merge multiboot into mbtag-spec

diff --cc ChangeLog
Simple merge

diff --cc doc/boot.S
Simple merge

diff --cc doc/kernel.c
Simple merge

diff --cc doc/multiboot.texi
index 7ba36cdedb987a774aafcd89ed4dee5debe89e3b,631897a15180352f271fefc07cba362922c428ba..efe9b40f67c9314d0f956c3e667d443628d3a22c
--- 1/doc/multiboot.texi
--- 2/doc/multiboot.texi
+++ b/doc/multiboot.texi
@@@ -876,12 -813,14 +876,14 @@@ u32     | reserved          
  @end group
  @end example
  
 -where @samp{size} is the size of the associated structure in bytes, which
 -can be greater than the minimum of 20 bytes. @samp{base_addr} is the
 -starting address. @samp{length} is the size of the memory region in bytes.
 +@samp{size} contains the size of current entry including this field itself. It may be bigger than 24 bytes in future versions but is guaranteed to be
 +@samp{base_addr} is the starting physical address. @samp{length} is the size of the memory region in bytes.
  @samp{type} is the variety of address range represented, where a
- value of 1 indicates available @sc{ram}, and all other values currently
+ value of 1 indicates available @sc{ram}, value of 3 indicates usable memory
+ holding ACPI information, value of 4 indicates reserved memory which needs to
+ be preserved on hibernation and all other values currently
  indicated a reserved area.
 +@samp{reserved} is set to @samp{0} by bootloader and must be ignored by the OS image.
  
  The map provided is guaranteed to list all standard @sc{ram} that should
  be available for normal use.