RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-10-31 12:12:45 +00:00
Code Issues Activity Actions

UserspaceEmulator: Put the executable name in argv[0] :^)

Browse source 
The emulated program can now find its own name in argv[0]. Very cool!
This commit is contained in:
Andreas Kling 2020-07-12 20:24:10 +02:00
parent ddf7b817df
commit 079021a607
5 changed files with 23 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

13
DevTools/UserspaceEmulator/Emulator.cpp
View file

@ -26,6 +26,7 @@
#include "Emulator.h"
#include "SoftCPU.h"
#include <AK/LexicalPath.h>
#include <AK/LogStream.h>
#include <Kernel/API/Syscall.h>
#include <stdio.h>
@ -92,9 +93,10 @@ private:
u8* m_data { nullptr };
};
Emulator::Emulator(NonnullRefPtr<ELF::Loader> elf)
Emulator::Emulator(const String& executable_path, NonnullRefPtr<ELF::Loader> elf)
: m_elf(move(elf))
, m_cpu(*this)
, m_executable_path(executable_path)
{
setup_stack();
}
@ -105,16 +107,19 @@ void Emulator::setup_stack()
m_mmu.add_region(move(stack_region));
m_cpu.set_esp(stack_location + stack_size);
m_cpu.push_string(LexicalPath(m_executable_path).basename());
u32 argv0 = m_cpu.esp();
m_cpu.push32(0); // char** envp = { nullptr }
u32 envp = m_cpu.esp();
m_cpu.push32(0); // char** argv = { nullptr }
m_cpu.push32(0); // char** argv = { argv0, nullptr }
m_cpu.push32(argv0);
u32 argv = m_cpu.esp();
m_cpu.push32(0); // (alignment)
m_cpu.push32(0); // (alignment)
u32 argc = 0;
u32 argc = 1;
m_cpu.push32(envp);
m_cpu.push32(argv);
m_cpu.push32(argc);

4
DevTools/UserspaceEmulator/Emulator.h
View file

@ -37,7 +37,7 @@ namespace UserspaceEmulator {
class Emulator {
public:
explicit Emulator(NonnullRefPtr<ELF::Loader>);
Emulator(const String& executable_path, NonnullRefPtr<ELF::Loader>);
bool load_elf();
void dump_backtrace();
@ -63,6 +63,8 @@ private:
bool m_shutdown { false };
int m_exit_status { 0 };
String m_executable_path;
};
}

8
DevTools/UserspaceEmulator/SoftCPU.cpp
View file

@ -139,6 +139,14 @@ void SoftCPU::write_memory32(X86::LogicalAddress address, u32 value)
m_emulator.mmu().write32(address, value);
}
void SoftCPU::push_string(const StringView& string)
{
size_t space_to_allocate = round_up_to_power_of_two(string.length() + 1, 16);
set_esp(esp() - space_to_allocate);
m_emulator.mmu().copy_to_vm(esp(), string.characters_without_null_termination(), string.length());
m_emulator.mmu().write8({ 0x20, esp() + string.length() }, '\0');
}
void SoftCPU::push32(u32 value)
{
set_esp(esp() - sizeof(value));

2
DevTools/UserspaceEmulator/SoftCPU.h
View file

@ -75,6 +75,8 @@ public:
void push32(u32);
u32 pop32();
void push_string(const StringView&);
u16 segment(X86::SegmentRegister seg) const { return m_segment[(int)seg]; }
u16& segment(X86::SegmentRegister seg) { return m_segment[(int)seg]; }

2
DevTools/UserspaceEmulator/main.cpp
View file

@ -47,7 +47,7 @@ int main(int argc, char** argv)
auto elf = ELF::Loader::create((const u8*)mapped_file.data(), mapped_file.size());
UserspaceEmulator::Emulator emulator(move(elf));
UserspaceEmulator::Emulator emulator(executable_path, move(elf));
if (!emulator.load_elf())
return 1;