diff options
Diffstat (limited to 'memdisk/msetup.c')
| -rw-r--r-- | memdisk/msetup.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/memdisk/msetup.c b/memdisk/msetup.c new file mode 100644 index 00000000..c37169be --- /dev/null +++ b/memdisk/msetup.c @@ -0,0 +1,183 @@ +#ident "$Id$" +/* ----------------------------------------------------------------------- * + * + * Copyright 2001 H. Peter Anvin - All Rights Reserved + * + * 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 + * the Free Software Foundation, Inc., 53 Temple Place Ste 330, + * Bostom MA 02111-1307, USA; either version 2 of the License, or + * (at your option) any later version; incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +/* + * msetup.c + * + * Initialization code for memory-based disk + */ + +#include <stdint.h> +#include "e820.h" + +static inline int get_e820(void) +{ + struct e820_info { + uint64_t base; + uint64_t len; + uint32_t type; + } __attribute__((packed)); + struct e820_info buf; + uint32_t lastptr = 0; + int copied; + int range_count; + + do { + asm volatile("int $0x15 ; " + "jc 1f ; " + "cmpl $0x534d4150, %%eax ; " + "je 2f\n" + "1:\n\t" + "xorl %%ecx, %%ecx\n" + "2:" + : "=c" (copied), "=&b" (lastptr) + : "a" (0x0000e820), "d" (0x534d4150), + "c" (20), "D" (&buf) + : "esi", "ebp"); + + if ( copied < 20 ) + break; + + insertrange(buf.base, buf.len, buf.type); + range_count++; + + } while ( lastptr ); + + return !range_count; +} + +static inline void get_dos_mem(void) +{ + uint16_t dos_kb; + + asm volatile("int $0x12" : "=a" (dos_kb) + :: "ebx", "ecx", "edx", "esi", "edi", "ebp"); + + insertrange(0, (uint64_t)((uint32_t)dos_kb << 10), 1); +} + +static inline int get_e881(void) +{ + uint32_t low_mem; + uint32_t high_mem; + uint8_t err; + + asm volatile("movw $0xe881, %%ax ; " + "int $0x15 ; " + "setc %2" + : "=a" (low_mem), "=b" (high_mem), "=d" (err) + :: "ecx", "esi", "edi", "ebp"); + + if ( !err ) { + if ( low_mem ) { + insertrange(0x100000, (uint64_t)low_mem << 10, 1); + } + if ( high_mem ) { + insertrange(0x1000000, (uint64_t)high_mem << 16, 1); + } + } + + return err; +} + +static inline int get_e801(void) +{ + uint16_t low_mem; + uint16_t high_mem; + uint8_t err; + + asm volatile("movw $0xe801, %%ax ; " + "int $0x15 ; " + "setc %2" + : "=a" (low_mem), "=b" (high_mem), "=d" (err) + :: "ecx", "esi", "edi", "ebp"); + + if ( !err ) { + if ( low_mem ) { + insertrange(0x100000, (uint64_t)((uint32_t)low_mem << 10), 1); + } + if ( high_mem ) { + insertrange(0x1000000, (uint64_t)((uint32_t)high_mem << 16), 1); + } + } + + return err; +} + +static inline int get_88(void) +{ + uint16_t low_mem; + uint8_t err; + + asm volatile("movb $0x88,%%ah ; " + "int $0x15 ; " + "setc %1" + : "=a" (low_mem), "=d" (err) + :: "ebx", "ecx", "esi", "edi", "ebp"); + + if ( !err ) { + if ( low_mem ) { + insertrange(0x100000, (uint64_t)((uint32_t)low_mem << 10), 1); + } + } + + return err; +} + +uint32_t dos_mem = 0; /* 0-1MB */ +uint32_t low_mem = 0; /* 1-16MB */ +uint32_t high_mem = 0; /* 16+ MB */ + +void get_mem(void) +{ + if ( get_e820() ) { + get_dos_mem(); + if ( get_e881() ) { + if ( get_e801() ) { + if ( get_88() ) { + /* Running out of ideas here... */ + } + } + } + } +} + +void parse_mem(void) +{ + struct e820range *ep; + + /* Derive "dos mem", "high mem", and "low mem" from the range array */ + for ( ep = ranges ; ep->type != -1 ; ep++ ) { + if ( ep->type == 1 ) { + /* Only look at memory ranges */ + if ( ep->start == 0 ) { + if ( ep[1].start > 0x100000 ) + dos_mem = 0x100000; + else + dos_mem = ep[1].start; + } + if ( ep->start <= 0x100000 && ep[1].start > 0x100000 ) { + if ( ep[1].start > 0x1000000 ) + low_mem = 0x1000000 - ep->start; + else + low_mem = ep[1].start - ep->start; + } + if ( ep->start <= 0x1000000 && ep[1].start > 0x1000000 ) { + if ( ep[1].start > 0x100000000 ) + high_mem = 0x100000000 - ep->start; + else + high_mem = ep[1].start - ep->start; + } + } + } +} |