Stefan? I think you wanted to Ack this as well. Alex will then commit.
Alex Beregszaszi wrote:
> If you say ack, let me commit this, as I missed my last opportunity to
> commit :)
> this patch changes the real_mode_switch_call_vga() function to jump to
> the addr given as an argument instead the hardcoded 0xc000.
>
> Also it changes the function to inline assembly and passes the arguments
> through that.
Can you commit the changes above as separate revisions? First the inline
assembly change, then the variable addr stuff. This makes the changes
easier to follow.
> Signed-off-by: Alex Beregszaszi <[EMAIL PROTECTED]>
Acked-by: Carl-Daniel Hailfinger <[EMAIL PROTECTED]>
Carl-Daniel
> Index: util/x86emu/vm86.c
> ===================================================================
> --- util/x86emu/vm86.c (revision 494)
> +++ util/x86emu/vm86.c (working copy)
> @@ -5,6 +5,7 @@
> * Copyright (C) 2001 University of California. LA-CC Number 01-67.
> * Copyright (C) 2005 [EMAIL PROTECTED]
> * Copyright (C) 2007 coresystems GmbH
> + * Copyright (C) 2007 Siqon Ltd. (written by Alex Beregszaszi)
> *
> * This program is free software; you can redistribute it and/or modify
> * it under the terms of the GNU General Public License as published by
> @@ -98,7 +99,7 @@
> );
>
> /* The address arguments to this function are PHYSICAL ADDRESSES */
> -static void real_mode_switch_call_vga(unsigned long devfn)
> +static void real_mode_switch_call_vga(unsigned long devfn, unsigned long
> addr)
> {
> __asm__ __volatile__ (
> /* paranoia -- does ecx get saved? not sure.
> @@ -106,16 +107,12 @@
> */
> " pushal \n"
> /* save the stack */
> - " mov %esp, __stack \n"
> + " mov %%esp, __stack \n"
> " jmp 1f \n"
> "__stack: .long 0 \n"
> "1:\n"
> - /* get devfn into %ecx */
> - " movl %esp, %ebp \n"
> - // FIXME: why is this 8?
> - " movl 8(%ebp), %ecx \n"
> /* load 'our' gdt */
> - " lgdt %cs:__mygdtaddr \n"
> + " lgdt %%cs:__mygdtaddr \n"
>
> /* This configures CS properly for real mode. */
> " ljmp $0x28, $__rms_16bit\n"
> @@ -128,17 +125,17 @@
> * configurations (limits, writability, etc.) once
> * protected mode is turned off.
> */
> - " mov $0x30, %ax \n"
> - " mov %ax, %ds \n"
> - " mov %ax, %es \n"
> - " mov %ax, %fs \n"
> - " mov %ax, %gs \n"
> - " mov %ax, %ss \n"
> + " mov $0x30, %%ax \n"
> + " mov %%ax, %%ds \n"
> + " mov %%ax, %%es \n"
> + " mov %%ax, %%fs \n"
> + " mov %%ax, %%gs \n"
> + " mov %%ax, %%ss \n"
>
> /* Turn off protection (bit 0 in CR0) */
> - " movl %cr0, %eax \n"
> - " andl $0xFFFFFFFE, %eax \n"
> - " movl %eax, %cr0 \n"
> + " movl %%cr0, %%eax \n"
> + " andl $0xFFFFFFFE, %%eax \n"
> + " movl %%eax, %%cr0 \n"
>
> /* Now really going into real mode */
> " ljmp $0, $__rms_real\n"
> @@ -148,33 +145,49 @@
> * That way we can easily share it between real and
> * protected, since the 16-bit ESP at segment 0 will
> * work for any case. */
> - " mov $0x0, %ax \n"
> - " mov %ax, %ss \n"
> - " movl $0x1000, %eax \n"
> - " movl %eax, %esp \n"
> + " mov $0x0, %%ax \n"
> + " mov %%ax, %%ss \n"
> + " movl $0x1000, %%eax \n"
> + " movl %%eax, %%esp \n"
>
> /* Load our 16 it idt */
> - " xor %ax, %ax \n"
> - " mov %ax, %ds \n"
> + " xor %%ax, %%ax \n"
> + " mov %%ax, %%ds \n"
> " lidt __myidt \n"
>
> /* Dump zeros in the other segment registers */
> - " mov %ax, %es \n"
> - " mov %ax, %fs \n"
> - " mov %ax, %gs \n"
> - " mov $0x40, %ax \n"
> - " mov %ax, %ds \n"
> - " mov %cx, %ax \n"
> + " mov %%ax, %%es \n"
> + " mov %%ax, %%fs \n"
> + " mov %%ax, %%gs \n"
> + " mov $0x40, %%ax \n"
> + " mov %%ax, %%ds \n"
> + " mov %%cx, %%ax \n"
>
> /* run VGA BIOS at 0xc000:0003 */
> - " lcall $0xc000, $0x0003\n"
> +/* " lcall $0xc000, $0x0003 \n"*/
>
> + /* calculate addr */
> + " mov %%edx, %%ebx \n"
> + " add $3, %%ebx \n"
> + " and $0xffff, %%ebx \n"
> + /* calculate segment */
> + " and $0xf0000, %%edx \n"
> + " shr $4, %%edx \n"
> +
> + " pushw %%dx \n"
> + " pushw %%bx \n"
> + " mov %%esp, %%ebp \n"
> + /* idea from bochs bios' rom_scan */
> + /* call far ss:[bp+0] */
> + " .byte 0xff, 0x5e, 0x00 \n"
> + " add $4, %%esp \n"
> +
> /* If we got here, just about done.
> * Need to get back to protected mode
> */
> - " movl %cr0, %eax \n"
> - " orl $0x0000001, %eax\n" /* PE = 1 */
> - " movl %eax, %cr0 \n"
> + " movl %%cr0, %%eax \n"
> + " orl $0x0000001, %%eax\n" /* PE = 1 */
> + " movl %%eax, %%cr0 \n"
>
> /* Now that we are in protected mode
> * jump to a 32 bit code segment.
> @@ -182,21 +195,23 @@
> " data32 ljmp $0x10, $vgarestart\n"
> "vgarestart:\n"
> " .code32\n"
> - " movw $0x18, %ax \n"
> - " mov %ax, %ds \n"
> - " mov %ax, %es \n"
> - " mov %ax, %fs \n"
> - " mov %ax, %gs \n"
> - " mov %ax, %ss \n"
> + " movw $0x18, %%ax \n"
> + " mov %%ax, %%ds \n"
> + " mov %%ax, %%es \n"
> + " mov %%ax, %%fs \n"
> + " mov %%ax, %%gs \n"
> + " mov %%ax, %%ss \n"
>
> /* restore proper gdt and idt */
> - " lgdt %cs:gdtarg \n"
> + " lgdt %%cs:gdtarg \n"
> " lidt idtarg \n"
>
> ".globl vga_exit \n"
> "vga_exit: \n"
> - " mov __stack, %esp \n"
> + " mov __stack, %%esp \n"
> " popal \n"
> + :
> + : "c" (devfn), "d" (addr)
> );
> }
>
> @@ -315,8 +330,8 @@
> for (i = 0x400; i < 0x500; i++) {
> *(unsigned char *) i = 0;
> }
> -
> - real_mode_switch_call_vga((dev->bus->secondary << 8) |
> dev->path.u.pci.devfn);
> +
> + real_mode_switch_call_vga((dev->bus->secondary << 8) |
> dev->path.u.pci.devfn, addr);
> }
>
>
>
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