search for: ljmpw

...set_lo */ pushw %es /* -10: es:di -> $PnP header */ pushw %di /* -12: es:di -> $PnP header */ movw %bp, %ds movw %bp, %es ADJUST_DRIVE pushw %dx /* -14: dl -> drive number */ /* Copy down to 0:0x600 */ movw $0x7c00, %si movw $_start, %di movw $(512/2), %cx rep; movsw ljmpw $0, $next next: /* Check to see if we have EBIOS */ pushw %dx /* drive number */ movb $0x41, %ah /* %al == 0 already */ movw $0x55aa, %bx xorw %cx, %cx xorb %dh, %dh stc int $0x13 jc 1f cmpw $0xaa55, %bx jne 1f andw $1,%cx /* Bit 0 = fixed disk subset */ jz 1f /* We have EBIOS; pa...

...@@ -67,6 +67,7 @@ _start: movw %ax, %ss movw $stack, %sp movw %sp, %si + movw %sp, %bp /* needed later if drive number is to be forced due to Ctrl key being pressed */ pushw %es /* es:di -> $PnP header */ pushw %di pushw %dx /* dl -> drive number */ @@ -82,6 +83,15 @@ _start: ljmpw $0, $next next: + /* Provide a way for the user to force boot from first hard-disk by pressing a Ctrl key */ +get_shift_keys: /* Provide a way for the user to force CHS addressing mode by pressing either Shift key */ + testb $0x04, 0x0417 /* I/O memory-mapped keyboard shift flags: control key...

...set_lo */ pushw %es /* -10: es:di -> $PnP header */ pushw %di /* -12: es:di -> $PnP header */ movw %bp, %ds movw %bp, %es ADJUST_DRIVE pushw %dx /* -14: dl -> drive number */ /* Copy down to 0:0x600 */ movw $0x7c00, %si movw $_start, %di movw $(512/2), %cx rep; movsw ljmpw $0, $next next: /* Check to see if we have EBIOS */ pushw %dx /* drive number */ movb $0x41, %ah /* %al == 0 already */ Here it claims that al is zero. This is not true. Especially if you look at the line that says "cmpl $0x58504721, %eax" earlier. That code is looking for a sign...

Thomas Schmitt wrote: > I have some problems understanding the details of the program's flow. > > - The code inside PARTITION_SUPPORT is supposed to be inactive with > MBR isohdpfx.bin. It belongs to isohybrid --partok which is equivalent > to MBRs isohdppx*.bin. Debian uses isohdpfx.bin. Yes. isohdpfx.bin is generated from isohdpfx.S in which PARTITION_SUPPORT is not

...BIOS flag */ /* Get (C)HS geometry */ movb $0x08, %ah int $0x13 + + /* here we computer CHS values or just do some dummy computation for EBIOS */ andw $0x3f, %cx /* Sector count */ popw %bx /* EBIOS flag */ pushw %cx /* -16: Save sectors on the stack */ @@ -223,9 +257,15 @@ next: ljmpw $0, $isolinux_start_hybrid bad_signature: - call error + call print_string .ascii "isolinux.bin missing or corrupt.\r\n" +boot_failure: + int $0x18 /* Boot failure */ +die: + hlt + jmp die + /* * read_sector: read a single sector pointed to by %eax to %es:%bx. * CF is set on...

...nable interrupts */ + cld /* increment direction for relocation operation */ +relocate: + movw $_start, %di /* destination address for relocation */ + movw $(512/2), %cx /* number of words to relocate */ + rep; movsw /* repeat the move CX times, incrementing SI and DI after each move */ + + ljmpw $0, $get_shift_keys /* far jump to ensure CS:IP are set correctly to 0000:0600+get_shift_keys */ + /* rather than the current CS:IP which will be based on 0x7C00 */ + +get_shift_keys: /* Provide a way for the user to force CHS addressing mode by pressing either Shift key */ + movb $0x02,...

...nable interrupts */ + cld /* increment direction for relocation operation */ +relocate: + movw $_start, %di /* destination address for relocation */ + movw $(512/2), %cx /* number of words to relocate */ + rep; movsw /* repeat the move CX times, incrementing SI and DI after each move */ + + ljmpw $0, $get_shift_keys /* far jump to ensure CS:IP are set correctly to 0000:0600+get_shift_keys */ + /* rather than the current CS:IP which will be based on 0x7C00 */ + +get_shift_keys: /* Provide a way for the user to force CHS addressing mode by pressing either Shift key */ + movb $0x02,...

...nable interrupts */ + cld /* increment direction for relocation operation */ +relocate: + movw $_start, %di /* destination address for relocation */ + movw $(512/2), %cx /* number of words to relocate */ + rep; movsw /* repeat the move CX times, incrementing SI and DI after each move */ + + ljmpw $0, $get_shift_keys /* far jump to ensure CS:IP are set correctly to 0000:0600+get_shift_keys */ + /* rather than the current CS:IP which will be based on 0x7C00 */ + +get_shift_keys: /* Provide a way for the user to force CHS addressing mode by pressing either Shift key */ + testb $0x04,...