/* ----------------------------------------------------------------------- *
*
* 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 <stdint.h>
#include <com32.h>
#include <string.h>
#include <memory.h>
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 */
void *bounce;
com32sys_t ireg, oreg;
memset(&ireg, 0, sizeof ireg);
bounce = lmalloc(sizeof buf);
if (!bounce)
goto out;
ireg.eax.w[0] = 0xe820;
ireg.edx.l = SMAP;
ireg.ecx.l = sizeof(struct e820_ext_entry);
ireg.edi.w[0] = OFFS(bounce);
ireg.es = SEG(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(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, 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);
out:
lfree(bounce);
*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 <current_addr> > <last_addr>, swap */
/* or, if current=<start_addr> & last=<end_addr>, 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;
}