A bootloader image which only seems to have been used on a few ASUS
devices. The encoding is ASCII, because the releasetools.py script
is written using Python 2, where the default encoding is ASCII.
A test file can be found in the firmware files for the "fugu" device, which can be downloaded from https://developers.google.com/android/images
This page hosts a formal specification of ASUS Fugu bootloader.img format (version 2 and later) using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
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subgraph cluster__android_bootldr_asus {
label="AndroidBootldrAsus";
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android_bootldr_asus__seq [label=<<TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0">
<TR><TD BGCOLOR="#E0FFE0">pos</TD><TD BGCOLOR="#E0FFE0">size</TD><TD BGCOLOR="#E0FFE0">type</TD><TD BGCOLOR="#E0FFE0">id</TD></TR>
<TR><TD PORT="magic_pos">0</TD><TD PORT="magic_size">8</TD><TD></TD><TD PORT="magic_type">magic</TD></TR>
<TR><TD PORT="revision_pos">8</TD><TD PORT="revision_size">2</TD><TD>u2le</TD><TD PORT="revision_type">revision</TD></TR>
<TR><TD PORT="reserved1_pos">10</TD><TD PORT="reserved1_size">2</TD><TD>u2le</TD><TD PORT="reserved1_type">reserved1</TD></TR>
<TR><TD PORT="reserved2_pos">12</TD><TD PORT="reserved2_size">4</TD><TD>u4le</TD><TD PORT="reserved2_type">reserved2</TD></TR>
<TR><TD PORT="images_pos">16</TD><TD PORT="images_size">...</TD><TD>Image</TD><TD PORT="images_type">images</TD></TR>
<TR><TD COLSPAN="4" PORT="images__repeat">repeat 3 times</TD></TR>
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subgraph cluster__image {
label="AndroidBootldrAsus::Image";
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image__seq [label=<<TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0">
<TR><TD BGCOLOR="#E0FFE0">pos</TD><TD BGCOLOR="#E0FFE0">size</TD><TD BGCOLOR="#E0FFE0">type</TD><TD BGCOLOR="#E0FFE0">id</TD></TR>
<TR><TD PORT="chunk_id_pos">0</TD><TD PORT="chunk_id_size">8</TD><TD>str(ASCII)</TD><TD PORT="chunk_id_type">chunk_id</TD></TR>
<TR><TD PORT="len_body_pos">8</TD><TD PORT="len_body_size">4</TD><TD>u4le</TD><TD PORT="len_body_type">len_body</TD></TR>
<TR><TD PORT="flags_pos">12</TD><TD PORT="flags_size">1</TD><TD>u1</TD><TD PORT="flags_type">flags</TD></TR>
<TR><TD PORT="reserved1_pos">13</TD><TD PORT="reserved1_size">1</TD><TD>u1</TD><TD PORT="reserved1_type">reserved1</TD></TR>
<TR><TD PORT="reserved2_pos">14</TD><TD PORT="reserved2_size">1</TD><TD>u1</TD><TD PORT="reserved2_type">reserved2</TD></TR>
<TR><TD PORT="reserved3_pos">15</TD><TD PORT="reserved3_size">1</TD><TD>u1</TD><TD PORT="reserved3_type">reserved3</TD></TR>
<TR><TD PORT="body_pos">16</TD><TD PORT="body_size">len_body</TD><TD></TD><TD PORT="body_type">body</TD></TR>
</TABLE>>];
image__inst__file_name [label=<<TABLE BORDER="0" CELLBORDER="1" CELLSPACING="0">
<TR><TD BGCOLOR="#E0FFE0">id</TD><TD BGCOLOR="#E0FFE0">value</TD></TR>
<TR><TD>file_name</TD><TD>(chunk_id == "IFWI!!!!" ? "ifwi.bin" : (chunk_id == "DROIDBT!" ? "droidboot.img" : (chunk_id == "SPLASHS!" ? "splashscreen.img" : "")))</TD></TR>
</TABLE>>];
}
}
android_bootldr_asus__seq:images_type -> image__seq [style=bold];
image__seq:len_body_type -> image__seq:body_size [color="#404040"];
image__seq:chunk_id_type -> image__inst__file_name [color="#404040"];
image__seq:chunk_id_type -> image__inst__file_name [color="#404040"];
image__seq:chunk_id_type -> image__inst__file_name [color="#404040"];
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