Dump Registers in A boot sector

dump.asm

; https://github.com/appusajeev/os-dev-16/blob/master/reg.asm
; This code is a slightly modified version of the above. 
; This code dumps the registers in a single boot sector.
; Compile and run with the 2 following commands:
; nasm -f bin dump.asm -o dump
; qemu-system-i386 -fda dump
; You can also do it without -fda if you hate floppy disks for some reason.



[bits 16]
[org 0x7c00]
push ax
mov ax,cs
mov ds,ax
mov es,ax
pop ax
;push testt
;call print
push axx
push ax
call tohex

push bxx
push bx
call tohex

push cxx
push cx
call tohex

push dxx
push dx
call tohex

push css
push cs
call tohex

push dss
push ds
call tohex

push sss
push ss
call tohex

push ess
push es
call tohex

push spp
push sp
call tohex

push sii
push si
call tohex

push dii
push di
call tohex

push gss
push gs
call tohex


push fss
push fs
call tohex


jmp 0x1000:0


print:  ;print a zero terminated string
        pusha
        mov bp,sp
        mov si,[bp+18]
        cont:
                lodsb
                or al,al
                jz dne
                mov ah,0x0e
                mov bx,0
                mov bl,7
                int 10h
                jmp cont
        dne:
                mov sp,bp
                popa
                ret




tohex:
        pusha
        mov bp,sp
        mov dx, [bp+20]
        push dx
        call print
        mov dx,[bp+18]

        mov cx,4
        mov si,hexc
        mov di,hex+2

        stor:

        rol dx,4
        mov bx,15
        and bx,dx
        mov al, [si+bx]
        stosb
        loop stor
        push hex
        call print
        mov sp,bp
        popa
        ret
        
hex db "0x0000",10,13,0
hexc db "0123456789ABCDEF"
testt db "hello",10,13,0
css db "CS: ",0
dss db "DS: ",0
sss db "SS: ",0
ess db "ES: ",0
gss db "GS: ",0
fss db "FS: ",0
axx db "AX: ",0
bxx db "BX: ",0
cxx db "CX: ",0
dxx db "DX: ",0
spp db "SP: ",0
bpp db "BP: ",0
sii db "SI: ",0
dii db "DI: ",0

times 510 - ($-$$) db 0
dw 0xaa55