static int set_bios_mode(u8 mode)
{
struct biosregs ireg, oreg;
u8 new_mode;
initregs(&ireg);
ireg.al = mode; /* AH=0x00 Set Video Mode */
intcall(0x10, &ireg, NULL);
ireg.ah = 0x0f; /* Get Current Video Mode */
intcall(0x10, &ireg, &oreg);
do_restore = 1; /* Assume video contents were lost */
/* Not all BIOSes are clean with the top bit */
new_mode = oreg.al & 0x7f;
if (new_mode == mode)
return 0; /* Mode change OK */
#ifndef _WAKEUP
if (new_mode != boot_params.screen_info.orig_video_mode) {
/* Mode setting failed, but we didn't end up where we
started. That's bad. Try to revert to the original
video mode. */
ireg.ax = boot_params.screen_info.orig_video_mode;
intcall(0x10, &ireg, NULL);
}
#endif
return -1;
}
static int detect_memory_e801(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ax = 0xe801;
intcall(0x15, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
return -1;
/* */
if (oreg.cx || oreg.dx) {
oreg.ax = oreg.cx;
oreg.bx = oreg.dx;
}
if (oreg.ax > 15*1024) {
return -1; /* */
} else if (oreg.ax == 15*1024) {
boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
} else {
/*
*/
boot_params.alt_mem_k = oreg.ax;
}
return 0;
}
void cleanscreen(void) {
struct biosregs ireg;
initregs(&ireg);
ireg.bh = 0x0f;
ireg.cx = 0x0;
ireg.dh = 24;
ireg.dl = 79;
ireg.ax = 0x0600;
intcall(0x10, &ireg, NULL);
initregs(&ireg);
ireg.ah = 0x2;
ireg.bx = 0;
ireg.dx = 0;
intcall(0x10, &ireg, NULL);
}
static int detect_memory_e801(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ax = 0xe801;
intcall(0x15, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
return -1;
/* Do we really need to do this? */
if (oreg.cx || oreg.dx) {
oreg.ax = oreg.cx;
oreg.bx = oreg.dx;
}
if (oreg.ax > 15*1024) {
return -1; /* Bogus! */
} else if (oreg.ax == 15*1024) {
boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
} else {
/*
* This ignores memory above 16MB if we have a memory
* hole there. If someone actually finds a machine
* with a memory hole at 16MB and no support for
* 0E820h they should probably generate a fake e820
* map.
*/
boot_params.alt_mem_k = oreg.ax;
}
return 0;
}
static void __bootcode enable_a20_bios(void)
{
struct biosregs ireg;
initregs(&ireg);
ireg.ax = 0x2401;
intcall(0x15, &ireg, NULL);
}
static int kbd_pending(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ah = 0x01;
intcall(0x16, &ireg, &oreg);
return !(oreg.eflags & X86_EFLAGS_ZF);
}
/*
* Read from the keyboard
*/
int getchar(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
/* ireg.ah = 0x00; */
intcall(0x16, &ireg, &oreg);
return oreg.al;
}
static u8 gettime(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ah = 0x02;
intcall(0x1a, &ireg, &oreg);
return oreg.dh;
}
int query_apm_bios(void)
{
struct biosregs ireg, oreg;
/* APM BIOS installation check */
initregs(&ireg);
ireg.ah = 0x53;
intcall(0x15, &ireg, &oreg);
if (oreg.flags & X86_EFLAGS_CF)
return -1; /* No APM BIOS */
if (oreg.bx != 0x504d) /* "PM" signature */
return -1;
if (!(oreg.cx & 0x02)) /* 32 bits supported? */
return -1;
/* Disconnect first, just in case */
ireg.al = 0x04;
intcall(0x15, &ireg, NULL);
/* 32-bit connect */
ireg.al = 0x03;
intcall(0x15, &ireg, &oreg);
boot_params.apm_bios_info.cseg = oreg.ax;
boot_params.apm_bios_info.offset = oreg.ebx;
boot_params.apm_bios_info.cseg_16 = oreg.cx;
boot_params.apm_bios_info.dseg = oreg.dx;
boot_params.apm_bios_info.cseg_len = oreg.si;
boot_params.apm_bios_info.cseg_16_len = oreg.hsi;
boot_params.apm_bios_info.dseg_len = oreg.di;
if (oreg.flags & X86_EFLAGS_CF)
return -1;
/* Redo the installation check as the 32-bit connect;
some BIOSes return different flags this way... */
ireg.al = 0x00;
intcall(0x15, &ireg, &oreg);
if ((oreg.eflags & X86_EFLAGS_CF) || oreg.bx != 0x504d) {
/* Failure with 32-bit connect, try to disconect and ignore */
ireg.al = 0x04;
intcall(0x15, &ireg, NULL);
return -1;
}
boot_params.apm_bios_info.version = oreg.ax;
boot_params.apm_bios_info.flags = oreg.cx;
return 0;
}
static void __attribute__((section(".inittext"))) bios_putchar(int ch)
{
struct biosregs ireg;
initregs(&ireg);
ireg.bx = 0x0007;
ireg.cx = 0x0001;
ireg.ah = 0x0e;
ireg.al = ch;
intcall(0x10, &ireg, NULL);
}
static int detect_memory_e820(void)
{
int count = 0;
struct biosregs ireg, oreg;
struct e820entry *desc = boot_params.e820_map;
static struct e820entry buf; /* */
initregs(&ireg);
ireg.ax = 0xe820;
ireg.cx = sizeof buf;
ireg.edx = SMAP;
ireg.di = (size_t)&buf;
/*
*/
do {
intcall(0x15, &ireg, &oreg);
ireg.ebx = oreg.ebx; /* */
/*
*/
if (oreg.eflags & X86_EFLAGS_CF)
break;
/*
*/
if (oreg.eax != SMAP) {
count = 0;
break;
}
*desc++ = buf;
count++;
} while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_map));
return boot_params.e820_entries = count;
}
static int detect_memory_e820(void)
{
int count = 0;
struct biosregs ireg, oreg;
struct e820entry *desc = boot_params.e820_map;
static struct e820entry buf; /* static so it is zeroed */
initregs(&ireg);
ireg.ax = 0xe820;
ireg.cx = sizeof buf;
ireg.edx = SMAP;
ireg.di = (size_t)&buf;
/*
* Note: at least one BIOS is known which assumes that the
* buffer pointed to by one e820 call is the same one as
* the previous call, and only changes modified fields. Therefore,
* we use a temporary buffer and copy the results entry by entry.
*
* This routine deliberately does not try to account for
* ACPI 3+ extended attributes. This is because there are
* BIOSes in the field which report zero for the valid bit for
* all ranges, and we don't currently make any use of the
* other attribute bits. Revisit this if we see the extended
* attribute bits deployed in a meaningful way in the future.
*/
do {
intcall(0x15, &ireg, &oreg);
ireg.ebx = oreg.ebx; /* for next iteration... */
/* BIOSes which terminate the chain with CF = 1 as opposed
to %ebx = 0 don't always report the SMAP signature on
the final, failing, probe. */
if (oreg.eflags & X86_EFLAGS_CF)
break;
/* 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 != SMAP) {
count = 0;
break;
}
*desc++ = buf;
count++;
} while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_map));
return boot_params.e820_entries = count;
}
/**
@brief 0x88 Interrupt 명령으로 메모리\n
1Kbyte 단위의 메모리 크기를 확인한다.\n
확인 가능한 최대 메모리 크기는 64M + 1M 이다.\n
확인된 결과값은 boot_params.screen_info.ext_mem_k 에 저장된다.
@return 성공시:0, 실패시:-1
*/
static int detect_memory_88(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ah = 0x88;
intcall(0x15, &ireg, &oreg);
boot_params.screen_info.ext_mem_k = oreg.ax;
return -(oreg.eflags & X86_EFLAGS_CF); /* 0 or -1 */
}
static int vesa_probe(void)
{
struct biosregs ireg, oreg;
u16 mode;
addr_t mode_ptr;
struct mode_info *mi;
int nmodes = 0;
video_vesa.modes = GET_HEAP(struct mode_info, 0);
initregs(&ireg);
ireg.ax = 0x4f00;
ireg.di = (size_t)&vginfo;
intcall(0x10, &ireg, &oreg);
if (oreg.ax != 0x004f ||
vginfo.signature != VESA_MAGIC ||
vginfo.version < 0x0102)
return 0; /* Not present */
set_fs(vginfo.video_mode_ptr.seg);
mode_ptr = vginfo.video_mode_ptr.off;
while ((mode = rdfs16(mode_ptr)) != 0xffff) {
mode_ptr += 2;
if (!heap_free(sizeof(struct mode_info)))
break; /* Heap full, can't save mode info */
if (mode & ~0x1ff)
continue;
memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
ireg.ax = 0x4f01;
ireg.cx = mode;
ireg.di = (size_t)&vminfo;
intcall(0x10, &ireg, &oreg);
if (oreg.ax != 0x004f)
continue;
if ((vminfo.mode_attr & 0x15) == 0x05) {
/* Text Mode, TTY BIOS supported,
supported by hardware */
mi = GET_HEAP(struct mode_info, 1);
mi->mode = mode + VIDEO_FIRST_VESA;
mi->depth = 0; /* text */
mi->x = vminfo.h_res;
mi->y = vminfo.v_res;
nmodes++;
} else if ((vminfo.mode_attr & 0x99) == 0x99 &&
void putchar(int ch) {
struct biosregs ireg;
if (ch == '\n')
putchar('\r'); /* \n -> \r\n */
initregs(&ireg);
ireg.bx = 0x0007;
ireg.cx = 0x0001;
ireg.ah = 0x0e;
ireg.al = ch;
intcall(0x10, &ireg, NULL);
}
static int read_mbr(u8 devno, void *buf)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ax = 0x0201;
ireg.cx = 0x0001;
ireg.dl = devno;
ireg.bx = (size_t)buf;
intcall(0x13, &ireg, &oreg);
return -(oreg.eflags & X86_EFLAGS_CF);
}
void __attribute__((section(".inittext"))) putchar(int ch)
{
struct biosregs ireg;
if (ch == '\n')
putchar('\r'); /* \n -> \r\n */
initregs(&ireg);
ireg.bx = 0x0007;
ireg.cx = 0x0001;
ireg.ah = 0x0e;
ireg.al = ch;
intcall(0x10, &ireg, NULL);
}
static int get_edd_info(u8 devno, struct edd_info *ei)
{
struct biosregs ireg, oreg;
memset(ei, 0, sizeof *ei);
initregs(&ireg);
ireg.ah = 0x41;
ireg.bx = EDDMAGIC1;
ireg.dl = devno;
intcall(0x13, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
return -1;
if (oreg.bx != EDDMAGIC2)
return -1;
ei->device = devno;
ei->version = oreg.ah;
ei->interface_support = oreg.cx;
ei->params.length = sizeof(ei->params);
ireg.ah = 0x48;
ireg.si = (size_t)&ei->params;
intcall(0x13, &ireg, &oreg);
ireg.ah = 0x08;
ireg.es = 0;
intcall(0x13, &ireg, &oreg);
if (!(oreg.eflags & X86_EFLAGS_CF)) {
ei->legacy_max_cylinder = oreg.ch + ((oreg.cl & 0xc0) << 2);
ei->legacy_max_head = oreg.dh;
ei->legacy_sectors_per_track = oreg.cl & 0x3f;
}
return 0;
}
int query_mca(void)
{
struct biosregs ireg, oreg;
u16 len;
initregs(&ireg);
ireg.ah = 0xc0;
intcall(0x15, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
return -1; /* No MCA present */
set_fs(oreg.es);
len = rdfs16(oreg.bx);
if (len > sizeof(boot_params.sys_desc_table))
len = sizeof(boot_params.sys_desc_table);
copy_from_fs(&boot_params.sys_desc_table, oreg.bx, len);
return 0;
}
/**
@brief 0xe801 Interrupt 명령을 통한 Memory map을 확인한다.\n
확인된 Memory map 정보는 boot_params 에 저장된다.\n
확인하는 사항은 전체 메모리 맵 구성의 크기이다.\n
확인 가능한 최대 메모리 크기는 4G + 16M 이다.\n
최대 확인 가능한 메모리 크기까지만 표현한다.\n
결과값은 boot_params.alt_mem_k 에 저장된다.
@return 성공시:0, 실패시:-1
*/
static int detect_memory_e801(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ax = 0xe801;
// 0xe801 : 0xe820(2002), 0xe801(1994) 2002 년 이전의 CPU는 e801
// 명령으로만 Memory map 을 확인할 수 있으므로...
intcall(0x15, &ireg, &oreg);
// 연산 결과
// ax : Kbyte 단위의 1 ~ 15 * 1024 사이의 크기 값.(표현가능한 크기: 1Kbyte ~ 15 Mbyte)
// bx : 64KByte 단위의 크기값. (최대 4GB)
if (oreg.eflags & X86_EFLAGS_CF)
return -1;
/* Do we really need to do this? */
if (oreg.cx || oreg.dx) {
oreg.ax = oreg.cx;
oreg.bx = oreg.dx;
}
if (oreg.ax > 15*1024) {
return -1; /* Bogus! */
} else if (oreg.ax == 15*1024) {
boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
} else {
/*
* This ignores memory above 16MB if we have a memory
* hole there. If someone actually finds a machine
* with a memory hole at 16MB and no support for
* 0E820h they should probably generate a fake e820
* map.
*/
boot_params.alt_mem_k = oreg.ax;
}
return 0;
}
static int detect_memory_e801(void)
{
struct biosregs ireg, oreg;
initregs(&ireg);
ireg.ax = 0xe801;
intcall(0x15, &ireg, &oreg);
if (oreg.eflags & X86_EFLAGS_CF)
return -1;
/* Do we really need to do this? */
if (oreg.cx || oreg.dx) {
oreg.ax = oreg.cx;
oreg.bx = oreg.dx;
}
if (oreg.ax > 15*1024) {
return -1; /* Bogus! */
} else if (oreg.ax == 15*1024) {
<<<<<<< HEAD
boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax;
=======
/**
@brief e820 Interrupt 를 통한 현재 Memory map 구성을 확인하고 e820 정보를 e820_map에 입력한다.
@return 성공시: 확인된 memory map 구성 갯수, 실패시:0
*/
static int detect_memory_e820(void)
{
int count = 0;
struct biosregs ireg, oreg;
struct e820entry *desc = boot_params.e820_map;
static struct e820entry buf; /* static so it is zeroed */
initregs(&ireg);
ireg.ax = 0xe820; // 0xE820
// 0xE820 : returns a memory map of all the installed RAM,
// and of physical memory ranges reserved by the BIOS.
// http://www.uruk.org/orig-grub/mem64mb.html
ireg.cx = sizeof buf;
ireg.edx = SMAP; /* 필요한 signature */
ireg.di = (size_t)&buf;
/*
* Note: at least one BIOS is known which assumes that the
* buffer pointed to by one e820 call is the same one as
* the previous call, and only changes modified fields. Therefore,
* we use a temporary buffer and copy the results entry by entry.
*
* This routine deliberately does not try to account for
* ACPI 3+ extended attributes. This is because there are
* BIOSes in the field which report zero for the valid bit for
* all ranges, and we don't currently make any use of the
* other attribute bits. Revisit this if we see the extended
* attribute bits deployed in a meaningful way in the future.
*/
do {
intcall(0x15, &ireg, &oreg);
// 0x15: ax(e820)
// &ireg : Input Register
// &oreg : Ouput Register
ireg.ebx = oreg.ebx; /* for next iteration... */
// ebx : Offset 주소.
// Input 의 경우 시작 Offset, Output의 경우 다음 Offset.
// 만약 Offset이 0 이면 끝을 의미한다.
/* BIOSes which terminate the chain with CF = 1 as opposed
to %ebx = 0 don't always report the SMAP signature on
the final, failing, probe. */
if (oreg.eflags & X86_EFLAGS_CF) // Error 발생시, CF Flag가 Set이 된다.
break;
/* 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. */
// 정상적인 검색 루프에서는 Return 값으로 oreg.eax 에 SMAP 값이 입력되어야 한다.
// 일부 BIOS 에서는 다른 값들이 올 수도 있지만 SMAP 이 아닌 경우,
// 모두 Error 로 간주한다.
if (oreg.eax != SMAP) {
count = 0;
break;
}
*desc++ = buf; /* e820 엔트리를 e820_map에 입력 */
count++;
// ireg.ebx = Next Search Memory Offset
} while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_map));
return boot_params.e820_entries = count; /* 총 갯수 */
}
