| iOS (XNU) Kernel Function |
Android (Linux) Kernel Function |
Description |
| task_for_pid |
find_task_by_vpid |
Find a task_struct by its process ID |
| vfs_getattr |
vfs_stat |
Get file attributes (stat) |
| vfs_read |
vfs_read_file |
Read data from a file |
| vfs_write |
vfs_write_file |
Write data to a file |
| kern_return_t |
int or void |
Return type for various kernel functions |
| mach_msg |
ipc_send or ipc_receive |
Inter-process communication using messages |
| thread_create |
kthread_create |
Create a new thread |
| vm_map |
mm_struct |
Data structure representing a virtual memory map |
| kern_execve |
do_execve |
Execute a new program |
| kern_fork |
do_fork |
Create a new process (fork) |
| kern_exit |
do_exit |
Terminate a process (exit) |
| kern_wait4 |
do_wait |
Wait for a child process to exit |
| thread_terminate |
do_exit |
Terminate a thread |
| thread_suspend |
send_sig |
Suspend a thread |
| thread_resume |
send_sig |
Resume a suspended thread |
| vm_allocate |
vm_mmap |
Allocate virtual memory |
| vm_deallocate |
vm_munmap |
Deallocate virtual memory |
| mach_vm_protect |
mprotect |
Change memory protection |
| task_suspend |
send_sig |
Suspend a task (process) |
| task_resume |
send_sig |
Resume a suspended task (process) |
| vfs_lookup |
d_find_alias or lookup_dentry |
Lookup a file or directory in the filesystem |
| iOS (XNU) Kernel Struct |
Android (Linux) Kernel Struct |
Description |
task_struct |
task_struct |
Represents a process or task |
thread |
task_struct |
Represents a thread within a process |
vm_map |
mm_struct |
Represents a virtual memory map |
vm_object |
vm_area_struct |
Represents a virtual memory object |
vm_page |
page |
Represents a page of virtual memory |
file |
file |
Represents an open file descriptor |
dentry |
dentry |
Represents a directory entry in the filesystem |
inode |
inode |
Represents an inode in the filesystem |
file_operations |
file_operations |
Defines file operation functions |
super_block |
super_block |
Represents a filesystem superblock |
address_space |
address_space |
Manages the address space of a process |
mmu_gather |
mmu_gather |
Used for TLB (Translation Lookaside Buffer) operations |
Certainly, here are the tables in markdown format with some indication of relevant versions or start years where applicable:
Scheduling Policies and Priorities:
| iOS (XNU) Scheduler |
Android (Linux) Scheduler |
Description |
| Priority-Based (Mach) |
Completely Fair Scheduler (CFS) |
Introduced in iOS (XNU) 2.5 (early versions used a different scheduler) |
| Real-Time and Fair Schedulers (Mach) |
Round Robin Scheduler |
Real-time scheduler (Fixed priority) and fair scheduler for background tasks in iOS |
| Priority Ranges (Mach) |
Nice Values |
Priority values typically range from -20 to +20 in Android |
IPC Mechanisms:
| iOS (XNU) IPC Mechanisms |
Android (Linux) IPC Mechanisms |
Description |
| Mach Messages |
Inter-Process Communication (IPC) |
Mach IPC is part of the XNU kernel, while Android uses Binder IPC |
| Port Rights (Mach) |
Binder IPC |
Binder IPC framework introduced in Android 1.0 |
| XPC (XNU) |
Socket IPC |
XPC introduced in iOS 7 (Grand Central Dispatch, GCD) |
File Systems:
| iOS (XNU) File Systems |
Android (Linux) File Systems |
Description |
| HFS+ (Historically) |
Ext4 (Historically) |
Default file systems in older versions |
| APFS (Current) |
F2FS (Some Devices) |
APFS introduced in iOS 10, F2FS used on some Android devices |
| File System APIs |
VFS (Virtual File System) |
Abstraction layers for file operations |
Memory Management:
| iOS (XNU) Memory Management |
Android (Linux) Memory Management |
Description |
| Mach Virtual Memory System |
Page Cache and Slab Allocator |
Mach VM system in iOS (XNU), Page Cache and Slab Allocator in Linux |
| ARC (Automatic Reference Counting) |
Garbage Collection (Java) |
iOS memory management for Objective-C/Swift, Java GC for Android |
Power Management:
| iOS (XNU) Power Management |
Android (Linux) Power Management |
Description |
| Advanced Power Management (APM) |
Advanced Power Management (APM) |
Power-saving strategies and APIs for devices |
| Energy Impact Measurement |
Battery Stats Framework |
Introduced in iOS 9, Battery Stats in Android |
Device Drivers:
| iOS (XNU) Device Drivers |
Android (Linux) Device Drivers |
Description |
| Proprietary and Open-Source Drivers |
Kernel and Vendor-Specific Drivers |
iOS uses proprietary drivers for Apple devices, Android uses a combination of open-source and vendor-specific drivers |
| IOKit Framework (XNU) |
Hardware Abstraction Layer (HAL) |
Abstraction layers for device interaction |
Security Models:
| iOS (XNU) Security Model |
Android (Linux) Security Model |
Description |
| App Sandbox (App Store) |
SELinux (Security-Enhanced Linux) |
App sandboxing enforced in iOS, SELinux introduced in Android 4.3 (Jelly Bean) |
| Code Signing (App Store) |
Android Permissions System |
Code signing required for iOS apps, Permissions system for Android apps |