#Bochs not loading latest image software
So, I began looking for a software solution which would allow me to run on my SPARCstation the handful of PC programs I used. Well, that got old quick! Having two keyboards, two monitors, and two computers on one's desk consumes more than desktop real estate-it takes much more time to maintain and introduces frustrations from the disparate OS designs. Occasionally, though, I found myself firing up the ol' PC on my desk, using MS Word to crank out documentation or a memo, or to run one of a handful of smaller utility programs I purchased years ago. I could do almost everything computer related, including e-mail interaction, system administration, net surfing, network Doom (I confess-it was me who circulated that hack so you could run Doom on Solaris 2.3), all on the same machine I used for software development. Bochs just hungs just after printing "jumping to second stage"( Print call just before jumping to second stage). It seems second stage is not getting loaded at 0x500.
I am trying to find and load second stage bootloader at memory address 0x500. MsgFailure db 0x0D, 0x0A, "ERROR : Press Key to Reboot", 0x0A, 0x00 ImageName db "KRNLDR SYS" must be 11 bytes Retf far return, both of the above value will be used
Test ax, 0x0001 if this was odd cluster => lower 12 bits, else =>higher 12 bits will be used Mov bx, 0x0200 location of FAT in memoryĪdd bx, cx we moved 3/2*cluster no bytes from start compute next cluster, remember cluster entries are of 12 bits = 3/2 bytes load image file into memory at 0050:0000 => 0x500) location of FAT in ax = no of reserved Sectors compute size of FAT and store in cx = no of FAT * sectors per FAT Mov di, 0x0200 address of root table in memory read root directory into memory 0x7C0:0x0200 = 7C00+0200 location root directory = reserved sectors + (no of FATS * sectors per FAT)Īdd word, cx start of data sector size of root directory = 32*(no of root entries)/(bytes per sector) SECTORS absoluteTrack = logical sector / (sectors per track * no of heads) absolute head = (logical sector / sectors per track) % no of heads absolute sector = (logical sector % sector per track) + 1 Mov ah, 0x02 prepare bios read interruptĪdd bx, word next read buffer locationĪdd ax, word base of data sectors
Mov di, 0x0005 we will try 5 times if failedĬall LBACHS we will get absolute sector, absolute head and absolute track information from here
Mov ah, 0eh prepare fro bios vedio interuppt call string pointed by ds:si, terminated by 0 must start 3 bytes after start (jmp main is of 3 byte)īpbOEM db "My OS " OEM identifier (Cannot exceed 8 bytes!) I am following brokenthorn OS development series, until now I am able sucessfully run bootloader stage1 but there is some issue with loading second stage bootloader from FAT12 floppy in bochs emulator on linux machine(ubuntu 16.04) (It works fine in virtual box though).
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