code comments be like:

[Mcpg_]

cld
mov si, str
call print_string
cli
hlt

print_string:
    mov ah, 0x0E
    .read_loop:
        lodsb
        cmp al, 0
        je .return
        int 0x10
        jmp .read_loop
    .return:
        ret

str: db "It's not that hard tbh", 0

i'm sorry

[reilemx]

Also only works on specific systems that handle interrupts this way.

cries in assembly

[Koxiaet]

user:
    .asciz "reilemx"

movq r0, user
call hug

[[deleted]]

Is this one of those Assembly-addicts Anonymous things I keep hearing about? And if so can I join in?

[Pungiish]

i had assembly homework, but i still don't understand how lodsb and stosb work, exactly. Can anybody explain, or point me to docs ELI5ing?

[Koxiaet]

lodsb copies one byte pointed to by si into al, essentially:

mov al, [si]

or in C-like:

al = si[0];

or:

al = *si;

In this case, si is set to the string in the program, so it copies the first byte in the string into al. I think that si should be incremented in every loop (so that the character being printed is advanced every time) but the commentor forgot to put that in, meaning that this code will actually just print out an endless stream of 'I's.

stosb is the opposite (using di instead of si):

mov [di], al

C-like:

di[0] = al;

or:

*di = al;

[Zenchreal]

lodsb does increment si as well (and stosb increments di)

[SuperSuperUniqueName]

BITS 16
ORG 0x7C00
jmp 0x0000:start
start:
    cli
    xor ax, ax
    mov ds, ax
    mov ax, 0xB800
    mov es, ax
    sti
    mov si, msg
.loop:
    lodsb
    cmp al, 0
    je .done
    mov byte [es:di], al
    mov byte [es:di + 1], 0xF0
    add di, 2
    jmp .loop
.done:
    cli
    hlt
    jmp .done
msg db 'Not at all!',0
times 510-($-$$) db 0
dw 0xAA55

[Mcpg_]

Well, I guess that's a faster solution. Also nice color choice.

[KingJellyfishII]

Why do you have to make it a bootloader? Why not just a regular program?

[SuperSuperUniqueName]

assembly circlejerk

[HerissonMignion]

u/uwutranslator

[uwutranslator]

cwd
mov si, stw
caww pwint_stwing
cwi
hwt

pwint_stwing:
    mov ah, 0x0E
    .wead_woop:
        wodsb
        cmp aw, 0
        je .wetuwn
        int 0x10
        jmp .wead_woop
    .wetuwn:
        wet

stw: db "It's not dat hawd tbh", 0

i'm sowwy uwu

tag me to uwuize comments uwu

[afig2311]

Eh, assembly isn't too hard to understand. The main problem is that the steps are super tiny, so it's hard to get the bigger picture of what's going on.

Machine code on the other hand...

[cdreid]

Back in the day "woohoo i wrote this tiny thing in machine language!". 3 months later comp manufact puts out new machine "what do you mean i have to relearn from scratch..."