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#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
#include "v86.h"
#define REAL_MEM_BLOCKS 0x100
u8 *mem_low; /* 0x000000 - 0x001000 */
u8 *mem_real; /* 0x010000 - 0x09ffff */
u8 *mem_vbios; /* 0x0c0000 - 0x0cxxxx */
u8 *mem_sbios; /* 0x0f0000 - 0x0fffff */
u8 *mem_vram; /* 0x0a0000 - 0xbfffff */
u8 *mem_ebda; /* usually: 0x9fc00 - 0x9ffff */
static u32 ebda_start;
static u32 ebda_size;
static u32 ebda_diff;
static u32 vbios_size;
struct mem_block {
unsigned int size : 20;
unsigned int free : 1;
};
static struct {
int ready;
int count;
struct mem_block blocks[REAL_MEM_BLOCKS];
} mem_info = { 0 };
void *vptr(u32 addr) {
/* Order the if's in the expected probability of access to the
* given region of memory. */
if (addr >= REAL_MEM_BASE && addr < REAL_MEM_BASE + REAL_MEM_SIZE)
return (mem_real + addr - REAL_MEM_BASE);
else if (addr >= VBIOS_BASE && addr < VBIOS_BASE + vbios_size)
return (mem_vbios + addr - VBIOS_BASE);
else if (addr >= SBIOS_BASE && addr < SBIOS_BASE + SBIOS_SIZE)
return (mem_sbios + addr - SBIOS_BASE);
else if (addr >= VRAM_BASE && addr < VRAM_BASE + VRAM_SIZE)
return (mem_vram + addr - VRAM_BASE);
else if (addr < IVTBDA_SIZE)
return (mem_low + addr);
else if (addr >= ebda_start && addr < ebda_start + ebda_size)
return (mem_ebda + addr - ebda_start + ebda_diff);
else {
ulog(LOG_WARNING, "Trying to access an unsupported memory region at %x", addr);
return NULL;
}
}
/* We don't care about memory accesses at boundaries of different memory
* regions, since our v86 memory is non contiguous anyway. */
u8 v_rdb(u32 addr) {
return *(u8*) vptr(addr);
}
u16 v_rdw(u32 addr) {
return *(u16*) vptr(addr);
}
u32 v_rdl(u32 addr) {
return *(u32*) vptr(addr);
}
void v_wrb(u32 addr, u8 val) {
u8 *t = vptr(addr);
*t = val;
}
void v_wrw(u32 addr, u16 val) {
u16 *t = vptr(addr);
*t = val;
}
void v_wrl(u32 addr, u32 val) {
u32 *t = vptr(addr);
*t = val;
}
static void *map_file(void *start, size_t length, int prot, int flags, char *name, long offset)
{
void *m;
int fd;
fd = open(name, (flags & MAP_SHARED) ? O_RDWR : O_RDONLY);
if (fd == -1) {
ulog(LOG_ERR, "Open '%s' failed with: %s\n", name, strerror(errno));
return NULL;
}
m = mmap(start, length, prot, flags, fd, offset);
if (m == (void *)-1) {
ulog(LOG_ERR, "mmap '%s' failed with: %s\n", name, strerror(errno));
close(fd);
return NULL;
}
close(fd);
return m;
}
static int real_mem_init(void)
{
if (mem_info.ready)
return 0;
mem_real = map_file(NULL, REAL_MEM_SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE, "/dev/zero", 0);
if (!mem_real)
return 1;
mem_info.ready = 1;
mem_info.count = 1;
mem_info.blocks[0].size = REAL_MEM_SIZE;
mem_info.blocks[0].free = 1;
return 0;
}
static void real_mem_deinit(void)
{
if (mem_info.ready) {
munmap(mem_real, REAL_MEM_SIZE);
mem_info.ready = 0;
}
}
static void insert_block(int i)
{
memmove(mem_info.blocks + i + 1, mem_info.blocks + i,
(mem_info.count - i) * sizeof(struct mem_block));
mem_info.count++;
}
static void delete_block(int i)
{
mem_info.count--;
memmove(mem_info.blocks + i, mem_info.blocks + i + 1,
(mem_info.count - i) * sizeof(struct mem_block));
}
u32 v86_mem_alloc(int size)
{
int i;
u32 r = REAL_MEM_BASE;
if (!mem_info.ready)
return 0;
if (mem_info.count == REAL_MEM_BLOCKS)
return 0;
size = (size + 15) & ~15;
for (i = 0; i < mem_info.count; i++) {
if (mem_info.blocks[i].free && size < mem_info.blocks[i].size) {
insert_block(i);
mem_info.blocks[i].size = size;
mem_info.blocks[i].free = 0;
mem_info.blocks[i + 1].size -= size;
return r;
}
r += mem_info.blocks[i].size;
}
return 0;
}
void v86_mem_free(u32 m)
{
int i;
u32 r = REAL_MEM_BASE;
if (!mem_info.ready)
return;
i = 0;
while (m != r) {
r += mem_info.blocks[i].size;
i++;
if (i == mem_info.count)
return;
}
mem_info.blocks[i].free = 1;
if (i + 1 < mem_info.count && mem_info.blocks[i + 1].free) {
mem_info.blocks[i].size += mem_info.blocks[i + 1].size;
delete_block(i + 1);
}
if (i - 1 >= 0 && mem_info.blocks[i - 1].free) {
mem_info.blocks[i - 1].size += mem_info.blocks[i].size;
delete_block(i);
}
}
static int get_bytes_from_phys(u32 addr, int num_bytes, void *dest)
{
u8 *mem_tmp;
int size = num_bytes;
u32 diff = 0;
u32 t;
t = addr & -getpagesize();
if (t) {
diff = addr - t;
addr = t;
size += diff;
}
mem_tmp = map_file(NULL, size, PROT_READ | PROT_WRITE,
MAP_SHARED, "/dev/mem", addr);
if (!mem_tmp)
return -1;
memcpy(dest, mem_tmp + diff, num_bytes);
munmap(mem_tmp, size);
return 0;
}
int v86_mem_init(void)
{
u8 tmp[4];
if (real_mem_init())
return 1;
/*
* We have to map the IVTBDA as shared. Without it, setting video
* modes will not work correctly on some cards (e.g. nVidia GeForce
* 8600M, PCI ID 10de:0425).
*/
mem_low = map_file(NULL, IVTBDA_SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED, "/dev/mem", IVTBDA_BASE);
if (!mem_low) {
real_mem_deinit();
return 1;
}
/* Try to find the start of the EBDA */
ebda_start = (*(u16*)(mem_low + 0x40e)) << 4;
if (!ebda_start || ebda_start > EBDA_BASE)
ebda_start = EBDA_BASE;
if (get_bytes_from_phys(ebda_start, 1, tmp)) {
ulog(LOG_WARNING, "Failed to read EBDA size from %x. Ignoring EBDA.", ebda_start);
} else {
/* The first byte in the EBDA is its size in kB */
ebda_size = ((u32) tmp[0]) << 10;
if (ebda_start + ebda_size > VRAM_BASE) {
ulog(LOG_WARNING, "EBDA too big (%x), truncating.", ebda_size);
ebda_size = VRAM_BASE - ebda_start;
}
/* Map the EBDA */
ulog(LOG_DEBUG, "EBDA at %5x-%5x\n", ebda_start, ebda_start + ebda_size - 1);
u32 t = ebda_start & -getpagesize();
if (t) {
ebda_diff = ebda_start - t;
}
mem_ebda = map_file(NULL, ebda_size + ebda_diff, PROT_READ | PROT_WRITE, MAP_SHARED, "/dev/mem", ebda_start - ebda_diff);
if (!mem_ebda) {
ulog(LOG_WARNING, "Failed to mmap EBDA. Proceeding without it.");
}
}
/* Map the Video RAM */
mem_vram = map_file(NULL, VRAM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, "/dev/mem", VRAM_BASE);
if (!mem_vram) {
ulog(LOG_ERR, "Failed to mmap the Video RAM.");
v86_mem_cleanup();
return 1;
}
/* Map the Video BIOS */
get_bytes_from_phys(VBIOS_BASE, 4, tmp);
if (tmp[0] != 0x55 || tmp[1] != 0xAA) {
ulog(LOG_ERR, "Video BIOS not found at %x.", VBIOS_BASE);
v86_mem_cleanup();
return 1;
}
vbios_size = tmp[2] * 0x200;
ulog(LOG_DEBUG, "VBIOS at %5x-%5x\n", VBIOS_BASE, VBIOS_BASE + vbios_size - 1);
mem_vbios = map_file(NULL, vbios_size, PROT_READ,
MAP_SHARED, "/dev/mem", VBIOS_BASE);
if (!mem_vbios) {
ulog(LOG_ERR, "Failed to mmap the Video BIOS.");
v86_mem_cleanup();
return 1;
}
/* Map the system BIOS */
mem_sbios = map_file(NULL, SBIOS_SIZE, PROT_READ,
MAP_SHARED, "/dev/mem", SBIOS_BASE);
if (!mem_sbios) {
ulog(LOG_ERR, "Failed to mmap the System BIOS as %5x.", SBIOS_BASE);
v86_mem_cleanup();
return 1;
}
return 0;
}
void v86_mem_cleanup(void)
{
if (mem_low)
munmap(mem_low, IVTBDA_SIZE);
if (mem_ebda)
munmap(mem_ebda, ebda_size + ebda_diff);
if (mem_vram)
munmap(mem_vram, VRAM_SIZE);
if (mem_vbios)
munmap(mem_vbios, vbios_size);
if (mem_sbios)
munmap(mem_sbios, SBIOS_SIZE);
real_mem_deinit();
}
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