static void vga_recalc_vertical(void)
{
unsigned int font_size, rows;
u16 crtc;
u8 pt, ov;
set_fs(0);
font_size = rdfs8(0x485);
rows = force_y ? force_y : rdfs8(0x484)+1;
rows *= font_size;
rows--;
crtc = vga_crtc();
pt = in_idx(crtc, 0x11);
pt &= ~0x80;
out_idx(pt, crtc, 0x11);
out_idx((u8)rows, crtc, 0x12);
ov = in_idx(crtc, 0x07);
ov &= 0xbd;
ov |= (rows >> (8-1)) & 0x02;
ov |= (rows >> (9-6)) & 0x40;
out_idx(ov, crtc, 0x07);
}
/*
* Recalculate the vertical video cutoff (hack!)
*/
static void vga_recalc_vertical(void)
{
unsigned int font_size, rows;
u16 crtc;
u8 pt, ov;
set_fs(0);
font_size = rdfs8(0x485); /* BIOS: font size (pixels) */
rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */
rows *= font_size; /* Visible scan lines */
rows--; /* ... minus one */
crtc = vga_crtc();
pt = in_idx(crtc, 0x11);
pt &= ~0x80; /* Unlock CR0-7 */
out_idx(pt, crtc, 0x11);
out_idx((u8)rows, crtc, 0x12); /* Lower height register */
ov = in_idx(crtc, 0x07); /* Overflow register */
ov &= 0xbd;
ov |= (rows >> (8-1)) & 0x02;
ov |= (rows >> (9-6)) & 0x40;
out_idx(ov, crtc, 0x07);
}
/**
@brief
*/
static void vga_recalc_vertical(void)
{
unsigned int font_size, rows;
u16 crtc;
u8 pt, ov;
/*
0x485 : Point Height of Size (2Byte)
0x484 : Rows on the screen (2Byte)
*/
set_fs(0);
font_size = rdfs8(0x485); /* BIOS: font size (pixels) */
rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */
rows *= font_size; /* Visible scan lines */
rows--; /* ... minus one */
crtc = vga_crtc();
/*
CPU 에서 장치에 접근하는 방법은
Index Register Address, Data Register Address 을 이용하여 접근한다.
Index Register Address 에는 장치에서 관리하는 Register 중, 몇 번째 Register
에 접근할지 에 대한 정보(Index)가 입력되며, 1 Byte 의 크기(0 ~ 255) 까지의
값이 할당가능하다.
Data Register 에는 지정된 Index 번째에 해당하는 데이터가 입력된다.
Index Register Address 와 Data Register Address 는 항상 쌍으로 구성되며,
Index Register Address + 1 의 주소가 Data Register Address 가 된다
*/
pt = in_idx(crtc, 0x11);
pt &= ~0x80; /* Unlock CR0-7 */ // 최상위 비트를 끈다.
out_idx(pt, crtc, 0x11); // 쓰기가능하게 해준다.
// 11h R- native VGA with bit7=1 in end horizontal blanking (03h):
// end vertical retrace
// 11h -W end vertical retrace
// bit7 : VGA: protection bit
// =0 enable write access to 00h-07h
// =1 read only regs 00h-07h with the exception
// of bit4 in 07h. ET4000: protect 35h also.
// rows의 아래 8비트를 먼저 써주고 8번 9번 비트를 위치에 맞게 OR해 넣는다.
out_idx((u8)rows, crtc, 0x12); /* Lower height register */
ov = in_idx(crtc, 0x07); /* Overflow register */
ov &= 0xbd; // 1011 1101
ov |= (rows >> (8-1)) & 0x02; // bit 8 of vertical display end
ov |= (rows >> (9-6)) & 0x40; // bit 9 of "
out_idx(ov, crtc, 0x07);
}
int cmdline_find_option_bool(const char *option)
{
u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;
addr_t cptr;
char c;
int pos = 0, wstart = 0;
const char *opptr = NULL;
enum {
st_wordstart,
st_wordcmp,
st_wordskip,
} state = st_wordstart;
if (!cmdline_ptr || cmdline_ptr >= 0x100000)
return -1;
cptr = cmdline_ptr & 0xf;
set_fs(cmdline_ptr >> 4);
while (cptr < 0x10000) {
c = rdfs8(cptr++);
pos++;
switch (state) {
case st_wordstart:
if (!c)
return 0;
else if (myisspace(c))
break;
state = st_wordcmp;
opptr = option;
wstart = pos;
case st_wordcmp:
if (!*opptr)
if (!c || myisspace(c))
return wstart;
else
state = st_wordskip;
else if (!c)
return 0;
else if (c != *opptr++)
state = st_wordskip;
break;
case st_wordskip:
if (!c)
return 0;
else if (myisspace(c))
state = st_wordstart;
break;
}
}
return 0;
}
/*
* Find a boolean option (like quiet,noapic,nosmp....)
*
* Returns the position of that option (starts counting with 1)
* or 0 on not found
*/
int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option)
{
addr_t cptr;
char c;
int pos = 0, wstart = 0;
const char *opptr = NULL;
enum {
st_wordstart, /* Start of word/after whitespace */
st_wordcmp, /* Comparing this word */
st_wordskip, /* Miscompare, skip */
} state = st_wordstart;
if (!cmdline_ptr || cmdline_ptr >= 0x100000)
return -1; /* No command line, or inaccessible */
cptr = cmdline_ptr & 0xf;
set_fs(cmdline_ptr >> 4);
while (cptr < 0x10000) {
c = rdfs8(cptr++);
pos++;
switch (state) {
case st_wordstart:
if (!c)
return 0;
else if (myisspace(c))
break;
state = st_wordcmp;
opptr = option;
wstart = pos;
/* fall through */
case st_wordcmp:
if (!*opptr)
if (!c || myisspace(c))
return wstart;
else
state = st_wordskip;
else if (!c)
return 0;
else if (c != *opptr++)
state = st_wordskip;
break;
case st_wordskip:
if (!c)
return 0;
else if (myisspace(c))
state = st_wordstart;
break;
}
}
return 0; /* Buffer overrun */
}
static int bios_probe(void)
{
u8 mode;
#ifdef _WAKEUP
u8 saved_mode = 0x03;
#else
u8 saved_mode = boot_params.screen_info.orig_video_mode;
#endif
u16 crtc;
struct mode_info *mi;
int nmodes = 0;
if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA)
return 0;
set_fs(0);
crtc = vga_crtc();
video_bios.modes = GET_HEAP(struct mode_info, 0);
for (mode = 0x14; mode <= 0x7f; mode++) {
if (!heap_free(sizeof(struct mode_info)))
break;
if (mode_defined(VIDEO_FIRST_BIOS+mode))
continue;
if (set_bios_mode(mode))
continue;
/* Try to verify that it's a text mode. */
/* Attribute Controller: make graphics controller disabled */
if (in_idx(0x3c0, 0x10) & 0x01)
continue;
/* Graphics Controller: verify Alpha addressing enabled */
if (in_idx(0x3ce, 0x06) & 0x01)
continue;
/* CRTC cursor location low should be zero(?) */
if (in_idx(crtc, 0x0f))
continue;
mi = GET_HEAP(struct mode_info, 1);
mi->mode = VIDEO_FIRST_BIOS+mode;
mi->depth = 0; /* text */
mi->x = rdfs16(0x44a);
mi->y = rdfs8(0x484)+1;
nmodes++;
}
set_bios_mode(saved_mode);
return nmodes;
}
/*
* Find a non-boolean option, that is, "option=argument". In accordance
* with standard Linux practice, if this option is repeated, this returns
* the last instance on the command line.
*
* Returns the length of the argument (regardless of if it was
* truncated to fit in the buffer), or -1 on not found.
*/
int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize)
{
addr_t cptr;
char c;
int len = -1;
const char *opptr = NULL;
char *bufptr = buffer;
enum {
st_wordstart, /* Start of word/after whitespace */
st_wordcmp, /* Comparing this word */
st_wordskip, /* Miscompare, skip */
st_bufcpy /* Copying this to buffer */
} state = st_wordstart;
if (!cmdline_ptr || cmdline_ptr >= 0x100000)
return -1; /* No command line, or inaccessible */
cptr = cmdline_ptr & 0xf;
set_fs(cmdline_ptr >> 4);
while (cptr < 0x10000 && (c = rdfs8(cptr++))) {
switch (state) {
case st_wordstart:
if (myisspace(c))
break;
/* else */
state = st_wordcmp;
opptr = option;
/* fall through */
case st_wordcmp:
if (c == '=' && !*opptr) {
len = 0;
bufptr = buffer;
state = st_bufcpy;
} else if (myisspace(c)) {
state = st_wordstart;
} else if (c != *opptr++) {
state = st_wordskip;
}
break;
case st_wordskip:
if (myisspace(c))
state = st_wordstart;
break;
case st_bufcpy:
if (myisspace(c)) {
state = st_wordstart;
} else {
if (len < bufsize-1)
*bufptr++ = c;
len++;
}
break;
}
}
if (bufsize)
*bufptr = '\0';
return len;
}
int cmdline_find_option(const char *option, char *buffer, int bufsize)
{
u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;
addr_t cptr;
char c;
int len = -1;
const char *opptr = NULL;
char *bufptr = buffer;
enum {
st_wordstart,
st_wordcmp,
st_wordskip,
st_bufcpy
} state = st_wordstart;
if (!cmdline_ptr || cmdline_ptr >= 0x100000)
return -1;
cptr = cmdline_ptr & 0xf;
set_fs(cmdline_ptr >> 4);
while (cptr < 0x10000 && (c = rdfs8(cptr++))) {
switch (state) {
case st_wordstart:
if (myisspace(c))
break;
state = st_wordcmp;
opptr = option;
case st_wordcmp:
if (c == '=' && !*opptr) {
len = 0;
bufptr = buffer;
state = st_bufcpy;
} else if (myisspace(c)) {
state = st_wordstart;
} else if (c != *opptr++) {
state = st_wordskip;
}
break;
case st_wordskip:
if (myisspace(c))
state = st_wordstart;
break;
case st_bufcpy:
if (myisspace(c)) {
state = st_wordstart;
} else {
if (len < bufsize-1)
*bufptr++ = c;
len++;
}
break;
}
}
if (bufsize)
*bufptr = '\0';
return len;
}
/*
* Find a non-boolean option, that is, "option=argument". In accordance
* with standard Linux practice, if this option is repeated, this returns
* the last instance on the command line.
*
* Returns the length of the argument (regardless of if it was
* truncated to fit in the buffer), or -1 on not found.
*/
int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize)
{
addr_t cptr;
char c;
int len = -1;
const char *opptr = NULL;
char *bufptr = buffer;
enum {
st_wordstart, /* Start of word/after whitespace */
st_wordcmp, /* Comparing this word */
st_wordskip, /* Miscompare, skip */
st_bufcpy /* Copying this to buffer */
} state = st_wordstart;
if (!cmdline_ptr || cmdline_ptr >= 0x100000) // cmdline 포인터가 없거나 1M이상이면 에러
return -1; /* No command line, or inaccessible */
cptr = cmdline_ptr & 0xf; // cmdline_ptr의 오프셋
set_fs(cmdline_ptr >> 4); // cmdline_ptr의 세그먼트 값
// cmdline에서 옵션을 찾는다.
while (cptr < 0x10000 && (c = rdfs8(cptr++))) {
switch (state) {
case st_wordstart:
if (myisspace(c)) // 맨 처음 혹은 스페이스(<32)가 여러개 오면 break 해버린다.
break;
/* else */
state = st_wordcmp; // 구분자 후에 문자가 있으면 wordcmp로 상태 변환
opptr = option; // 찾을 옵션
/* fall through */
// 아래로 계속된다.
case st_wordcmp:
if (c == '=' && !*opptr) {
len = 0; // 길이 리셋
bufptr = buffer;
state = st_bufcpy; // 일치한다. bufcpy로 상태전환
} else if (myisspace(c)) {
state = st_wordstart; // "="이 없다. 다시 비교
} else if (c != *opptr++) {
state = st_wordskip; // 일치하지 않음
}
break; // 문자가 일치한다. cmp 상태 그대로 다시 비교
case st_wordskip: // skip은 문자열이 일치하지 않은 상태
if (myisspace(c)) // 구분자가 오면 새로 비교 시작
state = st_wordstart;
break;
case st_bufcpy:
if (myisspace(c)) {
state = st_wordstart; // 구분자가 오기전까지 복사
} else {
if (len < bufsize-1)
*bufptr++ = c; // 버퍼 크기를 넘지 않으면 복사
len++;
}
break;
}
}
if (bufsize)
*bufptr = '\0'; // 버퍼 끝은 NUL
return len; // 옵션 길이를 리턴. 일치하는게 없으면 -1
}