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Diffstat (limited to 'i386/pc/i16/i16_ext_mem.c')
| -rw-r--r-- | i386/pc/i16/i16_ext_mem.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/i386/pc/i16/i16_ext_mem.c b/i386/pc/i16/i16_ext_mem.c new file mode 100644 index 0000000..08cbecf --- /dev/null +++ b/i386/pc/i16/i16_ext_mem.c @@ -0,0 +1,151 @@ +/* + * Copyright (c) 1995-1994 The University of Utah and + * the Computer Systems Laboratory at the University of Utah (CSL). + * All rights reserved. + * + * Permission to use, copy, modify and distribute this software is hereby + * granted provided that (1) source code retains these copyright, permission, + * and disclaimer notices, and (2) redistributions including binaries + * reproduce the notices in supporting documentation, and (3) all advertising + * materials mentioning features or use of this software display the following + * acknowledgement: ``This product includes software developed by the + * Computer Systems Laboratory at the University of Utah.'' + * + * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS + * IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF + * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * CSL requests users of this software to return to csl-dist@cs.utah.edu any + * improvements that they make and grant CSL redistribution rights. + * + * Author: Bryan Ford, University of Utah CSL + */ + +#include <mach/machine/code16.h> +#include <mach/machine/vm_types.h> +#include <mach/machine/far_ptr.h> +#include <mach/machine/proc_reg.h> + +#include "i16_bios.h" +#include "phys_mem.h" +#include "vm_param.h" +#include "debug.h" + + +static vm_offset_t ext_mem_phys_free_mem; +static vm_size_t ext_mem_phys_free_size; + + +CODE32 + +int ext_mem_collect(void) +{ + if (ext_mem_phys_free_mem) + { + phys_mem_add(ext_mem_phys_free_mem, ext_mem_phys_free_size); + ext_mem_phys_free_mem = 0; + } +} + +CODE16 + +void i16_ext_mem_check() +{ + vm_offset_t ext_mem_top, ext_mem_bot; + unsigned short ext_mem_k; + + /* Find the top of available extended memory. */ + asm volatile(" + int $0x15 + jnc 1f + xorw %%ax,%%ax + 1: + " : "=a" (ext_mem_k) + : "a" (0x8800)); + ext_mem_top = 0x100000 + (vm_offset_t)ext_mem_k * 1024; + + /* XXX check for >16MB memory using function 0xc7 */ + + ext_mem_bot = 0x100000; + + /* Check for extended memory allocated bottom-up: method 1. + This uses the technique (and, loosely, the code) + described in the VCPI spec, version 1.0. */ + if (ext_mem_top > ext_mem_bot) + { + asm volatile(" + pushw %%es + + xorw %%ax,%%ax + movw %%ax,%%es + movw %%es:0x19*4+2,%%ax + movw %%ax,%%es + + movw $0x12,%%di + movw $7,%%cx + rep + cmpsb + jne 1f + + xorl %%edx,%%edx + movb %%es:0x2e,%%dl + shll $16,%%edx + movw %%es:0x2c,%%dx + + 1: + popw %%es + " : "=d" (ext_mem_bot) + : "d" (ext_mem_bot), + "S" ((unsigned short)(vm_offset_t)"VDISK V") + : "eax", "ecx", "esi", "edi"); + } + i16_assert(ext_mem_bot >= 0x100000); + + /* Check for extended memory allocated bottom-up: method 2. + This uses the technique (and, loosely, the code) + described in the VCPI spec, version 1.0. */ + if (ext_mem_top > ext_mem_bot) + { + struct { + char pad1[3]; + char V; + long DISK; + char pad2[30-8]; + unsigned short addr; + } buf; + unsigned char rc; + + i16_assert(sizeof(buf) == 0x20); + rc = i16_bios_copy_ext_mem(0x100000, kvtolin((vm_offset_t)&buf), sizeof(buf)/2); + if ((rc == 0) && (buf.V == 'V') && (buf.DISK == 'DISK')) + { + vm_offset_t new_bot = (vm_offset_t)buf.addr << 10; + i16_assert(new_bot > 0x100000); + if (new_bot > ext_mem_bot) + ext_mem_bot = new_bot; + } + } + i16_assert(ext_mem_bot >= 0x100000); + + if (ext_mem_top > ext_mem_bot) + { + ext_mem_phys_free_mem = ext_mem_bot; + ext_mem_phys_free_size = ext_mem_top - ext_mem_bot; + + /* We need to update phys_mem_max here + instead of just letting phys_mem_add() do it + when the memory is collected with phys_mem_collect(), + because VCPI initialization needs to know the top of physical memory + before phys_mem_collect() is called. + See i16_vcpi.c for the gross details. */ + if (ext_mem_top > phys_mem_max) + phys_mem_max = ext_mem_top; + } +} + +void i16_ext_mem_shutdown() +{ + /* We didn't actually allocate the memory, + so no need to deallocate it... */ +} + |