[Xen-devel] [MULTIBOOT2 DOC PATCH 02/10] multiboot2: Clarify meaning of information request header tag

[Daniel Kiper <daniel.kiper@xxxxxxxxxx>]

Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
---
 doc/multiboot.texi |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/doc/multiboot.texi b/doc/multiboot.texi
index 27e5a2f..a7e3584 100644
--- a/doc/multiboot.texi
+++ b/doc/multiboot.texi
@@ -443,15 +443,19 @@ u32[n]  | mbi_tag_types     |
 @end group
 @end example
 
-@samp{mbi_tag_types} is an array of u32 each one representing an information
-request
-If this tag is present and @samp{optional} is set to @samp{0} information
-conveyed by requested tag types must be present. If bootloader is unable
-to supply this information it must fail with an error
+@samp{mbi_tag_types} is an array of u32 each one representing an information 
request.
 
-Note: it doesn't garantee that any tags of type @samp{mbi_tag_types} will
-actually be present. E.g. on a videoless system even if you requested tag
-@samp{8} no tags of type @samp{8} will be present in mbi.
+If this tag is present and @samp{optional} is set to @samp{0} bootloader must
+support (understand meaning of) requested tag(s) and be able to provide 
relevant
+information to image if it is available. If bootloader do not understand 
meaning
+of requested tag(s) it must fail with an error. However, if it support a given
+tag(s) but information conveyed by it/them is not available bootloader can do 
not
+provide requested tag(s) in Multiboot information structure and proceed 
further.
+
+Note: Above means that there is not guarantee that any tags of type 
@samp{mbi_tag_types}
+will actually be present. E.g. on a videoless system even if you requested tag 
@samp{8}
+and bootloader support it no tags of type @samp{8} will be present in Multiboot
+information structure.
 
 
 @node Address header tag
-- 
1.7.10.4


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