How to get updates for macOS Mojave or later
It started out on PowerPC processors but later transitioned onto Intel processors with Mac OS X Leopard (10.5) the last to natively support the PowerPC architecture and Snow Leopard (10.6) the last to support PowerPC applications on Intel-based Macs. All versions of Mac OS X that were made to run on PowerPC systems (with the exception of.
A community of users running Mac OS X on x86 hardware. Global Nav Open Menu Global Nav Close Menu; Apple; Shopping Bag +.
If you've upgraded to macOS Mojave or later, follow these steps to keep it up to date:
- Choose System Preferences from the Apple menu , then click Software Update to check for updates.
- If any updates are available, click the Update Now button to install them. Or click ”More info” to see details about each update and select specific updates to install.
- When Software Update says that your Mac is up to date, the installed version of macOS and all of its apps are also up to date. That includes Safari, iTunes, Books, Messages, Mail, Calendar, Photos, and FaceTime.
To find updates for iMovie, Garageband, Pages, Numbers, Keynote, and other apps that were downloaded separately from the App Store, open the App Store on your Mac, then click the Updates tab.
To automatically install macOS updates in the future, including apps that were downloaded separately from the App Store, select ”Automatically keep my Mac up to date.” Your Mac will notify you when updates require it to restart, so you can always choose to install those later.
How to get updates for earlier macOS versions
If you're using an earlier macOS, such as macOS High Sierra, Sierra, El Capitan, or earlier,* follow these steps to keep it up to date:
- Open the App Store app on your Mac.
- Click Updates in the App Store toolbar.
- Use the Update buttons to download and install any updates listed.
- When the App Store shows no more updates, the installed version of macOS and all of its apps are up to date. That includes Safari, iTunes, iBooks, Messages, Mail, Calendar, Photos, and FaceTime. Later versions may be available by upgrading your macOS.
To automatically download updates in the future, choose Apple menu > System Preferences, click App Store, then select ”Download newly available updates in the background.” Your Mac will notify you when updates are ready to install.
* If you're using OS X Lion or Snow Leopard, get OS X updates by choosing Apple menu > Software Update.
How to get updates for iOS
Learn how to update your iPhone, iPad, or iPod touch to the latest version of iOS.
Learn more
- Learn how to upgrade to the latest version of macOS.
- Find out which macOS your Mac is using.
- You can redownload apps that you previously downloaded from the App Store.
- Your Mac doesn't automatically download large updates when it's using a Personal Hotspot.
Many assembly tutorials and books doesn’t coverhow to write a simple assembly program on the Mac OS X.Here are some baby steps that can help people whoare also interested in assembly to get startedeasier.
Mach-O file format
To get started on writing OSX assembly, you need tounderstand OSX executable file format – the Mach-Ofile format. It’s similar to ELF, but insteadof sections of data, bss, and text, it has segments thatcontains sections.
A common assembly in Linux like
would translate into this in Mach-O
Mach-O is pretty flexible. You can embed a
cstring
section in your __TEXT
segment insteadof putting it in __DATA,__data
. Actually this isthe default behavior that compiler does on your Mac.Hello Assembly
Now we know how to translate common linux assemblyto mac, let’s write a basic program – do a system callwith an exit code.
On x86 you do a system call by
int x80
instruction. On64 bit machine, you do this by syscall
. Here’s the samplecode:you can compile the code by the following commands:
To perform a system call, you put the system call number in
%eax
, and put the actual exit code to %ebx
. The systemcall number can be found in /usr/include/sys/syscall.h
.The system call number need to add an offset
0x2000000
, becauseOSX has 4 different class of system calls. You can find the referencehere XNU syscall.System call by using wrapper functions
If you’re like me that had no assembly background, you mightfeel that
syscall
is alien to you. In C, we usually usewrapper functions to perform the call:Now we call a
libc
function instead of performing a systemcall. To do this we need to link to libc by passing -lc
to linker ld
. There are several things you need to doto make a function call. Call frame
We need to prepare the stack before we call a function. Elseyou would probably get a segmentation fault.The values in
%rsp
and %rbp
is used to preserve frame information.To maintain the stack, you first push the base register %rbp
onto the stack by pushq %rbp
;then you copy the stack register %rsp
to the base register.If you have local variables, you subtract
%rsp
for space.Remember, stack grows down and heap grows up.When releasing the frame, you add the space back to %rsp
.A live cycle of a function would look like this:
The stack size can be set at link time. On OSX, below are theexample parameters you can pass to
ld
to set the stack size:When setting the stack size, you also have to set the stack address.On the System V Application Binary Interface it says
Although the AMD64 architecture uses 64-bit pointers, implementationsare only required to handle 48-bit addresses. Therefore, conforming processes may onlyuse addresses from
0x00000000 00000000
to 0x00007fff ffffffff
I don’t know a good answer of how to chose a good stack address.I just copy whatever a normal code produces.
Osx For Intel Macbook Pro
Parameters passing
The rules for parameter passing can be found in System VApplication Binary Interface:
- If the class is MEMORY, pass the argument on the stack.If the size of an object is larger than four eight bytes, orit contains unaligned fields, it has class MEMORY.
- If the class is INTEGER, the next available register of the sequence
%rdi
,%rsi
,%rdx
,%rcx
,%r8
and%r9
is used. - If the class is SSE, the next available vector register is used, the registersare taken in the order from
%xmm0
to%xmm7
.
The
exit()
function only need one integer parameter, therefore we putthe exit code in %edi
. Since the parameter is type int
, we use 32 bitvariance of register %rdi
and the instruction is movl
(mov long) insteadof movq
(mov quad).Hello world
Osx For Intel Mac Pro
Now we know the basics of how to performa system call, and how to call a function.Let’s write a hello world program.
The global variable
str
can only be accessed through GOT(Global Offset Table). And the GOT needs to be access fromthe instruction pointer %rip
. For more curious you canread Mach-O Programming Topics: x86-64 Code Model.Osx For Intel Macbook
The register used for
syscall
parameters are a littlebit different than the normal function call.It uses %rdi
, %rsi
, %rdx
, %r10
, %r8
and %r9
.You cannot pass more than 6 parameters in syscall
, norcan you put the parameters on the stack.Hello world using printf
Now you know the basics of assembly. A hello worldexample using printf should be trivial to read:
Conclusion
The 64 bit assembly looks more vague than the tutorialswritten in X86 assembly. Once you know these basic differences,it’s easy for you to learn assembly in depth on your own,even if the material is designed for x86. I highly recommendthe book “Programming from the ground up”. It is well writtenfor self study purpose.
References
Osx For Intel Mac Os
- OS X Assembler Reference Assembler Directives
- Book: Programming from the ground up.