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| author | Gabriel L. Somlo <somlo@cmu.edu> | 2015-10-08 17:02:53 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2015-10-19 15:26:53 +0200 |
| commit | 57c3d238a5ff7e7ad7aba098b5d55d8d89c2a6a1 (patch) | |
| tree | eda4079e6dadb822b9c3f03cb84dcf346406141b /docs/specs/fw_cfg.txt | |
| parent | 6407d76eb4e5b5dd4af8613cef0162f31ff739ed (diff) | |
| download | qemu-57c3d238a5ff7e7ad7aba098b5d55d8d89c2a6a1.zip qemu-57c3d238a5ff7e7ad7aba098b5d55d8d89c2a6a1.tar.gz qemu-57c3d238a5ff7e7ad7aba098b5d55d8d89c2a6a1.tar.bz2 | |
fw_cfg: document fw_cfg_modify_iXX() update functions
Document the behavior of fw_cfg_modify_iXX() for leak-less updating
of integer-type blobs.
Currently only fw_cfg_modify_i16() is coded, but 32- and 64-bit versions
may be added later if necessary..
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/fw_cfg.txt')
| -rw-r--r-- | docs/specs/fw_cfg.txt | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index c0e76aa..d5dee4b 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -159,6 +159,17 @@ will convert a 16-, 32-, or 64-bit integer to little-endian, then add a dynamically allocated copy of the appropriately sized item to fw_cfg under the given selector key value. +== fw_cfg_modify_iXX() == + +Modify the value of an XX-bit item (where XX may be 16, 32, or 64). +Similarly to the corresponding fw_cfg_add_iXX() function set, convert +a 16-, 32-, or 64-bit integer to little endian, create a dynamically +allocated copy of the required size, and replace the existing item at +the given selector key value with the newly allocated one. The previous +item, assumed to have been allocated during an earlier call to +fw_cfg_add_iXX() or fw_cfg_modify_iXX() (of the same width XX), is freed +before the function returns. + == fw_cfg_add_file() == Given a filename (i.e., fw_cfg item name), starting pointer, and size, |