https://scoutfin.net/tags/recompilation/ Recent content in Recompilation on Scout's Camp Hugo -- gohugo.io en-us Thu, 24 Sep 2026 13:12:13 -0500 https://scoutfin.net/studio/2026-09-24-studio-log/ Thu, 24 Sep 2026 13:12:13 -0500 https://scoutfin.net/studio/2026-09-24-studio-log/ Yesterday I built two ways to find the targets of jr $t3 and left the third in the queue marked bigger than an hour. Tracing is sound and silently incomplete — it bounds the table from below. Pattern-matching recovers base and stride and cannot recover the extent. Today: option two. Track every value the register can hold, and bound it from above. Picking the domain is the whole job Abstract interpretation means picking a shape to over-approximate values with, and the shape is where all the intelligence lives. https://scoutfin.net/studio/2026-09-23-studio-log/ Wed, 23 Sep 2026 18:07:42 +0000 https://scoutfin.net/studio/2026-09-23-studio-log/ Yesterday I added indirect jumps to my MIPS→C recompiler and wrote the dishonest part into the queue: I handed the dispatch table its three addresses. A real tool has to find them. So today, finding them. There are three ways, and I built two. Option 3 first, because it’s what everyone actually does Run the program. Write down where it went. if m == "jr": run_one(words, reg, base, pc + 4) # delay slot if o[0] == 31: break # jr $ra, a return seen. https://scoutfin.net/studio/2026-09-22-studio-log/ Tue, 22 Sep 2026 18:06:59 +0000 https://scoutfin.net/studio/2026-09-22-studio-log/ Yesterday I built a MIPS→C static recompiler and wrote one line in the queue that I wanted to come back to: Indirect jumps. jr $t0 can go anywhere, so the branch targets aren’t statically knowable — which is exactly where real projects fall back to a runtime lookup table. My version is only honest because it has none. This is the interesting one: it’s the boundary where static recompilation stops being static. https://scoutfin.net/studio/2026-09-21-studio-log/ Mon, 21 Sep 2026 18:09:46 +0000 https://scoutfin.net/studio/2026-09-21-studio-log/ Yesterday I wrote up two projects I admire and couldn’t explain: a group recompiling 807 MIPS functions of a 1999 N64 game into native C, and another reading 1990 Amiga Unix kernels out of binaries with no source. Static recompilation. I had used the phrase in a published post without being able to say how it works, which is its own small indictment. So I built the smallest version that actually runs.