Commit graph

661 commits

Author SHA1 Message Date
Andreas Kling
5ecbfd8451 UserspaceEmulator: Add the STC/CLC and STD/CLD instructions 2020-07-13 13:50:22 +02:00
Andreas Kling
9f293054e8 UserspaceEmulator: Implement the ADC instruction 2020-07-13 13:50:22 +02:00
Andreas Kling
6230c60296 UserspaceEmulator: Make SBB actually respect the SoftCPU carry flag
We were forgetting to set the host CPU's carry flag before executing
the SBB instruction. This made the result a bit unpredictable. :^)
2020-07-13 13:50:22 +02:00
Andreas Kling
a9f92e5d75 UserspaceEmulator: Remove an unnecessary step in some instructions
We don't need to move the result of shifts around like this, we can
just use inline assembly outputs to make it end up in the right place.
2020-07-13 13:50:22 +02:00
Andreas Kling
80d3306840 UserspaceEmulator: Fix wrong ESI/EDI step sizes in MOVSW and MOVSD 2020-07-13 13:50:22 +02:00
Andreas Kling
e0580e2975 UserspaceEmulator: Add some more syscalls
We can now unmap mapped memory, among other things. This is all very
ad-hoc as I'm trying to run UserspaceEmulator inside itself. :^)
2020-07-13 13:50:22 +02:00
Andreas Kling
9b6464010f UserspaceEmulator: Add basic support for memory-mapped files
MmapRegion now supports using an mmap'ed file descriptor as backing.
2020-07-13 13:50:22 +02:00
Andreas Kling
63d3f5d19b UserspaceEmulator: Implement the PUSHFD instruction 2020-07-13 13:50:22 +02:00
Andreas Kling
f6ad5edab0 UserspaceEmulator: Make mmap'ed memory track read/write protection
Here's the first time we get a taste of better information than the
real hardware can give us: unlike x86 CPUs, we can actually support
write-only memory, so now we do!

While this isn't immediately useful, it's still pretty cool. :^)
2020-07-13 13:50:22 +02:00
Andreas Kling
27c1690504 UserspaceEmulator: Pass arguments through to emulated process
Ultimately we'll want to support passing some options to the emulator
as well, but for now just pass all arguments (except argv[0] of course)
through to the emulated process.

This is still not perfect, but slightly better than what we had before.
2020-07-13 13:50:22 +02:00
Andreas Kling
3d42b85969 UserspaceEmulator: Move SimpleRegion to its own files 2020-07-13 13:50:22 +02:00
Andreas Kling
4d3787ae33 UserspaceEmulator: Support the fstat() and get_process_name() syscalls
For now, we just pretend that the process name is "EMULATED". We can
probably do better though. :^)
2020-07-13 13:50:22 +02:00
Andreas Kling
617655db0d UserspaceEmulator: Move exit() syscall logging to debug output
We want the emulated program to appear without noise in the terminal.
2020-07-12 21:37:54 +02:00
Andreas Kling
1d32c66dde UserspaceEmulator: Put some syscall logging behind DEBUG_SPAM 2020-07-12 21:37:54 +02:00
Andreas Kling
95a42efc62 UserspaceEmulator: Implement enough syscalls to get /bin/id running :^) 2020-07-12 21:37:54 +02:00
Andreas Kling
1b196df4c4 UserspaceEmulator: Implement/stub out various syscalls
Moving forward on getting /bin/id to run inside the emulator. :^)
2020-07-12 21:37:54 +02:00
Andreas Kling
56d3a949e6 UserspaceEmulator: Disable per-instruction trace dumps for now
With tracing turned on, it's just too slow when doing big operations
like initializing malloc freelists.
2020-07-12 21:37:54 +02:00
Andreas Kling
079021a607 UserspaceEmulator: Put the executable name in argv[0] :^)
The emulated program can now find its own name in argv[0]. Very cool!
2020-07-12 21:37:54 +02:00
Andreas Kling
ddf7b817df UserspaceEmulator: Add Emulator::dump_backtrace()
This gives you a nice, symbolicated backtrace at the current EIP. :^)
2020-07-12 21:37:54 +02:00
Andreas Kling
584923445c UserspaceEmulator: "Add" a couple of syscalls
This patch adds gettid() and stubs out pledge() and unveil() for now.
2020-07-12 21:37:54 +02:00
Andreas Kling
e461e3c8b0 UserspaceEmulator: Fix missing sign extension in PUSH_imm8 2020-07-12 17:44:14 +02:00
Andreas Kling
94f07660e9 UserspaceEmulator: Add some convenient SoftMMU APIs for copying data
We'll soon want to copy data in and out of the SoftMMU memory space.
2020-07-12 17:42:57 +02:00
Andreas Kling
274ac3c628 UserspaceEmulator: Implement the XADD instruction 2020-07-12 15:35:01 +02:00
Andreas Kling
04695957e2 UserspaceEmulator: Implement the MOVSX instruction 2020-07-12 15:33:29 +02:00
Andreas Kling
8940916232 UserspaceEmulator: Implement JMP_RM32 2020-07-12 14:54:30 +02:00
Andreas Kling
a424208399 UserspaceEmulator: Implement DIV_RM32
Not using inline assembly for this one since flags are undefined after
a DIV instruction anyway.
2020-07-12 14:53:19 +02:00
Andreas Kling
062e2f8614 UserspaceEmulator: Implement the XCHG instruction 2020-07-12 14:45:46 +02:00
Andreas Kling
536ca0f8c9 UserspaceEmulator: Implement some more MOV variants 2020-07-12 14:45:35 +02:00
Andreas Kling
2d44f4526a UserspaceEmulator: Implement MOVSB/MOVSW/MOVSD 2020-07-12 14:45:02 +02:00
Andreas Kling
ed57efff4f UserspaceEmulator: Implement the CMPXCHG instruction 2020-07-12 14:43:30 +02:00
Andreas Kling
6ec0a63af1 UserspaceEmulator: Fix broken MOV_RM8_reg8 2020-07-12 14:42:15 +02:00
Andreas Kling
bdf72a7c7a UserspaceEmulator: Implement JMP_NEAR_imm
This is a full-width relative jump, when the 8-bit immediate variant
isn't large enough.
2020-07-12 01:36:45 +02:00
Andreas Kling
938a00ecf9 UserspaceEmulator: Implement the CMOVcc instruction 2020-07-12 01:36:45 +02:00
Andreas Kling
adf3775955 UserspaceEmulator: Implement the SBB family of instructions 2020-07-12 01:36:45 +02:00
Andreas Kling
734f63d522 UserspaceEmulator: Add basic TLS (thread-local storage) support
The SoftMMU now receives full X86::LogicalAddress values from SoftCPU.
This allows the MMU to reroute TLS accesses to a special memory region.

The ELF executable's PT_TLS header tells us how to allocate the TLS.

Basically, the GS register points to a magical 4-byte area which has
a pointer to the TCB (thread control block). The TCB lives in normal
flat memory space and is accessed through the DS register.
2020-07-12 01:36:45 +02:00
Andreas Kling
df95e25eaa UserspaceEmulator: Implement the NEG instruction
Per the Intel manuals, NEG is equivalent to subtracting a value from 0.
2020-07-12 01:36:45 +02:00
Andreas Kling
aa13183615 UserspaceEmulator: Implement SETcc_RM8 2020-07-12 01:36:45 +02:00
Andreas Kling
b524bc123d UserspaceEmulator: Implement the DEC family of instructions 2020-07-12 01:36:45 +02:00
Andreas Kling
ce51cf90c6 UserspaceEmulator: Make sure ELF data segments are zero-initialized
(And all other memory, too.) This will mutate later when we add shadow
memory etc, but for now just zero-initialize it since that's expected
by the emulated program.
2020-07-12 01:36:45 +02:00
Andreas Kling
8a94622e54 UserspaceEmulator: Put memory read/write logging behind MEMORY_DEBUG 2020-07-11 23:57:14 +02:00
Andreas Kling
775bc158ba UserspaceEmulator: Implement the SHL family of instructions 2020-07-11 23:57:14 +02:00
Andreas Kling
bfacb9583a UserspaceEmulator: Implement RET_imm16
This is just like RET, but it also pops N bytes off the stack.
2020-07-11 23:57:14 +02:00
Andreas Kling
eb86264d3b UserspaceEmulator: Simplify op_foo templates
Instead of templatizing both the destination and source types, simply
templatize the operand type and sign-extend narrower source values at
the call sites instead.
2020-07-11 23:57:14 +02:00
Andreas Kling
6febad1ef3 UserspaceEmulator: The generic_RM*_imm8 functions need to sign extend
We are supposed to sign-extend the 8-bit immediate here,
"cmp eax, 0xff" is actually "cmp eax, 0xffffffff"
2020-07-11 23:57:14 +02:00
Andreas Kling
21837544bb UserspaceEmulator: Implement MOV_EAX_moff32 2020-07-11 23:57:14 +02:00
Andreas Kling
1579cbdc9d UserspaceEmulator: Implement CALL_RM32 2020-07-11 23:57:14 +02:00
Andreas Kling
a6719ede0b UserspaceEmulator: Implement the SHR family of instructions 2020-07-11 23:57:14 +02:00
Andreas Kling
2ee451afed UserspaceEmulator: Implement SHR_RM32_imm8 2020-07-11 23:57:14 +02:00
Andreas Kling
d79f15e219 UserspaceEmulator: Implement the OR family of instructions 2020-07-11 23:57:14 +02:00
Andreas Kling
cb2e36dde7 UserspaceEmulator: Implement PUSH_imm8
Curiously, the 8-bit immediate is sign-extended.
2020-07-11 23:57:14 +02:00