first commit
This commit is contained in:
David Ali
22
.gitignore
vendored
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22
.gitignore
vendored
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@@ -0,0 +1,22 @@
|
||||
# --- Build Artifacts ---
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# Directories created by Makefile
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bin/
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obj/
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||||
|
||||
# Object files
|
||||
*.o
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||||
|
||||
# --- Temporary & Editor Files ---
|
||||
# Vim swap files
|
||||
*.swp
|
||||
*.swo
|
||||
|
||||
# VS Code settings
|
||||
.vscode/
|
||||
|
||||
# Linux/General backups
|
||||
*~
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||||
*.bak
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||||
|
||||
# --- System ---
|
||||
.DS_Store
|
||||
21
LICENSE
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21
LICENSE
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@@ -0,0 +1,21 @@
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MIT License
|
||||
|
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Copyright (c) 2026 Dávid Ali
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|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
of this software and associated documentation files (the "Software"), to deal
|
||||
in the Software without restriction, including without limitation the rights
|
||||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
copies of the Software, and to permit persons to whom the Software is
|
||||
furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in all
|
||||
copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
||||
SOFTWARE.
|
||||
20
Makefile
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20
Makefile
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all: bin/nos
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bin:
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mkdir -p bin
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bin/nos: bin obj/nos.o
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ld obj/nos.o -o bin/nos
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obj:
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mkdir -p obj
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obj/nos.o: obj src/nos.asm include/syscalls.inc include/mmap.inc
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nasm -g -f elf64 src/nos.asm -o obj/nos.o -Iinclude
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run: bin/nos
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bin/nos
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@echo "Program returned $$?."
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debug: bin/nos
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gf2 bin/nos
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90
README.md
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90
README.md
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@@ -0,0 +1,90 @@
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# NOS - Experimental Assembly Runtime
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This project is a low-level runtime environment written in x86_64 assembly (NASM) for Linux. It implements a custom memory manager and basic list data structures.
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|
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## Project overview
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|
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The main goal is to understand how computers work at a low level by building a runtime environment from scratch. This project serves as a "bare metal" experiment in manual resource management and data representation.
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||||
|
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Key mechanisms:
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* **Custom Memory Allocation**: It uses the `mmap` system call to reserve 64 MB of RAM.
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* **Cons Structure**: It implements value pairs (cons cells), which are the foundation of languages like Lisp.
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* **Direct Kernel Interface**: The code bypasses the standard C library (`libc`) entirely. It relies on the x86_64 ABI to invoke Linux system calls directly.
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|
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## Project structure
|
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The files are organized as follows:
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* `src/nos.asm`: The main program logic and allocator implementation.
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* `include/syscalls.inc`: Definitions of Linux system call numbers.
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* `include/mmap.inc`: Constants and flags for memory management.
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* `Makefile`: The script for building and testing the project.
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|
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## Requirements
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To run this, you need a 64-bit Linux system and the following tools:
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* `nasm` (Assembler)
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* `ld` (Linker)
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* `make` (Build tool)
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* `gf2` (Optional, for debugging)
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|
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## Usage
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You control the project using the Makefile.
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||||
|
||||
1. **Build**:
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Compiles the executable into the `bin` directory.
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```bash
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make
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||||
```
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|
||||
2. **Run**:
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||||
Compiles (if necessary) and runs the program.
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||||
```bash
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make run
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```
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||||
3. **Debug**:
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Runs the program inside a debugger (default is gf2).
|
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```bash
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make debug
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```
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|
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## How it works
|
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When you run the program, it performs these steps:
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1. **Heap Initialization**: Requests 64 MB of memory using `SYS_MMAP`.
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2. **Allocation**: Creates a `cons` cell with values `0xAAAA` and `0xBBBB`.
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3. **Output**: Prints the following to stdout in hexadecimal:
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* The memory address of the new structure.
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* The first value (head/car).
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* The second value (tail/cdr).
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||||
4. **Exit**: Terminates the process cleanly.
|
||||
|
||||
## Philosophy
|
||||
|
||||
This project adopts a "constructivist" approach to systems programming. We avoid the standard C library (`libc`) not because it is bad, but because it hides the machinery we want to study.
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* **Total transparency**: By avoiding standard libraries, we remove the "black box". Every instruction executed by the CPU is explicit in our source code. There is no hidden initialization code running before `_start`.
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* **Memory control**: General-purpose allocators (like `malloc`) are optimized for average use cases. Building a language runtime requires precise control over the heap layout. We achieve this by managing raw memory pages via `mmap` directly.
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* **The trade-off**: We accept a trade-off: portability for clarity. The code is tightly coupled to the Linux kernel ABI. However, this dependency allows us to interact with the operating system without any abstraction layers blurring the picture.
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## Educational value
|
||||
|
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This project serves as a case study in system software engineering. It explores several core computer science concepts:
|
||||
* **Memory Management**: It demystifies the heap. It shows how to request memory pages directly from the kernel without `malloc`.
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* **Data Structures**: The `cons` function shows how abstract linked lists are physically represented in RAM.
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* **Binary Interface (ABI)**: The code strictly follows System V AMD64 ABI conventions. It requires manual management of registers and the stack.
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||||
* **System Dependency**: It demonstrates how software interacts with the OS kernel boundary without any abstraction layers.
|
||||
|
||||
## TODO - Future plans
|
||||
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||||
The current version is a prototype. Future development will focus on:
|
||||
* [ ] **Garbage Collection (GC)**: The current linear allocator only consumes memory. A mechanism (like Mark and Sweep) is needed to reclaim unused cells.
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||||
* [ ] **Better I/O**: The `print_hex` function is only for debugging. Decimal numbers and string support are needed.
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||||
* [ ] **REPL**: The goal is to build a Read-Eval-Print Loop for interactive commands.
|
||||
* [ ] **Type Tagging**: Currently, everything is a raw 64-bit value. Pointer tagging is needed to distinguish integers from pointers.
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||||
## License
|
||||
|
||||
MIT
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45
include/mmap.inc
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45
include/mmap.inc
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; -----------------------------------------------------------------------------
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||||
; Memory Management Definitions
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||||
; Constants derived from <sys/mman.h> and Linux Kernel documentation.
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; -----------------------------------------------------------------------------
|
||||
|
||||
; Memory Protection Flags
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PROT_NONE equ 0x0 ; Page cannot be accessed
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PROT_READ equ 0x1 ; Page can be read
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PROT_WRITE equ 0x2 ; Page can be written
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PROT_EXEC equ 0x4 ; Page can be executed (Code)
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; --- MMAP Flags (x86-64 Linux) ---
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; Sharing types (Choose one)
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MAP_SHARED equ 0x01 ; Share changes
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MAP_PRIVATE equ 0x02 ; Private copy-on-write
|
||||
MAP_SHARED_VALIDATE equ 0x03 ; Validate flags
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||||
|
||||
; Basic flags
|
||||
MAP_FIXED equ 0x10 ; Interpret addr exactly
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MAP_ANONYMOUS equ 0x20 ; No file backing (RAM only)
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||||
MAP_ANON equ 0x20 ; Alias for MAP_ANONYMOUS
|
||||
MAP_32BIT equ 0x40 ; Allocate in first 2GB (x86-64 only)
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||||
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||||
; Advanced flags
|
||||
MAP_GROWSDOWN equ 0x0100 ; Stack-like segment
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||||
MAP_DENYWRITE equ 0x0800 ; Ignored by modern kernels
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||||
MAP_EXECUTABLE equ 0x1000 ; Ignored by modern kernels
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||||
MAP_LOCKED equ 0x2000 ; Lock pages in memory
|
||||
MAP_NORESERVE equ 0x4000 ; Don't reserve swap space
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||||
MAP_POPULATE equ 0x8000 ; Pre-fault read ahead
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||||
MAP_NONBLOCK equ 0x10000 ; Do not block on IO
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||||
MAP_STACK equ 0x20000 ; Allocation is a stack
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||||
MAP_HUGETLB equ 0x40000 ; Create a huge page
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||||
MAP_SYNC equ 0x80000 ; Perform synchronous page faults
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MAP_FIXED_NOREPLACE equ 0x100000 ; MAP_FIXED but don't clobber
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||||
; Huge Page Sizes (Use with MAP_HUGETLB)
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||||
; Derived from (log2(size) << 26)
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||||
MAP_HUGE_2MB equ 21 << 26 ; 2MB Huge Page
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MAP_HUGE_1GB equ 30 << 26 ; 1GB Huge Page
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||||
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; Legacy / Unused
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MAP_FILE equ 0
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MAP_UNINITIALIZED equ 0 ; Usually not implemented
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364
include/syscalls.inc
Normal file
364
include/syscalls.inc
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; -----------------------------------------------------------------------------
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||||
; Linux x86_64 System Call Table
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; Derived from the Linux Kernel source (arch/x86/entry/syscalls/syscall_64.tbl)
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||||
; -----------------------------------------------------------------------------
|
||||
SYS_READ equ 0
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||||
SYS_WRITE equ 1
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||||
SYS_OPEN equ 2
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||||
SYS_CLOSE equ 3
|
||||
SYS_STAT equ 4
|
||||
SYS_FSTAT equ 5
|
||||
SYS_LSTAT equ 6
|
||||
SYS_POLL equ 7
|
||||
SYS_LSEEK equ 8
|
||||
SYS_MMAP equ 9
|
||||
SYS_MPROTECT equ 10
|
||||
SYS_MUNMAP equ 11
|
||||
SYS_BRK equ 12
|
||||
SYS_RT_SIGACTION equ 13
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||||
SYS_RT_SIGPROCMASK equ 14
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||||
SYS_RT_SIGRETURN equ 15
|
||||
SYS_IOCTL equ 16
|
||||
SYS_PREAD64 equ 17
|
||||
SYS_PWRITE64 equ 18
|
||||
SYS_READV equ 19
|
||||
SYS_WRITEV equ 20
|
||||
SYS_ACCESS equ 21
|
||||
SYS_PIPE equ 22
|
||||
SYS_SELECT equ 23
|
||||
SYS_SCHED_YIELD equ 24
|
||||
SYS_MREMAP equ 25
|
||||
SYS_MSYNC equ 26
|
||||
SYS_MINCORE equ 27
|
||||
SYS_MADVISE equ 28
|
||||
SYS_SHMGET equ 29
|
||||
SYS_SHMAT equ 30
|
||||
SYS_SHMCTL equ 31
|
||||
SYS_DUP equ 32
|
||||
SYS_DUP2 equ 33
|
||||
SYS_PAUSE equ 34
|
||||
SYS_NANOSLEEP equ 35
|
||||
SYS_GETITIMER equ 36
|
||||
SYS_ALARM equ 37
|
||||
SYS_SETITIMER equ 38
|
||||
SYS_GETPID equ 39
|
||||
SYS_SENDFILE equ 40
|
||||
SYS_SOCKET equ 41
|
||||
SYS_CONNECT equ 42
|
||||
SYS_ACCEPT equ 43
|
||||
SYS_SENDTO equ 44
|
||||
SYS_RECVFROM equ 45
|
||||
SYS_SENDMSG equ 46
|
||||
SYS_RECVMSG equ 47
|
||||
SYS_SHUTDOWN equ 48
|
||||
SYS_BIND equ 49
|
||||
SYS_LISTEN equ 50
|
||||
SYS_GETSOCKNAME equ 51
|
||||
SYS_GETPEERNAME equ 52
|
||||
SYS_SOCKETPAIR equ 53
|
||||
SYS_SETSOCKOPT equ 54
|
||||
SYS_GETSOCKOPT equ 55
|
||||
SYS_CLONE equ 56
|
||||
SYS_FORK equ 57
|
||||
SYS_VFORK equ 58
|
||||
SYS_EXECVE equ 59
|
||||
SYS_EXIT equ 60
|
||||
SYS_WAIT4 equ 61
|
||||
SYS_KILL equ 62
|
||||
SYS_UNAME equ 63
|
||||
SYS_SEMGET equ 64
|
||||
SYS_SEMOP equ 65
|
||||
SYS_SEMCTL equ 66
|
||||
SYS_SHMDT equ 67
|
||||
SYS_MSGGET equ 68
|
||||
SYS_MSGSND equ 69
|
||||
SYS_MSGRCV equ 70
|
||||
SYS_MSGCTL equ 71
|
||||
SYS_FCNTL equ 72
|
||||
SYS_FLOCK equ 73
|
||||
SYS_FSYNC equ 74
|
||||
SYS_FDATASYNC equ 75
|
||||
SYS_TRUNCATE equ 76
|
||||
SYS_FTRUNCATE equ 77
|
||||
SYS_GETDENTS equ 78
|
||||
SYS_GETCWD equ 79
|
||||
SYS_CHDIR equ 80
|
||||
SYS_FCHDIR equ 81
|
||||
SYS_RENAME equ 82
|
||||
SYS_MKDIR equ 83
|
||||
SYS_RMDIR equ 84
|
||||
SYS_CREAT equ 85
|
||||
SYS_LINK equ 86
|
||||
SYS_UNLINK equ 87
|
||||
SYS_SYMLINK equ 88
|
||||
SYS_READLINK equ 89
|
||||
SYS_CHMOD equ 90
|
||||
SYS_FCHMOD equ 91
|
||||
SYS_CHOWN equ 92
|
||||
SYS_FCHOWN equ 93
|
||||
SYS_LCHOWN equ 94
|
||||
SYS_UMASK equ 95
|
||||
SYS_GETTIMEOFDAY equ 96
|
||||
SYS_GETRLIMIT equ 97
|
||||
SYS_GETRUSAGE equ 98
|
||||
SYS_SYSINFO equ 99
|
||||
SYS_TIMES equ 100
|
||||
SYS_PTRACE equ 101
|
||||
SYS_GETUID equ 102
|
||||
SYS_SYSLOG equ 103
|
||||
SYS_GETGID equ 104
|
||||
SYS_SETUID equ 105
|
||||
SYS_SETGID equ 106
|
||||
SYS_GETEUID equ 107
|
||||
SYS_GETEGID equ 108
|
||||
SYS_SETPGID equ 109
|
||||
SYS_GETPPID equ 110
|
||||
SYS_GETPGRP equ 111
|
||||
SYS_SETSID equ 112
|
||||
SYS_SETREUID equ 113
|
||||
SYS_SETREGID equ 114
|
||||
SYS_GETGROUPS equ 115
|
||||
SYS_SETGROUPS equ 116
|
||||
SYS_SETRESUID equ 117
|
||||
SYS_GETRESUID equ 118
|
||||
SYS_SETRESGID equ 119
|
||||
SYS_GETRESGID equ 120
|
||||
SYS_GETPGID equ 121
|
||||
SYS_SETFSUID equ 122
|
||||
SYS_SETFSGID equ 123
|
||||
SYS_GETSID equ 124
|
||||
SYS_CAPGET equ 125
|
||||
SYS_CAPSET equ 126
|
||||
SYS_RT_SIGPENDING equ 127
|
||||
SYS_RT_SIGTIMEDWAIT equ 128
|
||||
SYS_RT_SIGQUEUEINFO equ 129
|
||||
SYS_RT_SIGSUSPEND equ 130
|
||||
SYS_SIGALTSTACK equ 131
|
||||
SYS_UTIME equ 132
|
||||
SYS_MKNOD equ 133
|
||||
SYS_USELIB equ 134
|
||||
SYS_PERSONALITY equ 135
|
||||
SYS_USTAT equ 136
|
||||
SYS_STATFS equ 137
|
||||
SYS_FSTATFS equ 138
|
||||
SYS_SYSFS equ 139
|
||||
SYS_GETPRIORITY equ 140
|
||||
SYS_SETPRIORITY equ 141
|
||||
SYS_SCHED_SETPARAM equ 142
|
||||
SYS_SCHED_GETPARAM equ 143
|
||||
SYS_SCHED_SETSCHEDULER equ 144
|
||||
SYS_SCHED_GETSCHEDULER equ 145
|
||||
SYS_SCHED_GET_PRIORITY_MAX equ 146
|
||||
SYS_SCHED_GET_PRIORITY_MIN equ 147
|
||||
SYS_SCHED_RR_GET_INTERVAL equ 148
|
||||
SYS_MLOCK equ 149
|
||||
SYS_MUNLOCK equ 150
|
||||
SYS_MLOCKALL equ 151
|
||||
SYS_MUNLOCKALL equ 152
|
||||
SYS_VHANGUP equ 153
|
||||
SYS_MODIFY_LDT equ 154
|
||||
SYS_PIVOT_ROOT equ 155
|
||||
SYS__SYSCTL equ 156
|
||||
SYS_PRCTL equ 157
|
||||
SYS_ARCH_PRCTL equ 158
|
||||
SYS_ADJTIMEX equ 159
|
||||
SYS_SETRLIMIT equ 160
|
||||
SYS_CHROOT equ 161
|
||||
SYS_SYNC equ 162
|
||||
SYS_ACCT equ 163
|
||||
SYS_SETTIMEOFDAY equ 164
|
||||
SYS_MOUNT equ 165
|
||||
SYS_UMOUNT2 equ 166
|
||||
SYS_SWAPON equ 167
|
||||
SYS_SWAPOFF equ 168
|
||||
SYS_REBOOT equ 169
|
||||
SYS_SETHOSTNAME equ 170
|
||||
SYS_SETDOMAINNAME equ 171
|
||||
SYS_IOPL equ 172
|
||||
SYS_IOPERM equ 173
|
||||
SYS_CREATE_MODULE equ 174
|
||||
SYS_INIT_MODULE equ 175
|
||||
SYS_DELETE_MODULE equ 176
|
||||
SYS_GET_KERNEL_SYMS equ 177
|
||||
SYS_QUERY_MODULE equ 178
|
||||
SYS_QUOTACTL equ 179
|
||||
SYS_NFSSERVCTL equ 180
|
||||
SYS_GETPMSG equ 181
|
||||
SYS_PUTPMSG equ 182
|
||||
SYS_AFS_SYSCALL equ 183
|
||||
SYS_TUXCALL equ 184
|
||||
SYS_SECURITY equ 185
|
||||
SYS_GETTID equ 186
|
||||
SYS_READAHEAD equ 187
|
||||
SYS_SETXATTR equ 188
|
||||
SYS_LSETXATTR equ 189
|
||||
SYS_FSETXATTR equ 190
|
||||
SYS_GETXATTR equ 191
|
||||
SYS_LGETXATTR equ 192
|
||||
SYS_FGETXATTR equ 193
|
||||
SYS_LISTXATTR equ 194
|
||||
SYS_LLISTXATTR equ 195
|
||||
SYS_FLISTXATTR equ 196
|
||||
SYS_REMOVEXATTR equ 197
|
||||
SYS_LREMOVEXATTR equ 198
|
||||
SYS_FREMOVEXATTR equ 199
|
||||
SYS_TKILL equ 200
|
||||
SYS_TIME equ 201
|
||||
SYS_FUTEX equ 202
|
||||
SYS_SCHED_SETAFFINITY equ 203
|
||||
SYS_SCHED_GETAFFINITY equ 204
|
||||
SYS_SET_THREAD_AREA equ 205
|
||||
SYS_IO_SETUP equ 206
|
||||
SYS_IO_DESTROY equ 207
|
||||
SYS_IO_GETEVENTS equ 208
|
||||
SYS_IO_SUBMIT equ 209
|
||||
SYS_IO_CANCEL equ 210
|
||||
SYS_GET_THREAD_AREA equ 211
|
||||
SYS_LOOKUP_DCOOKIE equ 212
|
||||
SYS_EPOLL_CREATE equ 213
|
||||
SYS_EPOLL_CTL_OLD equ 214
|
||||
SYS_EPOLL_WAIT_OLD equ 215
|
||||
SYS_REMAP_FILE_PAGES equ 216
|
||||
SYS_GETDENTS64 equ 217
|
||||
SYS_SET_TID_ADDRESS equ 218
|
||||
SYS_RESTART_SYSCALL equ 219
|
||||
SYS_SEMTIMEDOP equ 220
|
||||
SYS_FADVISE64 equ 221
|
||||
SYS_TIMER_CREATE equ 222
|
||||
SYS_TIMER_SETTIME equ 223
|
||||
SYS_TIMER_GETTIME equ 224
|
||||
SYS_TIMER_GETOVERRUN equ 225
|
||||
SYS_TIMER_DELETE equ 226
|
||||
SYS_CLOCK_SETTIME equ 227
|
||||
SYS_CLOCK_GETTIME equ 228
|
||||
SYS_CLOCK_GETRES equ 229
|
||||
SYS_CLOCK_NANOSLEEP equ 230
|
||||
SYS_EXIT_GROUP equ 231
|
||||
SYS_EPOLL_WAIT equ 232
|
||||
SYS_EPOLL_CTL equ 233
|
||||
SYS_TGKILL equ 234
|
||||
SYS_UTIMES equ 235
|
||||
SYS_VSERVER equ 236
|
||||
SYS_MBIND equ 237
|
||||
SYS_SET_MEMPOLICY equ 238
|
||||
SYS_GET_MEMPOLICY equ 239
|
||||
SYS_MQ_OPEN equ 240
|
||||
SYS_MQ_UNLINK equ 241
|
||||
SYS_MQ_TIMEDSEND equ 242
|
||||
SYS_MQ_TIMEDRECEIVE equ 243
|
||||
SYS_MQ_NOTIFY equ 244
|
||||
SYS_MQ_GETSETATTR equ 245
|
||||
SYS_KEXEC_LOAD equ 246
|
||||
SYS_WAITID equ 247
|
||||
SYS_ADD_KEY equ 248
|
||||
SYS_REQUEST_KEY equ 249
|
||||
SYS_KEYCTL equ 250
|
||||
SYS_IOPRIO_SET equ 251
|
||||
SYS_IOPRIO_GET equ 252
|
||||
SYS_INOTIFY_INIT equ 253
|
||||
SYS_INOTIFY_ADD_WATCH equ 254
|
||||
SYS_INOTIFY_RM_WATCH equ 255
|
||||
SYS_MIGRATE_PAGES equ 256
|
||||
SYS_OPENAT equ 257
|
||||
SYS_MKDIRAT equ 258
|
||||
SYS_MKNODAT equ 259
|
||||
SYS_FCHOWNAT equ 260
|
||||
SYS_FUTIMESAT equ 261
|
||||
SYS_NEWFSTATAT equ 262
|
||||
SYS_UNLINKAT equ 263
|
||||
SYS_RENAMEAT equ 264
|
||||
SYS_LINKAT equ 265
|
||||
SYS_SYMLINKAT equ 266
|
||||
SYS_READLINKAT equ 267
|
||||
SYS_FCHMODAT equ 268
|
||||
SYS_FACCESSAT equ 269
|
||||
SYS_PSELECT6 equ 270
|
||||
SYS_PPOLL equ 271
|
||||
SYS_UNSHARE equ 272
|
||||
SYS_SET_ROBUST_LIST equ 273
|
||||
SYS_GET_ROBUST_LIST equ 274
|
||||
SYS_SPLICE equ 275
|
||||
SYS_TEE equ 276
|
||||
SYS_SYNC_FILE_RANGE equ 277
|
||||
SYS_VMSPLICE equ 278
|
||||
SYS_MOVE_PAGES equ 279
|
||||
SYS_UTIMENSAT equ 280
|
||||
SYS_EPOLL_PWAIT equ 281
|
||||
SYS_SIGNALFD equ 282
|
||||
SYS_TIMERFD_CREATE equ 283
|
||||
SYS_EVENTFD equ 284
|
||||
SYS_FALLOCATE equ 285
|
||||
SYS_TIMERFD_SETTIME equ 286
|
||||
SYS_TIMERFD_GETTIME equ 287
|
||||
SYS_ACCEPT4 equ 288
|
||||
SYS_SIGNALFD4 equ 289
|
||||
SYS_EVENTFD2 equ 290
|
||||
SYS_EPOLL_CREATE1 equ 291
|
||||
SYS_DUP3 equ 292
|
||||
SYS_PIPE2 equ 293
|
||||
SYS_INOTIFY_INIT1 equ 294
|
||||
SYS_PREADV equ 295
|
||||
SYS_PWRITEV equ 296
|
||||
SYS_RT_TGSIGQUEUEINFO equ 297
|
||||
SYS_PERF_EVENT_OPEN equ 298
|
||||
SYS_RECVMMSG equ 299
|
||||
SYS_FANOTIFY_INIT equ 300
|
||||
SYS_FANOTIFY_MARK equ 301
|
||||
SYS_PRLIMIT64 equ 302
|
||||
SYS_NAME_TO_HANDLE_AT equ 303
|
||||
SYS_OPEN_BY_HANDLE_AT equ 304
|
||||
SYS_CLOCK_ADJTIME equ 305
|
||||
SYS_SYNCFS equ 306
|
||||
SYS_SENDMMSG equ 307
|
||||
SYS_SETNS equ 308
|
||||
SYS_GETCPU equ 309
|
||||
SYS_PROCESS_VM_READV equ 310
|
||||
SYS_PROCESS_VM_WRITEV equ 311
|
||||
SYS_KCMP equ 312
|
||||
SYS_FINIT_MODULE equ 313
|
||||
SYS_SCHED_SETATTR equ 314
|
||||
SYS_SCHED_GETATTR equ 315
|
||||
SYS_RENAMEAT2 equ 316
|
||||
SYS_SECCOMP equ 317
|
||||
SYS_GETRANDOM equ 318
|
||||
SYS_MEMFD_CREATE equ 319
|
||||
SYS_KEXEC_FILE_LOAD equ 320
|
||||
SYS_BPF equ 321
|
||||
SYS_EXECVEAT equ 322
|
||||
SYS_USERFAULTFD equ 323
|
||||
SYS_MEMBARRIER equ 324
|
||||
SYS_MLOCK2 equ 325
|
||||
SYS_COPY_FILE_RANGE equ 326
|
||||
SYS_PREADV2 equ 327
|
||||
SYS_PWRITEV2 equ 328
|
||||
SYS_PKEY_MPROTECT equ 329
|
||||
SYS_PKEY_ALLOC equ 330
|
||||
SYS_PKEY_FREE equ 331
|
||||
SYS_STATX equ 332
|
||||
|
||||
STDIN equ 0
|
||||
STDOUT equ 1
|
||||
STDERR equ 2
|
||||
|
||||
%macro m_syscall 1-7
|
||||
mov rax, %1
|
||||
%if %0 > 1
|
||||
mov rdi, %2
|
||||
%endif
|
||||
%if %0 > 2
|
||||
mov rsi, %3
|
||||
%endif
|
||||
%if %0 > 3
|
||||
mov rdx, %4
|
||||
%endif
|
||||
%if %0 > 4
|
||||
mov r10, %5
|
||||
%endif
|
||||
%if %0 > 5
|
||||
mov r8, %6
|
||||
%endif
|
||||
%if %0 > 6
|
||||
mov r9, %7
|
||||
%endif
|
||||
syscall
|
||||
%endmacro
|
||||
84
src/nos.asm
Normal file
84
src/nos.asm
Normal file
@@ -0,0 +1,84 @@
|
||||
%include "syscalls.inc"
|
||||
%include "mmap.inc"
|
||||
|
||||
HEAP_SIZE equ 64 * 1024 * 1024 ; 64 Megabytes
|
||||
|
||||
section .bss
|
||||
heap_start: resq 1
|
||||
heap_cursor: resq 1
|
||||
heap_end: resq 1
|
||||
|
||||
section .text
|
||||
global _start
|
||||
|
||||
_start:
|
||||
call heap_init
|
||||
mov rdi, 0xAAAA
|
||||
mov rsi, 0xBBBB
|
||||
call cons
|
||||
mov rbx, rax
|
||||
mov rdi, rbx
|
||||
call print_hex
|
||||
mov rdi, [rbx]
|
||||
call print_hex
|
||||
mov rdi, [rbx+8]
|
||||
call print_hex
|
||||
m_syscall SYS_EXIT, 0
|
||||
|
||||
heap_init:
|
||||
m_syscall SYS_MMAP, 0, HEAP_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0
|
||||
cmp rax, 0
|
||||
jl .error
|
||||
mov [heap_start], rax
|
||||
mov [heap_cursor], rax
|
||||
add rax, HEAP_SIZE
|
||||
mov [heap_end], rax
|
||||
ret
|
||||
.error:
|
||||
m_syscall SYS_WRITE, STDOUT, msg_err, msg_err_len
|
||||
m_syscall SYS_EXIT, 1
|
||||
|
||||
cons:
|
||||
mov rax, [heap_cursor]
|
||||
mov rdx, rax
|
||||
add rdx, 16
|
||||
cmp rdx, [heap_end]
|
||||
ja .heap_overflow
|
||||
mov [rax], rdi
|
||||
mov [rax+8], rsi
|
||||
mov [heap_cursor], rdx
|
||||
ret
|
||||
.heap_overflow:
|
||||
m_syscall SYS_WRITE, STDOUT, msg_oom, msg_oom_len
|
||||
m_syscall SYS_EXIT, 1
|
||||
|
||||
print_hex:
|
||||
sub rsp, 24
|
||||
mov rcx, 16
|
||||
mov rsi, rsp
|
||||
add rsi, 15
|
||||
mov rax, rdi
|
||||
.loop:
|
||||
mov rdx, rax
|
||||
and rdx, 0xF
|
||||
cmp dl, 9
|
||||
jbe .digit
|
||||
add dl, 7
|
||||
.digit:
|
||||
add dl, '0'
|
||||
mov [rsi], dl
|
||||
dec rsi
|
||||
shr rax, 4
|
||||
loop .loop
|
||||
mov byte [rsp+16], 10
|
||||
m_syscall SYS_WRITE, STDOUT, rsp, 17
|
||||
add rsp, 24
|
||||
ret
|
||||
|
||||
section .data
|
||||
msg_ok: db "Heap initialized successfully.", 10
|
||||
msg_ok_len: equ $ - msg_ok
|
||||
msg_err: db "CRITICAL: Failed to allocate heap memory.", 10
|
||||
msg_err_len: equ $ - msg_err
|
||||
msg_oom: db "CRITICAL: Out of memory (Heap full).", 10
|
||||
msg_oom_len: equ $ - msg_oom
|
||||
Reference in New Issue
Block a user