Add unwind-info.txtunwind

1 files changed, 45 insertions, 0 deletions

diff --git a/unwind-info.txt b/unwind-info.txt
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+Unwind information is defined in two very similar, but subtly
+different formats. One is the eh_frame format, then other is the
+debug_frame format.
+
+Both formats have the concept of CIEs and FDEs. These can be
+dynamically distinguished.
+
+
+.eh_frame
+
+The .eh_frame section is organized as a CIE followed by one or more
+FDEs.
+
+In this format, the CIE pointer/FDE is always 4 bytes, whereas in the
+debug_frame version it is 8 bytes if the initial length indicated a 64
+bit description.
+
+
+		.eh_frame	DWARF 2		DWARF 3
+header:		.eh_frame_hdr	not used	not used
+
+CIE:
+
+Length		32+ext		32 bits		32+ext
+CIE id		32 bits [=0]	32 bits [=-1]	32/64 d.o. ext [=-1]
+version		32 bits [=1]	ubyte [=1]	ubyte [=3]
+augstring	string		string		string
+
+eh data		32/64 do arch	n/a		n/a
+		only if eh in 
+		aug
+
+code alignf	uleb128		uleb128		uleb128
+data alignf	sleb128		sleb128		sleb128	
+return register	?		ubyte		uleb128
+
+aug length	if z in aug,	n/a		n/a
+    		uleb128
+aug data	block
+
+instructions	variable	variable	variable
+padding		nops		nops		nops
+
+
+FDE