ARM Assembly: Lesson 10 (Function Calls)

Welcome to Lesson 10 of the ARM Assembly Series from LaurieWired!
In this video, we learn how to call and return from functions in ARM assembly. We also learn how to pass parameters using registers and how to save their values on the stack.
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Timestamps:
00:00 Intro
00:57 Example C code
01:47 ARM Calling Conventions
03:12 Return Values
03:47 Method Invocation
05:15 Branching out of Function
06:12 Saving Register State
07:10 The Stack
09:57 Stepping through the Disassembly
13:43 Recap
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Links Mentioned in Video:
CPULator:
cpulator.01xz.net/?sys=arm
ARM Mnemonic Extensions:developer.arm.com/documentati...
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laurieWIRED Website:
lauriewired.com
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github.com/LaurieWired
laurieWIRED HN:
news.ycombinator.com/user?id=...
laurieWIRED Reddit:
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[@0xReip]

I like watching your channel so I practice my English listening and learn more about ARM as well

[@manawardhana]

Great explanation. I didn't find any gaps. Brilliant! Thank you! 👏👏👏🙏

[@IamDejaVu]

Such a great video! Keep it up :)

[@ArjanvanVught]

Thanks for all your effort! Great content!

[@neilclay5835]

Great series

[@_orangutan]

The sickest of intros.

[@AbdurahmonMirobidov]

thanks for this amazing content

[@bikdigdaddy]

i saw u on linkedin and your content seems amazing too. hoping to learn from you. also that lain reference is epic ;)

[@MovieVertigo]

Interesting to see how things have changed since the Archimedes/Risc PC era (Arm 2/3). I have MOV PC,R14 etched into my brain for returning from a function call 😁

[@aa_yu_s_h]

U are the one.

[@MauroPanigada]

8:58 from the fogs of 68k assembly programming on the Amiga: it was a (sort of?) rule that the callee had to save the registers it used (except for those considered "scratch registers"), so that every subroutine usually started with movem.l d2-d7/a2-a6, -(sp) and ended with movem.l (sp)+, d2-d7/a2-a6 just before the rts (return instruction - 68k "branch/jump to subroutine" pushes the return address on the stack - pointed by a7, alias sp just to make it clear we are dealing with the stack). And if you, as the writer of the subroutine, knew that you were not going to overwrite any register (beyond d0-d1 and a0-a1), you could spare the movem instruction. I think I prefer a calling convention that forces this guarantees making the callee take care of not overwriting certain registers, rather than making the caller always worry about it.

[@AEONIC_MUSIC]

how was this intro made? its amazing

[@biplavsingh5026]

What is I flag in cpsr?🤔

[@tear728]

Something about the frequency of your voice tickles my ears 😂👂

[@ahmedmani1051]

7:30 the vietnam flashback took me off guard

[@ThiagoSTeixeir4]

Present day, present time Hahahaha