Commit graph

64 commits

Author SHA1 Message Date
Andreas Kling
e5afe6a579 UserspaceEmulator: Implement the CMP family of instructions
These are identical to SUB, except they don't store the result (they
only upate the arithmetic flags.)
2020-07-11 13:27:40 +02:00
Andreas Kling
58fd010caf UserspaceEmulator: Implement a bunch of the MOV instructions 2020-07-10 20:29:14 +02:00
Andreas Kling
04d58f54b3 UserspaceEmulator: Implement the SAR instruction
Let's try doing this with some inline assembly. We know we're running
on an x86 target anyway. :^)
2020-07-10 20:20:27 +02:00
Andreas Kling
3899effb19 UserspaceEmulator: Implement the SUB family of instructions 2020-07-10 20:20:27 +02:00
Andreas Kling
0cf7fd5268 UserspaceEmulator+LibX86: Implement all the forms of XOR
And they're all generic, which will make it easy to support more ops.
2020-07-10 20:20:27 +02:00
Andreas Kling
6f27770cea UserspaceEmulator: Add 8/16 bit memory read/write operations 2020-07-10 20:20:27 +02:00
Andreas Kling
f8b38eabeb UserspaceEmulator: First cut of generic instruction implementations
Let's use C++ templates to implement the generic parts of instructions.
There are tons of them with the same set of inputs, just different
behavior. Templates are perfect for this.
2020-07-10 20:20:27 +02:00
Andreas Kling
30ef30ca09 UserspaceEmulator: Add proper segment registers
Some things will flow better if we're able to index into a table of our
segment registers.
2020-07-10 20:20:27 +02:00
Andreas Kling
f1801cfb28 UserspaceEmulator: Fix a Clang warning
Clang didn't like default construction of PartAddressableRegister,
so let's just use memset() then.
2020-07-10 20:20:27 +02:00
Andreas Kling
4d8683b632 UserspaceEmulator: Tidy up SoftCPU's general purpose registers
This patch adds a PartAddressableRegister type, which divides a 32-bit
value into separate parts needed for the EAX/AX/AL/AH register splits.

Clean up the code around register access to make it a little less
cumbersome to use.
2020-07-09 23:27:50 +02:00
Andreas Kling
d10765bec3 UserspaceEmulator: Add an initial stack and implement PUSH/POP reg32
Programs now start out with a 64 KB stack at 0x10000000. :^)
2020-07-09 16:20:08 +02:00
Andreas Kling
8ab601f9e1 UserspaceEmulator: Implement XOR_RM32_reg32
Note that this is a partial implementation since we don't have support
for memory r/m variants yet.
2020-07-07 22:44:58 +02:00
Andreas Kling
934f0b999e UserspaceEmulator: Add arithmetic CPU flags 2020-07-07 22:44:58 +02:00
Andreas Kling
8d8bb07476 UserspaceEmulator: Start building a userspace X86 emulator :^)
This introduces a new X86 CPU emulator for running SerenityOS userspace
programs in a virtualized interpreter environment.

The main goal is to be able to instrument memory accesses and catch
interesting bugs that are very hard to find otherwise. But before we
can do fancy things like that, we have to build a competent emulator
able to actually run programs.

This initial version is able to run a very small program that makes
some tiny syscalls, but nothing more.
2020-07-07 22:44:58 +02:00