kernel-fxtec-pro1x/arch/i386/kernel/e820.c
Artiom Myaskouvskey bf7e6a1963 [PATCH] i386: Preserve EFI run time regions with memmap parameter
When using memmap kernel parameter in EFI boot we should also add to memory map
memory regions of runtime services to enable their mapping later.

AK: merged and cleaned up the patch

Signed-off-by: Artiom Myaskouvskey <artiom.myaskouvskey@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-12-07 02:14:11 +01:00

894 lines
23 KiB
C

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
#include <linux/string.h>
#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/efi.h>
#include <linux/pfn.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/e820.h>
#ifdef CONFIG_EFI
int efi_enabled = 0;
EXPORT_SYMBOL(efi_enabled);
#endif
struct e820map e820;
struct change_member {
struct e820entry *pbios; /* pointer to original bios entry */
unsigned long long addr; /* address for this change point */
};
static struct change_member change_point_list[2*E820MAX] __initdata;
static struct change_member *change_point[2*E820MAX] __initdata;
static struct e820entry *overlap_list[E820MAX] __initdata;
static struct e820entry new_bios[E820MAX] __initdata;
/* For PCI or other memory-mapped resources */
unsigned long pci_mem_start = 0x10000000;
#ifdef CONFIG_PCI
EXPORT_SYMBOL(pci_mem_start);
#endif
extern int user_defined_memmap;
struct resource data_resource = {
.name = "Kernel data",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
struct resource code_resource = {
.name = "Kernel code",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
static struct resource system_rom_resource = {
.name = "System ROM",
.start = 0xf0000,
.end = 0xfffff,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
};
static struct resource extension_rom_resource = {
.name = "Extension ROM",
.start = 0xe0000,
.end = 0xeffff,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
};
static struct resource adapter_rom_resources[] = { {
.name = "Adapter ROM",
.start = 0xc8000,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
.name = "Adapter ROM",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
.name = "Adapter ROM",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
.name = "Adapter ROM",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
.name = "Adapter ROM",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
}, {
.name = "Adapter ROM",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
} };
static struct resource video_rom_resource = {
.name = "Video ROM",
.start = 0xc0000,
.end = 0xc7fff,
.flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
};
static struct resource video_ram_resource = {
.name = "Video RAM area",
.start = 0xa0000,
.end = 0xbffff,
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
static struct resource standard_io_resources[] = { {
.name = "dma1",
.start = 0x0000,
.end = 0x001f,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "pic1",
.start = 0x0020,
.end = 0x0021,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "timer0",
.start = 0x0040,
.end = 0x0043,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "timer1",
.start = 0x0050,
.end = 0x0053,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "keyboard",
.start = 0x0060,
.end = 0x006f,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "dma page reg",
.start = 0x0080,
.end = 0x008f,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "pic2",
.start = 0x00a0,
.end = 0x00a1,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "dma2",
.start = 0x00c0,
.end = 0x00df,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
}, {
.name = "fpu",
.start = 0x00f0,
.end = 0x00ff,
.flags = IORESOURCE_BUSY | IORESOURCE_IO
} };
static int romsignature(const unsigned char *x)
{
unsigned short sig;
int ret = 0;
if (probe_kernel_address((const unsigned short *)x, sig) == 0)
ret = (sig == 0xaa55);
return ret;
}
static int __init romchecksum(unsigned char *rom, unsigned long length)
{
unsigned char *p, sum = 0;
for (p = rom; p < rom + length; p++)
sum += *p;
return sum == 0;
}
static void __init probe_roms(void)
{
unsigned long start, length, upper;
unsigned char *rom;
int i;
/* video rom */
upper = adapter_rom_resources[0].start;
for (start = video_rom_resource.start; start < upper; start += 2048) {
rom = isa_bus_to_virt(start);
if (!romsignature(rom))
continue;
video_rom_resource.start = start;
/* 0 < length <= 0x7f * 512, historically */
length = rom[2] * 512;
/* if checksum okay, trust length byte */
if (length && romchecksum(rom, length))
video_rom_resource.end = start + length - 1;
request_resource(&iomem_resource, &video_rom_resource);
break;
}
start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
if (start < upper)
start = upper;
/* system rom */
request_resource(&iomem_resource, &system_rom_resource);
upper = system_rom_resource.start;
/* check for extension rom (ignore length byte!) */
rom = isa_bus_to_virt(extension_rom_resource.start);
if (romsignature(rom)) {
length = extension_rom_resource.end - extension_rom_resource.start + 1;
if (romchecksum(rom, length)) {
request_resource(&iomem_resource, &extension_rom_resource);
upper = extension_rom_resource.start;
}
}
/* check for adapter roms on 2k boundaries */
for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
rom = isa_bus_to_virt(start);
if (!romsignature(rom))
continue;
/* 0 < length <= 0x7f * 512, historically */
length = rom[2] * 512;
/* but accept any length that fits if checksum okay */
if (!length || start + length > upper || !romchecksum(rom, length))
continue;
adapter_rom_resources[i].start = start;
adapter_rom_resources[i].end = start + length - 1;
request_resource(&iomem_resource, &adapter_rom_resources[i]);
start = adapter_rom_resources[i++].end & ~2047UL;
}
}
/*
* Request address space for all standard RAM and ROM resources
* and also for regions reported as reserved by the e820.
*/
static void __init
legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
{
int i;
probe_roms();
for (i = 0; i < e820.nr_map; i++) {
struct resource *res;
#ifndef CONFIG_RESOURCES_64BIT
if (e820.map[i].addr + e820.map[i].size > 0x100000000ULL)
continue;
#endif
res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
switch (e820.map[i].type) {
case E820_RAM: res->name = "System RAM"; break;
case E820_ACPI: res->name = "ACPI Tables"; break;
case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
default: res->name = "reserved";
}
res->start = e820.map[i].addr;
res->end = res->start + e820.map[i].size - 1;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
if (request_resource(&iomem_resource, res)) {
kfree(res);
continue;
}
if (e820.map[i].type == E820_RAM) {
/*
* We don't know which RAM region contains kernel data,
* so we try it repeatedly and let the resource manager
* test it.
*/
request_resource(res, code_resource);
request_resource(res, data_resource);
#ifdef CONFIG_KEXEC
request_resource(res, &crashk_res);
#endif
}
}
}
/*
* Request address space for all standard resources
*
* This is called just before pcibios_init(), which is also a
* subsys_initcall, but is linked in later (in arch/i386/pci/common.c).
*/
static int __init request_standard_resources(void)
{
int i;
printk("Setting up standard PCI resources\n");
if (efi_enabled)
efi_initialize_iomem_resources(&code_resource, &data_resource);
else
legacy_init_iomem_resources(&code_resource, &data_resource);
/* EFI systems may still have VGA */
request_resource(&iomem_resource, &video_ram_resource);
/* request I/O space for devices used on all i[345]86 PCs */
for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
request_resource(&ioport_resource, &standard_io_resources[i]);
return 0;
}
subsys_initcall(request_standard_resources);
void __init add_memory_region(unsigned long long start,
unsigned long long size, int type)
{
int x;
if (!efi_enabled) {
x = e820.nr_map;
if (x == E820MAX) {
printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
return;
}
e820.map[x].addr = start;
e820.map[x].size = size;
e820.map[x].type = type;
e820.nr_map++;
}
} /* add_memory_region */
/*
* Sanitize the BIOS e820 map.
*
* Some e820 responses include overlapping entries. The following
* replaces the original e820 map with a new one, removing overlaps.
*
*/
int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
{
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 old_nr, new_nr, chg_nr;
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_
*/
printk("sanitize start\n");
/* if there's only one memory region, don't bother */
if (*pnr_map < 2) {
printk("sanitize bail 0\n");
return -1;
}
old_nr = *pnr_map;
/* 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) {
printk("sanitize bail 1\n");
return -1;
}
/* 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),
omitting those that are for empty memory regions */
chgidx = 0;
for (i=0; i < old_nr; i++) {
if (biosmap[i].size != 0) {
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];
}
}
chg_nr = chgidx; /* true number of change-points */
/* sort change-point list by memory addresses (low -> high) */
still_changing = 1;
while (still_changing) {
still_changing = 0;
for (i=1; i < chg_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 < chg_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;
}
}
new_nr = new_bios_entry; /* retain count for new bios entries */
/* copy new bios mapping into original location */
memcpy(biosmap, new_bios, new_nr*sizeof(struct e820entry));
*pnr_map = new_nr;
printk("sanitize end\n");
return 0;
}
/*
* Copy the BIOS e820 map into a safe place.
*
* Sanity-check it while we're at it..
*
* If we're lucky and live on a modern system, the setup code
* will have given us a memory map that we can use to properly
* set up memory. If we aren't, we'll fake a memory map.
*
* We check to see that the memory map contains at least 2 elements
* before we'll use it, because the detection code in setup.S may
* not be perfect and most every PC known to man has two memory
* regions: one from 0 to 640k, and one from 1mb up. (The IBM
* thinkpad 560x, for example, does not cooperate with the memory
* detection code.)
*/
int __init copy_e820_map(struct e820entry * biosmap, int nr_map)
{
/* Only one memory region (or negative)? Ignore it */
if (nr_map < 2)
return -1;
do {
unsigned long long start = biosmap->addr;
unsigned long long size = biosmap->size;
unsigned long long end = start + size;
unsigned long type = biosmap->type;
printk("copy_e820_map() start: %016Lx size: %016Lx end: %016Lx type: %ld\n", start, size, end, type);
/* Overflow in 64 bits? Ignore the memory map. */
if (start > end)
return -1;
/*
* Some BIOSes claim RAM in the 640k - 1M region.
* Not right. Fix it up.
*/
if (type == E820_RAM) {
printk("copy_e820_map() type is E820_RAM\n");
if (start < 0x100000ULL && end > 0xA0000ULL) {
printk("copy_e820_map() lies in range...\n");
if (start < 0xA0000ULL) {
printk("copy_e820_map() start < 0xA0000ULL\n");
add_memory_region(start, 0xA0000ULL-start, type);
}
if (end <= 0x100000ULL) {
printk("copy_e820_map() end <= 0x100000ULL\n");
continue;
}
start = 0x100000ULL;
size = end - start;
}
}
add_memory_region(start, size, type);
} while (biosmap++,--nr_map);
return 0;
}
/*
* Callback for efi_memory_walk.
*/
static int __init
efi_find_max_pfn(unsigned long start, unsigned long end, void *arg)
{
unsigned long *max_pfn = arg, pfn;
if (start < end) {
pfn = PFN_UP(end -1);
if (pfn > *max_pfn)
*max_pfn = pfn;
}
return 0;
}
static int __init
efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
{
memory_present(0, PFN_UP(start), PFN_DOWN(end));
return 0;
}
/*
* Find the highest page frame number we have available
*/
void __init find_max_pfn(void)
{
int i;
max_pfn = 0;
if (efi_enabled) {
efi_memmap_walk(efi_find_max_pfn, &max_pfn);
efi_memmap_walk(efi_memory_present_wrapper, NULL);
return;
}
for (i = 0; i < e820.nr_map; i++) {
unsigned long start, end;
/* RAM? */
if (e820.map[i].type != E820_RAM)
continue;
start = PFN_UP(e820.map[i].addr);
end = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
if (start >= end)
continue;
if (end > max_pfn)
max_pfn = end;
memory_present(0, start, end);
}
}
/*
* Free all available memory for boot time allocation. Used
* as a callback function by efi_memory_walk()
*/
static int __init
free_available_memory(unsigned long start, unsigned long end, void *arg)
{
/* check max_low_pfn */
if (start >= (max_low_pfn << PAGE_SHIFT))
return 0;
if (end >= (max_low_pfn << PAGE_SHIFT))
end = max_low_pfn << PAGE_SHIFT;
if (start < end)
free_bootmem(start, end - start);
return 0;
}
/*
* Register fully available low RAM pages with the bootmem allocator.
*/
void __init register_bootmem_low_pages(unsigned long max_low_pfn)
{
int i;
if (efi_enabled) {
efi_memmap_walk(free_available_memory, NULL);
return;
}
for (i = 0; i < e820.nr_map; i++) {
unsigned long curr_pfn, last_pfn, size;
/*
* Reserve usable low memory
*/
if (e820.map[i].type != E820_RAM)
continue;
/*
* We are rounding up the start address of usable memory:
*/
curr_pfn = PFN_UP(e820.map[i].addr);
if (curr_pfn >= max_low_pfn)
continue;
/*
* ... and at the end of the usable range downwards:
*/
last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
if (last_pfn > max_low_pfn)
last_pfn = max_low_pfn;
/*
* .. finally, did all the rounding and playing
* around just make the area go away?
*/
if (last_pfn <= curr_pfn)
continue;
size = last_pfn - curr_pfn;
free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
}
}
void __init register_memory(void)
{
unsigned long gapstart, gapsize, round;
unsigned long long last;
int i;
/*
* Search for the bigest gap in the low 32 bits of the e820
* memory space.
*/
last = 0x100000000ull;
gapstart = 0x10000000;
gapsize = 0x400000;
i = e820.nr_map;
while (--i >= 0) {
unsigned long long start = e820.map[i].addr;
unsigned long long end = start + e820.map[i].size;
/*
* Since "last" is at most 4GB, we know we'll
* fit in 32 bits if this condition is true
*/
if (last > end) {
unsigned long gap = last - end;
if (gap > gapsize) {
gapsize = gap;
gapstart = end;
}
}
if (start < last)
last = start;
}
/*
* See how much we want to round up: start off with
* rounding to the next 1MB area.
*/
round = 0x100000;
while ((gapsize >> 4) > round)
round += round;
/* Fun with two's complement */
pci_mem_start = (gapstart + round) & -round;
printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
pci_mem_start, gapstart, gapsize);
}
void __init print_memory_map(char *who)
{
int i;
for (i = 0; i < e820.nr_map; i++) {
printk(" %s: %016Lx - %016Lx ", who,
e820.map[i].addr,
e820.map[i].addr + e820.map[i].size);
switch (e820.map[i].type) {
case E820_RAM: printk("(usable)\n");
break;
case E820_RESERVED:
printk("(reserved)\n");
break;
case E820_ACPI:
printk("(ACPI data)\n");
break;
case E820_NVS:
printk("(ACPI NVS)\n");
break;
default: printk("type %lu\n", e820.map[i].type);
break;
}
}
}
static __init __always_inline void efi_limit_regions(unsigned long long size)
{
unsigned long long current_addr = 0;
efi_memory_desc_t *md, *next_md;
void *p, *p1;
int i, j;
j = 0;
p1 = memmap.map;
for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
md = p;
next_md = p1;
current_addr = md->phys_addr +
PFN_PHYS(md->num_pages);
if (is_available_memory(md)) {
if (md->phys_addr >= size) continue;
memcpy(next_md, md, memmap.desc_size);
if (current_addr >= size) {
next_md->num_pages -=
PFN_UP(current_addr-size);
}
p1 += memmap.desc_size;
next_md = p1;
j++;
} else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
EFI_MEMORY_RUNTIME) {
/* In order to make runtime services
* available we have to include runtime
* memory regions in memory map */
memcpy(next_md, md, memmap.desc_size);
p1 += memmap.desc_size;
next_md = p1;
j++;
}
}
memmap.nr_map = j;
memmap.map_end = memmap.map +
(memmap.nr_map * memmap.desc_size);
}
void __init limit_regions(unsigned long long size)
{
unsigned long long current_addr;
int i;
print_memory_map("limit_regions start");
if (efi_enabled) {
efi_limit_regions(size);
return;
}
for (i = 0; i < e820.nr_map; i++) {
current_addr = e820.map[i].addr + e820.map[i].size;
if (current_addr < size)
continue;
if (e820.map[i].type != E820_RAM)
continue;
if (e820.map[i].addr >= size) {
/*
* This region starts past the end of the
* requested size, skip it completely.
*/
e820.nr_map = i;
} else {
e820.nr_map = i + 1;
e820.map[i].size -= current_addr - size;
}
print_memory_map("limit_regions endfor");
return;
}
print_memory_map("limit_regions endfunc");
}
/*
* This function checks if the entire range <start,end> is mapped with type.
*
* Note: this function only works correct if the e820 table is sorted and
* not-overlapping, which is the case
*/
int __init
e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
{
u64 start = s;
u64 end = e;
int i;
for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
if (type && ei->type != type)
continue;
/* is the region (part) in overlap with the current region ?*/
if (ei->addr >= end || ei->addr + ei->size <= start)
continue;
/* if the region is at the beginning of <start,end> we move
* start to the end of the region since it's ok until there
*/
if (ei->addr <= start)
start = ei->addr + ei->size;
/* if start is now at or beyond end, we're done, full
* coverage */
if (start >= end)
return 1; /* we're done */
}
return 0;
}
static int __init parse_memmap(char *arg)
{
if (!arg)
return -EINVAL;
if (strcmp(arg, "exactmap") == 0) {
#ifdef CONFIG_CRASH_DUMP
/* If we are doing a crash dump, we
* still need to know the real mem
* size before original memory map is
* reset.
*/
find_max_pfn();
saved_max_pfn = max_pfn;
#endif
e820.nr_map = 0;
user_defined_memmap = 1;
} else {
/* If the user specifies memory size, we
* limit the BIOS-provided memory map to
* that size. exactmap can be used to specify
* the exact map. mem=number can be used to
* trim the existing memory map.
*/
unsigned long long start_at, mem_size;
mem_size = memparse(arg, &arg);
if (*arg == '@') {
start_at = memparse(arg+1, &arg);
add_memory_region(start_at, mem_size, E820_RAM);
} else if (*arg == '#') {
start_at = memparse(arg+1, &arg);
add_memory_region(start_at, mem_size, E820_ACPI);
} else if (*arg == '$') {
start_at = memparse(arg+1, &arg);
add_memory_region(start_at, mem_size, E820_RESERVED);
} else {
limit_regions(mem_size);
user_defined_memmap = 1;
}
}
return 0;
}
early_param("memmap", parse_memmap);