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Cleaning BSS in ARMv8-A

I am trying to write good and basic 'cleaning bss' code for my bootloader but AI's arguing me and I don't know what to do..

My code is this:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

ldr x2, =__bss_start

ldr x3, =__bss_size

cbz x3, start_main

udiv x3, x3, #8

mul x4, x3, #8

sub x5, __bss_size, x4

clear_bss:

cbz x3, check_remainder

str xzr, [x2], #8

sub x3, x3, #1

cbnz x3 clear_bss

check_remainder:

cbz x5, start_main

str xzr, [x2], #1

cbnz x5, check_remainder

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

But AI's forcing me to write instead of it:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

ldr x2, =__bss_start
ldr x3, =__bss_size
cbz x3, start_main

clear_bss:
str xzr, [x2], #8
sub x3, x3, #1

cbnz x3, clear_bss

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

They say my code sucks, so complex and their code is basic and optimised.
What should I do??___###

Okay, Im reporting my question. I just write a question and think about it, update things and someone reports it..

Parents

0 Mahmud Esad Çıtak 6 months ago

ChatGPT is offering me different solutions, making mistakes and just updating 1 line for every iteration (my long question)
I'm feeling really crazy

we have 9 bytes for clean.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
chatGPT_cleaning:

cmp x3, #8

blt there_is_a_remainder

clean_aggressively:

str xzr, [x2], #8
sub x3, x3, #8

cbz x3, cleaning_done

b clean_aggressively

there_is_a_remainder:

cbz x3, cleaning_done

str xzr, [x2], #1

sub x3, x3, #1

b there_is_a_remainder

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

-> Cleaned 8 bytes of 9 bytes.
-> Cleaned 8 bytes of 1 bytes. ???What happens here, code is clean 8 bytes but gpt says if there is a 8x+k for x =0, it cleans just k???

Or it really cleans 8 bytes of 1 bytes, some hotel rooms are raided?

Maybe we can use a security prosedure, adding an extra 8 bytes to end of the bss section. So we don't have to calculate remainders.

continue:
str xzr, [x2], #8
sub x3, x3, #8
cbnz x3, continue

But now the problem is negative values of size on x3 register.
Uhh...

I'll write an article about this problem..

As a real engineer, please comment and write some advise, what should I do exactly?
I think my first code improved to two functions (one is for big size values and other one is smalls) is the answer just now, I don't know....
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0 Mahmud Esad Çıtak 6 months ago

ChatGPT is offering me different solutions, making mistakes and just updating 1 line for every iteration (my long question)
I'm feeling really crazy

we have 9 bytes for clean.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
chatGPT_cleaning:

cmp x3, #8

blt there_is_a_remainder

clean_aggressively:

str xzr, [x2], #8
sub x3, x3, #8

cbz x3, cleaning_done

b clean_aggressively

there_is_a_remainder:

cbz x3, cleaning_done

str xzr, [x2], #1

sub x3, x3, #1

b there_is_a_remainder

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

-> Cleaned 8 bytes of 9 bytes.
-> Cleaned 8 bytes of 1 bytes. ???What happens here, code is clean 8 bytes but gpt says if there is a 8x+k for x =0, it cleans just k???

Or it really cleans 8 bytes of 1 bytes, some hotel rooms are raided?

Maybe we can use a security prosedure, adding an extra 8 bytes to end of the bss section. So we don't have to calculate remainders.

continue:
str xzr, [x2], #8
sub x3, x3, #8
cbnz x3, continue

But now the problem is negative values of size on x3 register.
Uhh...

I'll write an article about this problem..

As a real engineer, please comment and write some advise, what should I do exactly?
I think my first code improved to two functions (one is for big size values and other one is smalls) is the answer just now, I don't know....
Cancel
Vote up 0 Vote down

Cancel

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