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Annotation of Gnu-Mach/i386/pc/i16/i16_ext_mem.c, revision 1.1

1.1     ! root        1: /* 
        !             2:  * Copyright (c) 1995-1994 The University of Utah and
        !             3:  * the Computer Systems Laboratory at the University of Utah (CSL).
        !             4:  * All rights reserved.
        !             5:  *
        !             6:  * Permission to use, copy, modify and distribute this software is hereby
        !             7:  * granted provided that (1) source code retains these copyright, permission,
        !             8:  * and disclaimer notices, and (2) redistributions including binaries
        !             9:  * reproduce the notices in supporting documentation, and (3) all advertising
        !            10:  * materials mentioning features or use of this software display the following
        !            11:  * acknowledgement: ``This product includes software developed by the
        !            12:  * Computer Systems Laboratory at the University of Utah.''
        !            13:  *
        !            14:  * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
        !            15:  * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
        !            16:  * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
        !            17:  *
        !            18:  * CSL requests users of this software to return to [email protected] any
        !            19:  * improvements that they make and grant CSL redistribution rights.
        !            20:  *
        !            21:  *      Author: Bryan Ford, University of Utah CSL
        !            22:  */
        !            23: 
        !            24: #include <mach/machine/code16.h>
        !            25: #include <mach/machine/vm_types.h>
        !            26: #include <mach/machine/far_ptr.h>
        !            27: #include <mach/machine/proc_reg.h>
        !            28: 
        !            29: #include "i16_bios.h"
        !            30: #include "phys_mem.h"
        !            31: #include "vm_param.h"
        !            32: #include "debug.h"
        !            33: 
        !            34: 
        !            35: static vm_offset_t ext_mem_phys_free_mem;
        !            36: static vm_size_t ext_mem_phys_free_size;
        !            37: 
        !            38: 
        !            39: CODE32
        !            40: 
        !            41: int ext_mem_collect(void)
        !            42: {
        !            43:        if (ext_mem_phys_free_mem)
        !            44:        {
        !            45:                phys_mem_add(ext_mem_phys_free_mem, ext_mem_phys_free_size);
        !            46:                ext_mem_phys_free_mem = 0;
        !            47:        }
        !            48: }
        !            49: 
        !            50: CODE16
        !            51: 
        !            52: void i16_ext_mem_check()
        !            53: {
        !            54:        vm_offset_t ext_mem_top, ext_mem_bot;
        !            55:        unsigned short ext_mem_k;
        !            56: 
        !            57:        /* Find the top of available extended memory.  */
        !            58:        asm volatile("
        !            59:                int     $0x15
        !            60:                jnc     1f
        !            61:                xorw    %%ax,%%ax
        !            62:        1:
        !            63:        " : "=a" (ext_mem_k)
        !            64:          : "a" (0x8800));
        !            65:        ext_mem_top = 0x100000 + (vm_offset_t)ext_mem_k * 1024;
        !            66: 
        !            67:        /* XXX check for >16MB memory using function 0xc7 */
        !            68: 
        !            69:        ext_mem_bot = 0x100000;
        !            70: 
        !            71:        /* Check for extended memory allocated bottom-up: method 1.
        !            72:           This uses the technique (and, loosely, the code)
        !            73:           described in the VCPI spec, version 1.0.  */
        !            74:        if (ext_mem_top > ext_mem_bot)
        !            75:        {
        !            76:                asm volatile("
        !            77:                        pushw   %%es
        !            78: 
        !            79:                        xorw    %%ax,%%ax
        !            80:                        movw    %%ax,%%es
        !            81:                        movw    %%es:0x19*4+2,%%ax
        !            82:                        movw    %%ax,%%es
        !            83: 
        !            84:                        movw    $0x12,%%di
        !            85:                        movw    $7,%%cx
        !            86:                        rep
        !            87:                        cmpsb
        !            88:                        jne     1f
        !            89: 
        !            90:                        xorl    %%edx,%%edx
        !            91:                        movb    %%es:0x2e,%%dl
        !            92:                        shll    $16,%%edx
        !            93:                        movw    %%es:0x2c,%%dx
        !            94: 
        !            95:                1:
        !            96:                        popw    %%es
        !            97:                " : "=d" (ext_mem_bot)
        !            98:                  : "d" (ext_mem_bot),
        !            99:                    "S" ((unsigned short)(vm_offset_t)"VDISK V")
        !           100:                  : "eax", "ecx", "esi", "edi");
        !           101:        }
        !           102:        i16_assert(ext_mem_bot >= 0x100000);
        !           103: 
        !           104:        /* Check for extended memory allocated bottom-up: method 2.
        !           105:           This uses the technique (and, loosely, the code)
        !           106:           described in the VCPI spec, version 1.0.  */
        !           107:        if (ext_mem_top > ext_mem_bot)
        !           108:        {
        !           109:                struct {
        !           110:                        char pad1[3];
        !           111:                        char V;
        !           112:                        long DISK;
        !           113:                        char pad2[30-8];
        !           114:                        unsigned short addr;
        !           115:                } buf;
        !           116:                unsigned char rc;
        !           117: 
        !           118:                i16_assert(sizeof(buf) == 0x20);
        !           119:                rc = i16_bios_copy_ext_mem(0x100000, kvtolin((vm_offset_t)&buf), sizeof(buf)/2);
        !           120:                if ((rc == 0) && (buf.V == 'V') && (buf.DISK == 'DISK'))
        !           121:                {
        !           122:                        vm_offset_t new_bot = (vm_offset_t)buf.addr << 10;
        !           123:                        i16_assert(new_bot > 0x100000);
        !           124:                        if (new_bot > ext_mem_bot)
        !           125:                                ext_mem_bot = new_bot;
        !           126:                }
        !           127:        }
        !           128:        i16_assert(ext_mem_bot >= 0x100000);
        !           129: 
        !           130:        if (ext_mem_top > ext_mem_bot)
        !           131:        {
        !           132:                ext_mem_phys_free_mem = ext_mem_bot;
        !           133:                ext_mem_phys_free_size = ext_mem_top - ext_mem_bot;
        !           134: 
        !           135:                /* We need to update phys_mem_max here
        !           136:                   instead of just letting phys_mem_add() do it
        !           137:                   when the memory is collected with phys_mem_collect(),
        !           138:                   because VCPI initialization needs to know the top of physical memory
        !           139:                   before phys_mem_collect() is called.
        !           140:                   See i16_vcpi.c for the gross details.  */
        !           141:                if (ext_mem_top > phys_mem_max)
        !           142:                        phys_mem_max = ext_mem_top;
        !           143:        }
        !           144: }
        !           145: 
        !           146: void i16_ext_mem_shutdown()
        !           147: {
        !           148:        /* We didn't actually allocate the memory,
        !           149:           so no need to deallocate it... */
        !           150: }
        !           151: 

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