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* 7842 - new directory organizationKartik K. Agaram2021-03-031-0/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Baremetal is now the default build target and therefore has its sources at the top-level. Baremetal programs build using the phase-2 Mu toolchain that requires a Linux kernel. This phase-2 codebase which used to be at the top-level is now under the linux/ directory. Finally, the phase-2 toolchain, while self-hosting, has a way to bootstrap from a C implementation, which is now stored in linux/bootstrap. The bootstrap C implementation uses some literate programming tools that are now in linux/bootstrap/tools. So the whole thing has gotten inverted. Each directory should build one artifact and include the main sources (along with standard library). Tools used for building it are relegated to sub-directories, even though those tools are often useful in their own right, and have had lots of interesting programs written using them. A couple of things have gotten dropped in this process: - I had old ways to run on just a Linux kernel, or with a Soso kernel. No more. - I had some old tooling for running a single test at the cursor. I haven't used that lately. Maybe I'll bring it back one day. The reorg isn't done yet. Still to do: - redo documentation everywhere. All the README files, all other markdown, particularly vocabulary.md. - clean up how-to-run comments at the start of programs everywhere - rethink what to do with the html/ directory. Do we even want to keep supporting it? In spite of these shortcomings, all the scripts at the top-level, linux/ and linux/bootstrap are working. The names of the scripts also feel reasonable. This is a good milestone to take stock at.
* 6090 - new instruction: multiply by immediateKartik Agaram2020-03-061-0/+0
This is a 3-operand instruction: r32 = rm32 * imm32 It looks like https://c9x.me/x86/html/file_module_x86_id_138.html has a bug, implying the same opcode supports a 2-operand version. I don't see that in the Intel manual pdf, or at alternative sites like https://www.felixcloutier.com/x86/imul Native runs seem to validate my understanding. In the process I also fixed a bug in the existing multiply instruction 0f af: the only flags it sets are OF and CF. The other existing multiply instruction f7 was doing things right.