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#ifndef CYGONCE_HAL_PCMB_INC
#define CYGONCE_HAL_PCMB_INC
##=============================================================================
##
##      pcmb.inc
##
##      PC platform support
##
##=============================================================================
#####ECOSGPLCOPYRIGHTBEGIN####
## -------------------------------------------
## This file is part of eCos, the Embedded Configurable Operating System.
## Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
##
## eCos is free software; you can redistribute it and/or modify it under
## the terms of the GNU General Public License as published by the Free
## Software Foundation; either version 2 or (at your option) any later version.
##
## eCos is distributed in the hope that it will be useful, but WITHOUT ANY
## WARRANTY; without even the implied warranty of MERCHANTABILITY or
## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
## for more details.
##
## You should have received a copy of the GNU General Public License along
## with eCos; if not, write to the Free Software Foundation, Inc.,
## 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
##
## As a special exception, if other files instantiate templates or use macros
## or inline functions from this file, or you compile this file and link it
## with other works to produce a work based on this file, this file does not
## by itself cause the resulting work to be covered by the GNU General Public
## License. However the source code for this file must still be made available
## in accordance with section (3) of the GNU General Public License.
##
## This exception does not invalidate any other reasons why a work based on
## this file might be covered by the GNU General Public License.
##
## Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
## at http://sources.redhat.com/ecos/ecos-license/
## -------------------------------------------
#####ECOSGPLCOPYRIGHTEND####
##=============================================================================
#######DESCRIPTIONBEGIN####
##
## Author(s):   jskov
## Contributors:jskov, pjo, nickg
## Date:        1999-01-07
## Purpose:     PC platform support
## Description: This file contains any PC specific assembler macros needed to
##              run eCos on a standard i386 PC.
##
##
######DESCRIPTIONEND####
##
##=============================================================================


##=============================================================================
## CPU initialization

#ifndef CYGPKG_HAL_I386_CPU_INIT_DEFINED
        
#ifdef CYG_HAL_STARTUP_FLOPPY

#define CYGPKG_HAL_I386_CPU_INIT_DEFINED

        .macro  hal_cpu_init

        /* This code is loaded from a floppy disk when the PC powers up.  */

        .code16

        .extern _end

        sectorsPerTrack = 18
        bytesPerSector = 512
        esPerSector = 32        /* = 512/16 */

        cld                             /* always count up. */

        /* Configure a stack that we can use. */
        
        movl    $_start, %eax
        movw    %ax, %sp
        shr     $4, %eax
        andl    $0xF000, %eax
        movw    %ax, %ss

        /* Ask the BIOS for info about the amount of RAM available.  We push
         * these onto the stack for later use.
         */
        
        xorl    %eax, %eax
        movb    $0x88, %ah              /* Get the amount of extended memory. */
        int     $0x15
        shl     $10, %eax
        pushl   %eax

        xorl    %eax, %eax
        int     $0x12                   /* Get the amount of standard memory. */
        shl     $10, %eax
        pushl   %eax

        /* reset floppy */
        movb $0,%ah
        movb $0,%dl
        int $0x13
        jc _error1
        
        /* Read the rest of the image to _start.  This code works by reading
           only one sector at a time to avoid "buffer cross 64k boundary" fatal
           problem... This is slow but should work in almost all situations.
           _start should be aligned on a 512 bytes boundary to be sure.
        */
        
        /* destination pointer es:bx */
        /* With correct alignement, bx should be 0 and es should be a multiple
         * of 32. If not it may cause the "buffer cross 64k boundary" problem
         * (cf above)
         */  
        movl    $_start,%eax
        movw    %ax,%bx
        andw    $0xF,%bx
        shrl    $4,%eax
        movw    %ax, %es

        /* initials head/track/sector */
        movw    $0,%dx
        movw    $1,%cx

        movl    $_edata,%edi
        addl    $(bytesPerSector-1),%edi
        shrl    $4,%edi
        
        jmp     _loadsector

_nextsector:
        movw    %es,%ax
        cmpw    %di,%ax
        jge     _endload
        addw    $esPerSector,%ax
        movw    %ax,%es
        incb    %cl
        cmpb    $sectorsPerTrack, %cl 
        jbe     _loadsector     /* next head ?*/
        movb    $1, %cl
        incb    %dh    
        cmpb    $1, %dh
        je      _loadsector     /* next track ? */
        movb    $0, %dh
        incb    %ch    

_loadsector:

        pushw   %es
        pushw   %di
        movw    $0x0201, %ax
        clc
        int     $0x13
        popw    %di
        popw    %es
        jc _error2

        movw    $(0x0E*256+'.'), %ax    /* print a dot */
        int     $0x10

        /* So go ahead and resume execution at the real starting address.  This
        only serves to move us quickly to the real starting location; and has
        no effect after reading additional tracks.  If we didn't jump after
        reading the first track, then we limit ourselves to reading images of
        30k bytes max before overwriting ourselves at 0x7C00.
        */

        ljmp $0,$_nextsector    

_error1:
        movw    $(0x0E*256+'1'), %ax    /* print a ! */
        int     $0x10   
        jmp     _error

_error2:
        mov     %ah,%al
        pushw   %ax
        shrw    $4,%ax
        andw    $15,%ax
        addw    $0x0E41,%ax
        int     $0x10
        popw    %ax
        andw    $15,%ax
        addw    $0x0E41,%ax
        int     $0x10
        
        movw    $(0x0E*256+'2'), %ax    /* print a ! */
        int     $0x10
        jmp     _error
                
_error:         /* halt on error */
        movw    $(0x0E*256+'!'), %ax    /* print a ! */
        int     $0x10

        cli
        hlt
        jmp _start


        /* Write the 0x55/0xAA signature at the end of the first
        block.  Without this signature the BIOS won't consider this
        block to be bootable.  
        */
        
        . = _start + 510
        .byte   0x55
        .byte   0xAA

_endload:
1:

        /* Lets be nice and wait for the diskette drive motor to go off
         * before continuing. */
        
        movw    $0x40, %ax
        movw    %ax, %es
        movl    $0x40, %ebx
2:      es
        movb    (%bx), %al
        cmpb    $0, %al
        jne     2b

        /* Now we're all loaded up in memory. */

        /* Optionally switch to a high-res video before entering        */
        /* protected mode. The mode is controlled by an option in       */
        /* the RedBoot configuration, which is not readily visible      */
        /* in the application configuration. Therefore RedBoot also     */
        /* performs some information-related BIOS calls, getting the    */
        /* main SVGA BIOS information and the mode-specific             */
        /* information. These are placed in video memory, because       */
        /* nothing else should be touching that and it avoids having    */
        /* some other special buffer shared between RedBoot and the     */
        /* application. The disadvantage is possibly some strange junk  */
        /* visible on the screen after RedBoot has started.             */
#ifdef CYGNUM_HAL_I386_PC_STARTUP_VIDEO_MODE
        movw    $0x4f02, %ax
        movw    $ CYGNUM_HAL_I386_PC_STARTUP_VIDEO_MODE, %bx
        int     $0x10

        /* SVGA information @ 0x000A0000 */
        /* Placing VBE2 at this location before the int10 gives more information */
        movw    $0xA000, %ax
        movw    %ax, %es
        movw    $0x0, %di
        movb    $('V'), %es:0(%di)
        movb    $('B'), %es:1(%di)
        movb    $('E'), %es:2(%di)
        movb    $('2'), %es:3(%di)
        movw    $0x4f00, %ax
        int     $0x10

        /* Information about all supported modes starting @ 0x000A0400  */
        /* ds:si is used to index the main mode table, offset 14        */
        movw    %es:14(%di),%si
        movw    %es:16(%di),%ax
        movw    %ax,%ds

        /* es:di is used for the destination.                           */
        movw    $0xA000,%ax
        movw    %ax,%es
        movw    $0x0400,%di

modes_loop:
        /* The mode table is terminated by a -1 entry                   */
        movw    %ds:0(%si), %cx
        cmpw    $0xffff,%cx
        je      modes_done
        movw    $0x4f01, %ax
        int     $0x10
        addw    $0x0100, %di
        addw    $2,%si
        jmp     modes_loop
modes_done:

        /* Information about the current mode @ 0x000A0200      */
        movw    $0xA000, %ax
        movw    %ax, %es
        movw    $0x0200, %di
        movw    $0x4f01, %ax
        movw    $ CYGNUM_HAL_I386_PC_STARTUP_VIDEO_MODE, %cx
        int     $0x10
#endif

        /* Disable interrupt handling. */
        cli

        /* Load GDTR and IDTR. */

        lgdt    %cs:gdt
        lidt    %cs:idt

        /* Switch to protected mode. */
        movl    %cr0,%eax
        orb     $1, %al
        movl    %eax,%cr0
        ljmp    $8, $3f

        hlt

        .align  4, 0xFF
gdt:
        .word   gdtEnd - gdtStart
        .long   gdtStart

        .align  4, 0xFF
idt:
        .extern idtStart
        .word   0x07FF          # space for 256 entries
        .long   idtStart

gdtStart:
        /* Selector 0x00 == invalid. */
        .word   0x0000
        .word   0x0000
        .byte   0x00
        .byte   0x00
        .byte   0x00
        .byte   0x00

        /* Selector 0x08 == code. */
        .word   0xFFFF
        .word   0x0000
        .byte   0x00
        .byte   0x9B
        .byte   0xCF
        .byte   0x00

        /* Selector 0x10 == data. */
        .word   0xFFFF
        .word   0x0000
        .byte   0x00
        .byte   0x93
        .byte   0xCF
        .byte   0x00

        /* Selector 0x18 == shorter code: faults any code 
         * access 0xF0000000-0xFFFFFFFF.
         */
        .word   0xFFFF
        .word   0x0000
        .byte   0x00
        .byte   0x9B
        .byte   0xC7
        .byte   0x00

        /* Selector 0x20 == data; faults any access 0xF0000000-0xFFFFFFFF. */
        .word   0xFFFF
        .word   0x0000
        .byte   0x00
        .byte   0x93
        .byte   0xC7
        .byte   0x00

        .align  4, 0xFF
gdtEnd:

        .code32
3:

        movw    $0x10, %ax
        movw    %ax, %ds
        movw    %ax, %es
        movw    %ax, %fs
        movw    %ax, %gs

        /* Make our new stack point to the same place as the old one. */
        xorl    %ebx, %ebx
        movw    %ss, %bx
        shl     $4, %ebx
        addl    %esp, %ebx
        movw    %ax, %ss
        movl    %ebx, %esp
        movl    $0, %ebp

        /* Reset the flags register. */
        pushl   $0
        popfl

hal_cpu_init_end:
        nop

        .endm /* hal_cpu_init */
        
#endif /* CYG_HAL_STARTUP_FLOPPY */

#endif // CYGPKG_HAL_I386_CPU_INIT_DEFINED

##=============================================================================
## Interrupt controller support
        
#define CYGPKG_HAL_I386_INTC_INIT_DEFINED

#ifndef CYG_HAL_STARTUP_RAM
                        
        .macro  hal_intc_init
        
        # The interrupt controller is configured so that IRQ levels 0-7 trigger
        #  interrupt vector 32-39; levels 8-15 trigger 40-47.
        movb    $0x11, %al
        outb    %al, $0x20
        movb    $0x20, %al
        outb    %al, $0x21
        movb    $0x04, %al
        outb    %al, $0x21
        movb    $0x01, %al
        outb    %al, $0x21
        movb    $0xFB, %al                      /* Mask off all interrupts except 2. */
        outb    %al, $0x21

        movb    $0x11, %al
        outb    %al, $0xA0
        movb    $0x28, %al
        outb    %al, $0xA1
        movb    $0x02, %al
        outb    %al, $0xA1
        movb    $0x01, %al
        outb    %al, $0xA1
        movb    $0xFF, %al                      /* Mask off all interrupts. */
        outb    %al, $0xA1

        .endm /* hal_intc_init */

#else

        # No need to do any initialization in RAM startup
        .macro  hal_intc_init
        .endm   

#endif  
        
        .macro hal_intc_ack vector
        # Use any registers you like.
        movl    \vector, %edx
        movb    $0x20, %al
        cmpl    $0x20, %edx
        jl      8f
        cmpl    $0x28, %edx
        jl      9f
        outb    %al, $0xA0
9:      outb    %al, $0x20
8:      nop
        .endm
        
##=============================================================================
#endif // ifndef CYGONCE_HAL_PCMB_INC   
## end of pcmb.inc