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Add x86_64-linux-gnu emulator

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I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.

https://justine.storage.googleapis.com/emulator625.mp4
This commit is contained in:
Justine Tunney 2020-08-25 04:23:25 -07:00
parent 467504308a
commit f4f4caab0e
1052 changed files with 65667 additions and 7825 deletions
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47
ape/ape.S
View file

@ -44,6 +44,7 @@
#include "libc/nexgen32e/uart.h"
#include "libc/nexgen32e/vidya.h"
#include "libc/nt/pedef.h"
#include "libc/nexgen32e/vidya.h"
#include "libc/sysv/consts/prot.h"
.source "NOTICE"
@ -136,43 +137,24 @@ ape.mz: .ascii "MZ" # Mark 'Zibo' Joseph Zbikowski
.short 0 # MZ: OEM information
.org 0x40-4 # MZ: bytes reserved for you
.long RVA(ape.pe) # PE: the new technology
.endobj ape.mz,globl,hidden
.endfn ape.mz,globl,hidden
/ Disk Operating System Stub
/ @noreturn
.org 0x40 # mz/elf header length
stub: mov $0x40,%dl # *literally* dos
jmp 1f # good bios skips here
1: jmp pc
1: jmp pc # thus avoiding heroics
nop # system five bootpoint
.org 0x48,0x90 # ⌂ELF → JNLE 47
jmp 3f
2: push %rdx # don't move or shell script breaks
xor %edx,%edx # Z in MZ ate BIOS drive letter :(
3: .byte 0xbd,0,0 # mov $0x????0000,%[e]bp
jmp pc
jmp ape.hop # already in userspace
.org 0x48,0x90 # note ⌂ELF means JG 47
jmp 3f # MZ also means pop r10
2: sub $8,%rsp # a.k.a. dec %ax sub %sp
xor %edx,%edx # MZ ate BIOS drive code
3: .byte 0xbd,0,0 # a.k.a. mov imm,%bp
jmp pc # real mode, is real
jmp _start # surprise it's unix
.endfn stub
/ Mitigate incidental quotation marks.
.real
ape.hop:pop %rdx
push %r10 # MZ → pop %r10 w/ NexGen32e
.weak __imp_GetStartupInfoW
ezlea __imp_GetStartupInfoW,ax
test %rax,%rax
jz 0f
.weak KernelBase.GetStartupInfo
test %rax,%rax
/ TODO(jart)
/ cmpq $RVA(KernelBase.GetStartupInfo),(%rax)
jz 0f
jmp WinMain
0: .weak _start
jmp _start
.endfn ape.hop
.previous
/*─────────────────────────────────────────────────────────────────────────────╗
│ αcτµαlly pδrταblε εxεcµταblε § ibm personal computer │
╚──────────────────────────────────────────────────────────────────────────────┘
@ -835,9 +817,9 @@ ape.pe: .ascin "PE",4
.short v_ntsubsystem # Subsystem: 0=Neutral,2=GUI,3=Console
.short .LDLLEXE # DllCharacteristics
.quad 0x0000000000100000 # StackReserve
.quad 0x0000000000030000 # StackCommit (64kb [goog] + arg + env)
.quad 0x0000000000100000 # StackCommit
.quad 0x0000000000080000 # HeapReserve
.quad 0x0000000000001000 # HeapCommit (we make our own heap)
.quad 0x0000000000001000 # HeapCommit
.long 0x00000000 # LoaderFlags
.long 16 # NumberOfDirectoryEntries
.long 0,0 # ExportsDirectory
@ -1933,5 +1915,10 @@ __data_start:
.type __piro_start,@object
.hidden __piro_start
.type __ubsan_data_start,@object
.type __ubsan_data_end,@object
.type __ubsan_types_start,@object
.type __ubsan_types_end,@object
.end