Post B7phpYgwrWaAVY8sJE by grawity@social.treehouse.systems
 (DIR) More posts by grawity@social.treehouse.systems
 (DIR) Post #B7nOY9L7a3dHVmzwbg by domi@donotsta.re
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       new video: Polyglot files are AWESOME! we’re exploring what polyglots are, and then dissecting a certain specimen :blobcat3c: watch it here:https://youtu.be/SVAvmZGJ4uchttps://tv.ol-worldwi.de/Polyglot%20files%20are%20Awesome.mp4atom feed for my videos: https://tv.ol-worldwi.de/atom.xml
       
 (DIR) Post #B7phpYgwrWaAVY8sJE by grawity@social.treehouse.systems
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       @la @domi does that mean you can have a polyglot that is both ISO BMFF and ISO 9660?(the latter also reserves 16 sectors × 2048 bytes for "system" use)(which AFAIK originally meant "DEC VAX boot sector")
       
 (DIR) Post #B7phpYz1mJ2nPcbJUO by grawity@social.treehouse.systems
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       @la @domi that reminds me of the mess that is "isohybrid" "dd-able to USB stick" .iso images, which are not only four-way polyglots (MBR, GPT, Mac APM, ISO-9660) but also have different contents depending on what *media* they're written on:- if you write the .iso to a CD (with a logical block size of 2048B), you find an ISO-9660 Volume Descriptor Set at sector 16, and an Apple Partition Map with two entries at sectors 1-2- if you write the .iso to a USB stick, you instead find a GPT partition table at sectors 1 and 12..63, whereas sector 16 is now just an empty GPT slot (because a USB stick's logical block size is now 512B)- the GPT header is deliberately configured to start the actual "table" from sector 12 so that it jumps over the two APM entries (which are now in sectors 4-7 and 8-11 when viewed through a 512B lens)- sector 0, of course contains a MBR with x86 boot code when booting from USB stick (ignored when booting from CD as the first 16 sectors are "reserved system area")