diff options
Diffstat (limited to 'sys/boot/pc98/libpc98/biosmem.c')
| -rw-r--r-- | sys/boot/pc98/libpc98/biosmem.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/sys/boot/pc98/libpc98/biosmem.c b/sys/boot/pc98/libpc98/biosmem.c new file mode 100644 index 0000000..e2e792c --- /dev/null +++ b/sys/boot/pc98/libpc98/biosmem.c @@ -0,0 +1,115 @@ +/*- + * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * Obtain memory configuration information from the BIOS + */ +#include <stand.h> +#include "libi386.h" +#include "btxv86.h" + +vm_offset_t memtop; +u_int32_t bios_basemem, bios_extmem; + +#ifndef PC98 +#define SMAPSIG 0x534D4150 + +struct smap { + u_int64_t base; + u_int64_t length; + u_int32_t type; +} __packed; + +static struct smap smap; +#endif + +void +bios_getmem(void) +{ + +#ifdef PC98 + bios_basemem = ((*(u_char *)PTOV(0xA1501) & 0x07) + 1) * 128 * 1024; + bios_extmem = *(u_char *)PTOV(0xA1401) * 128 * 1024 + + *(u_int16_t *)PTOV(0xA1594) * 1024 * 1024; +#else + /* Parse system memory map */ + v86.ebx = 0; + do { + v86.ctl = V86_FLAGS; + v86.addr = 0x15; /* int 0x15 function 0xe820*/ + v86.eax = 0xe820; + v86.ecx = sizeof(struct smap); + v86.edx = SMAPSIG; + v86.es = VTOPSEG(&smap); + v86.edi = VTOPOFF(&smap); + v86int(); + if ((v86.efl & 1) || (v86.eax != SMAPSIG)) + break; + /* look for a low-memory segment that's large enough */ + if ((smap.type == 1) && (smap.base == 0) && (smap.length >= (512 * 1024))) + bios_basemem = smap.length; + /* look for the first segment in 'extended' memory */ + if ((smap.type == 1) && (smap.base == 0x100000)) { + bios_extmem = smap.length; + } + } while (v86.ebx != 0); + + /* Fall back to the old compatibility function for base memory */ + if (bios_basemem == 0) { + v86.ctl = 0; + v86.addr = 0x12; /* int 0x12 */ + v86int(); + + bios_basemem = (v86.eax & 0xffff) * 1024; + } + + /* Fall back through several compatibility functions for extended memory */ + if (bios_extmem == 0) { + v86.ctl = V86_FLAGS; + v86.addr = 0x15; /* int 0x15 function 0xe801*/ + v86.eax = 0xe801; + v86int(); + if (!(v86.efl & 1)) { + bios_extmem = ((v86.ecx & 0xffff) + ((v86.edx & 0xffff) * 64)) * 1024; + } + } + if (bios_extmem == 0) { + v86.ctl = 0; + v86.addr = 0x15; /* int 0x15 function 0x88*/ + v86.eax = 0x8800; + v86int(); + bios_extmem = (v86.eax & 0xffff) * 1024; + } +#endif + + /* Set memtop to actual top of memory */ + memtop = 0x100000 + bios_extmem; + +} + |
