assembly - Boot Loader in Linux -


i hve coded following bootloader program.but there problem.

;=================================================================== ;following incomplete code of boot-loader blanks(.....) ;replace each blank appropriate word, words or character ;===================================================================  [org 0x7c00]  ;============================================================== ;msg2, msg3 , msg4 should describe right order of typical ;boot-loading functionality (i.e. basially boot-loader does?)  msg1 dd '1. boot loader starts ', 0 msg2 dq '2. initialize hardware', 0 msg3 dq '3. pass abstraction of initialize hardware', 0 msg4 dq '4. execute kernel', 0 msg5 dq '5. boot loader exits ', 0 ;==============================================================  ;============================================================== ;printing messages (msg1, msg2, .....)  mov si, msg1 call printstring ;call print string procedure mov si, msg1 call printstring ;call print string procedure mov si, msg2 call printstring ;call print string procedure mov si , msg3 call printstring ;call print string procedure mov si , msg4 call printstring ;call print string procedure mov si, msg5 call printstring ;call print string procedure  jmp $ ;infinite loop here ;===============================================================  ;=============================================================== printcharacter: ;procedure print character on screen  mov ah, 0x0e mov bh, 0x00 mov bl, 0x07  int 0x10 ret ;===============================================================  ;=============================================================== printstring: ;procedure print string on screen  mov al , [si] call printcharacter nextchar: inc si mov al , [si] cmp al , 0 jz exit_function call printcharacter jmp nextchar exit_function: ret ;===============================================================  ;===============================================================  times (495) - ($ - $$) db 0 db 0 dw 0xaa52 dd 0xaa53 dq 0xaa54 dw 0xaa55 ;end of boot-loader  ;===

it doesn't output first message.how can correct it?.thank you.

for defining strings, should using db (or possibly dw) instead of dd/dq.

oh, , should have jump actual code before string data, or cpu think strings code should executed.


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