source: mainline/kernel/arch/ia32/src/boot/vesa_prot.inc@ 3bacee1

#ifdef CONFIG_FB

#define MBINFO_BIT_CMDLINE      2
#define MBINFO_OFFSET_CMDLINE   16

        /* Copy real mode VESA initialization code */

        pm_status $status_vesa_copy

        mov $vesa_init, %esi
        mov $VESA_INIT_SEGMENT << 4, %edi
        mov $e_vesa_init - vesa_init, %ecx
        rep movsb

        /* Check for multiboot command line */

        pm_status $status_multiboot_cmdline

        mov multiboot_eax, %eax
        cmp $MULTIBOOT_LOADER_MAGIC, %eax
        jne no_cmdline

        mov multiboot_ebx, %ebx
        mov (%ebx), %eax
        bt $MBINFO_BIT_CMDLINE, %eax
        jnc no_cmdline

        /* Skip the kernel path in command line */

        mov MBINFO_OFFSET_CMDLINE(%ebx), %esi

        skip_loop:
                lodsb

                cmp $0, %al
                je no_cmdline

                cmp $' ', %al
                je skip_loop_done

                jmp skip_loop
        skip_loop_done:

        space_loop:
                mov (%esi), %al

                cmp $0, %al
                je no_cmdline

                cmp $' ', %al
                jne space_loop_done

                inc %esi
                jmp space_loop
        space_loop_done:

        /* Copy at most 23 characters from command line */

        mov $VESA_INIT_SEGMENT << 4, %edi
        add $default_mode - vesa_init, %edi
        mov $23, %ecx

        cmd_loop:
                lodsb
                stosb

                cmp $0, %al
                je cmd_loop_done

                loop cmd_loop
        cmd_loop_done:

        /* Zero termination */

        xor %eax, %eax
        stosb

        no_cmdline:

        /* Jump to the real mode */

        pm_status $status_vesa_real

        mov $VESA_INIT_SEGMENT << 4, %edi
        jmpl *%edi

        vesa_meeting_point:
                /* Returned back to protected mode */

                /*
                 * Initialize Global Descriptor Table and
                 * Interrupt Descriptor Table registers
                 */
                lgdtl bootstrap_gdtr
                lidtl bootstrap_idtr

                movzx %ax, %ecx
                mov %ecx, KA2PA(bfb_scanline)

                shr $16, %eax
                mov %ax, KA2PA(bfb_bpp)

                movzx %bx, %ecx
                mov %ecx, KA2PA(bfb_height)

                shr $16, %ebx
                mov %ebx, KA2PA(bfb_width)

                mov %dl, KA2PA(bfb_green_pos)

                shr $8, %edx
                mov %dl, KA2PA(bfb_green_size)

                shr $8, %edx
                mov %dl, KA2PA(bfb_red_pos)

                shr $8, %edx
                mov %dl, KA2PA(bfb_red_size)

                mov %esi, %edx
                mov %dl, KA2PA(bfb_blue_pos)

                shr $8, %edx
                mov %dl, KA2PA(bfb_blue_size)

                mov %edi, KA2PA(bfb_addr)
#endif