/* ----------------------------------------------------------------------- * * * Copyright 2009 Pierre-Alexandre Meyer * * Some parts borrowed from meminfo.c32: * * Copyright 2003-2009 H. Peter Anvin - All Rights Reserved * Copyright 2009 Intel Corporation; author: H. Peter Anvin * * Some parts borrowed from Linux: * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright 2007 rPath, Inc. - All Rights Reserved * Copyright 2009 Intel Corporation; author H. Peter Anvin * * Interrupt list from Ralf Brown (http://www.cs.cmu.edu/~ralf/files.html) * * This file is part of Syslinux, and is made available under * the terms of the GNU General Public License version 2. * * ----------------------------------------------------------------------- */ #include #include #include #include const char *const e820_types[] = { "usable", "reserved", "ACPI reclaim", "ACPI NVS", "unusable", }; struct e820_ext_entry { struct e820entry std; uint32_t ext_flags; } __attribute__ ((packed)); #define SMAP 0x534d4150 /* ASCII "SMAP" */ void get_type(int type, char *type_ptr, int type_ptr_sz) { unsigned int real_type = type - 1; if (real_type < sizeof(e820_types) / sizeof(e820_types[0])) strlcpy(type_ptr, e820_types[real_type], type_ptr_sz); } /** *INT 15 - newer BIOSes - GET SYSTEM MEMORY MAP * AX = E820h * EAX = 0000E820h * EDX = 534D4150h ('SMAP') * EBX = continuation value or 00000000h to start at beginning of map * ECX = size of buffer for result, in bytes (should be >= 20 bytes) * ES:DI -> buffer for result (see #00581) * * Return: CF clear if successful * EAX = 534D4150h ('SMAP') * ES:DI buffer filled * EBX = next offset from which to copy or 00000000h if all done * ECX = actual length returned in bytes * CF set on error * AH = error code (86h) (see #00496 at INT 15/AH=80h) * * Notes: originally introduced with the Phoenix BIOS v4.0, this function is * now supported by most newer BIOSes, since various versions of Windows * call it to find out about the system memory * a maximum of 20 bytes will be transferred at one time, even if ECX is * higher; some BIOSes (e.g. Award Modular BIOS v4.50PG) ignore the * value of ECX on entry, and always copy 20 bytes * some BIOSes expect the high word of EAX to be clear on entry, i.e. * EAX=0000E820h * if this function is not supported, an application should fall back * to AX=E802h, AX=E801h, and then AH=88h * the BIOS is permitted to return a nonzero continuation value in EBX * and indicate that the end of the list has already been reached by * returning with CF set on the next iteration * this function will return base memory and ISA/PCI memory contiguous * with base memory as normal memory ranges; it will indicate * chipset-defined address holes which are not in use and motherboard * memory-mapped devices, and all occurrences of the system BIOS as * reserved; standard PC address ranges will not be reported **/ void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found) { int count = 0; static struct e820_ext_entry buf; /* static so it is zeroed */ com32sys_t ireg, oreg; memset(&ireg, 0, sizeof ireg); ireg.eax.w[0] = 0xe820; ireg.edx.l = SMAP; ireg.ecx.l = sizeof(struct e820_ext_entry); ireg.edi.w[0] = OFFS(__com32.cs_bounce); ireg.es = SEG(__com32.cs_bounce); /* * Set this here so that if the BIOS doesn't change this field * but still doesn't change %ecx, we're still okay... */ memset(&buf, 0, sizeof buf); buf.ext_flags = 1; do { memcpy(__com32.cs_bounce, &buf, sizeof buf); /* Important: %edx and %esi are clobbered by some BIOSes, so they must be either used for the error output or explicitly marked clobbered. Given that, assume there is something out there clobbering %ebp and %edi, too. */ __intcall(0x15, &ireg, &oreg); /* Some BIOSes stop returning SMAP in the middle of the search loop. We don't know exactly how the BIOS screwed up the map at that point, we might have a partial map, the full map, or complete garbage, so just return failure. */ if (oreg.eax.l != SMAP) { count = 0; break; } if (oreg.eflags.l & EFLAGS_CF || oreg.ecx.l < 20) break; memcpy(&buf, __com32.cs_bounce, sizeof buf); /* * ACPI 3.0 added the extended flags support. If bit 0 * in the extended flags is zero, we're supposed to simply * ignore the entry -- a backwards incompatible change! */ if (oreg.ecx.l > 20 && !(buf.ext_flags & 1)) continue; memcpy(&desc[count], &buf, sizeof buf); count++; /* Set continuation value */ ireg.ebx.l = oreg.ebx.l; } while (ireg.ebx.l && count < size_map); *size_found = count; } /** * detect_memory_e801 * *INT 15 - Phoenix BIOS v4.0 - GET MEMORY SIZE FOR >64M CONFIGURATIONS * AX = E801h * * Return: CF clear if successful * AX = extended memory between 1M and 16M, in K (max 3C00h = 15MB) * BX = extended memory above 16M, in 64K blocks * CX = configured memory 1M to 16M, in K * DX = configured memory above 16M, in 64K blocks * CF set on error * * Notes: supported by the A03 level (6/14/94) and later XPS P90 BIOSes, as well * as the Compaq Contura, 3/8/93 DESKPRO/i, and 7/26/93 LTE Lite 386 ROM * BIOS * supported by AMI BIOSes dated 8/23/94 or later * on some systems, the BIOS returns AX=BX=0000h; in this case, use CX * and DX instead of AX and BX * this interface is used by Windows NT 3.1, OS/2 v2.11/2.20, and is * used as a fall-back by newer versions if AX=E820h is not supported * this function is not used by MS-DOS 6.0 HIMEM.SYS when an EISA machine * (for example with parameter /EISA) (see also MEM F000h:FFD9h), or no * Compaq machine was detected, or parameter /NOABOVE16 was given. **/ int detect_memory_e801(int *mem_size_below_16, int *mem_size_above_16) { com32sys_t ireg, oreg; memset(&ireg, 0, sizeof ireg); ireg.eax.w[0] = 0xe801; __intcall(0x15, &ireg, &oreg); if (oreg.eflags.l & EFLAGS_CF) return -1; if (oreg.eax.w[0] > 0x3c00) return -1; /* Bogus! */ /* Linux seems to use ecx and edx by default if they are defined */ if (oreg.eax.w[0] || oreg.eax.w[0]) { oreg.eax.w[0] = oreg.ecx.w[0]; oreg.ebx.w[0] = oreg.edx.w[0]; } *mem_size_below_16 = oreg.eax.w[0]; /* 1K blocks */ *mem_size_above_16 = oreg.ebx.w[0]; /* 64K blocks */ return 0; } int detect_memory_88(int *mem_size) { com32sys_t ireg, oreg; memset(&ireg, 0, sizeof ireg); ireg.eax.w[0] = 0x8800; __intcall(0x15, &ireg, &oreg); if (oreg.eflags.l & EFLAGS_CF) return -1; *mem_size = oreg.eax.w[0]; return 0; } /* * Sanitize the BIOS e820 map. * * This code come from the memtest86 project. It have been adjusted to match * the syslinux environement. * Some e820 responses include overlapping entries. The following * replaces the original e820 map with a new one, removing overlaps. * * The following stuff could be merge once the addr_t will be set to 64bits. * syslinux_scan_memory can be used for that purpose */ int sanitize_e820_map(struct e820entry *orig_map, struct e820entry *new_bios, short old_nr) { struct change_member { struct e820entry *pbios; /* pointer to original bios entry */ unsigned long long addr; /* address for this change point */ }; struct change_member change_point_list[2 * E820MAX]; struct change_member *change_point[2 * E820MAX]; struct e820entry *overlap_list[E820MAX]; struct e820entry biosmap[E820MAX]; struct change_member *change_tmp; unsigned long current_type, last_type; unsigned long long last_addr; int chgidx, still_changing; int overlap_entries; int new_bios_entry; int i; /* Visually we're performing the following (1,2,3,4 = memory types)... Sample memory map (w/overlaps): ____22__________________ ______________________4_ ____1111________________ _44_____________________ 11111111________________ ____________________33__ ___________44___________ __________33333_________ ______________22________ ___________________2222_ _________111111111______ _____________________11_ _________________4______ Sanitized equivalent (no overlap): 1_______________________ _44_____________________ ___1____________________ ____22__________________ ______11________________ _________1______________ __________3_____________ ___________44___________ _____________33_________ _______________2________ ________________1_______ _________________4______ ___________________2____ ____________________33__ ______________________4_ */ /* First make a copy of the map */ for (i = 0; i < old_nr; i++) { biosmap[i].addr = orig_map[i].addr; biosmap[i].size = orig_map[i].size; biosmap[i].type = orig_map[i].type; } /* bail out if we find any unreasonable addresses in bios map */ for (i = 0; i < old_nr; i++) { if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr) return 0; } /* create pointers for initial change-point information (for sorting) */ for (i = 0; i < 2 * old_nr; i++) change_point[i] = &change_point_list[i]; /* record all known change-points (starting and ending addresses) */ chgidx = 0; for (i = 0; i < old_nr; i++) { change_point[chgidx]->addr = biosmap[i].addr; change_point[chgidx++]->pbios = &biosmap[i]; change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size; change_point[chgidx++]->pbios = &biosmap[i]; } /* sort change-point list by memory addresses (low -> high) */ still_changing = 1; while (still_changing) { still_changing = 0; for (i = 1; i < 2 * old_nr; i++) { /* if > , swap */ /* or, if current= & last=, swap */ if ((change_point[i]->addr < change_point[i - 1]->addr) || ((change_point[i]->addr == change_point[i - 1]->addr) && (change_point[i]->addr == change_point[i]->pbios->addr) && (change_point[i - 1]->addr != change_point[i - 1]->pbios->addr)) ) { change_tmp = change_point[i]; change_point[i] = change_point[i - 1]; change_point[i - 1] = change_tmp; still_changing = 1; } } } /* create a new bios memory map, removing overlaps */ overlap_entries = 0; /* number of entries in the overlap table */ new_bios_entry = 0; /* index for creating new bios map entries */ last_type = 0; /* start with undefined memory type */ last_addr = 0; /* start with 0 as last starting address */ /* loop through change-points, determining affect on the new bios map */ for (chgidx = 0; chgidx < 2 * old_nr; chgidx++) { /* keep track of all overlapping bios entries */ if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr) { /* add map entry to overlap list (> 1 entry implies an overlap) */ overlap_list[overlap_entries++] = change_point[chgidx]->pbios; } else { /* remove entry from list (order independent, so swap with last) */ for (i = 0; i < overlap_entries; i++) { if (overlap_list[i] == change_point[chgidx]->pbios) overlap_list[i] = overlap_list[overlap_entries - 1]; } overlap_entries--; } /* if there are overlapping entries, decide which "type" to use */ /* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */ current_type = 0; for (i = 0; i < overlap_entries; i++) if (overlap_list[i]->type > current_type) current_type = overlap_list[i]->type; /* continue building up new bios map based on this information */ if (current_type != last_type) { if (last_type != 0) { new_bios[new_bios_entry].size = change_point[chgidx]->addr - last_addr; /* move forward only if the new size was non-zero */ if (new_bios[new_bios_entry].size != 0) if (++new_bios_entry >= E820MAX) break; /* no more space left for new bios entries */ } if (current_type != 0) { new_bios[new_bios_entry].addr = change_point[chgidx]->addr; new_bios[new_bios_entry].type = current_type; last_addr = change_point[chgidx]->addr; } last_type = current_type; } } return (new_bios_entry); } /* The following stuff could be merge once the addr_t will be set to 64bits. * syslinux_scan_memory can be used for that purpose */ unsigned long detect_memsize(void) { unsigned long memory_size = 0; /* Try to detect memory via e820 */ struct e820entry map[E820MAX]; int count = 0; detect_memory_e820(map, E820MAX, &count); memory_size = memsize_e820(map, count); if (memory_size > 0) return memory_size; /*e820 failed, let's try e801 */ int mem_low, mem_high = 0; if (!detect_memory_e801(&mem_low, &mem_high)) return mem_low + (mem_high << 6); /*e801 failed, let's try e88 */ int mem_size = 0; if (!detect_memory_88(&mem_size)) return mem_size; /* We were enable to detect any kind of memory */ return 0; } /* The following stuff could be merge once the addr_t will be set to 64bits. * syslinux_scan_memory can be used for that purpose */ unsigned long memsize_e820(struct e820entry *e820, int e820_nr) { int i, n, nr; unsigned long memory_size = 0; struct e820entry nm[E820MAX]; /* Clean up, adjust and copy the BIOS-supplied E820-map. */ nr = sanitize_e820_map(e820, nm, e820_nr); /* If there is not a good 820 map returning 0 to indicate that we don't have any idea of the amount of ram we have */ if (nr < 1 || nr > E820MAX) { return 0; } /* Build the memory map for testing */ n = 0; for (i = 0; i < nr; i++) { if (nm[i].type == E820_RAM || nm[i].type == E820_ACPI) { unsigned long long start; unsigned long long end; start = nm[i].addr; end = start + nm[i].size; /* Don't ever use memory between 640 and 1024k */ if (start > RES_START && start < RES_END) { if (end < RES_END) { continue; } start = RES_END; } if (end > RES_START && end < RES_END) { end = RES_START; } memory_size += (end >> 12) - ((start + 4095) >> 12); n++; } else if (nm[i].type == E820_NVS) { memory_size += nm[i].size >> 12; } } return memory_size * 4; }