each "basename", as illustrated below (assume current directory is - /sys/firmware): + /sys/firmware):: qemu_fw_cfg/by_name/bootorder -> ../by_key/38 qemu_fw_cfg/by_name/etc/e820 -> ../../by_key/35 |