//bootpack.c 完整代码 #include <stdio.h> void io_hlt(void); void io_cli(void); void io_out8(int port, int data); int io_load_eflags(void); void io_store_eflags(int eflags); void init_palette(void); void set_palette(int start, int end, unsigned char *rgb); void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, int x1, int y1); void init_screen8(char *vram, int x, int y); void putfont8(char *vram, int xsize, int x, int y, char c, char *font); void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s); void init_mouse_cursor8(char *mouse, char bc); void putblock8_8(char *vram, int vxsize, int pxsize, int pysize, int px0, int py0, char *buf, int bxsize); #define COL8_000000 0 #define COL8_FF0000 1 #define COL8_00FF00 2 #define COL8_FFFF00 3 #define COL8_0000FF 4 #define COL8_FF00FF 5 #define COL8_00FFFF 6 #define COL8_FFFFFF 7 #define COL8_C6C6C6 8 #define COL8_840000 9 #define COL8_008400 10 #define COL8_848400 11 #define COL8_000084 12 #define COL8_840084 13 #define COL8_008484 14 #define COL8_848484 15 //接受启动信息写成结构体的形式 P89.接着从asmhead.nas中读取启动信息数据（启动地址和内容） //注意在第一天中，我们已经把asmhead.nas中的信息写到了镜像中。每次系统启动时，首先载入镜像，然后读到asmhead.nas中的内容启动 struct BOOTINFO { char cyls, leds, vmode, reserve; short scrnx, scrny; char *vram; }; struct SEGMENT_DESCRIPTOR { //GDT的内容；8字节 short limit_low, base_low; char base_mid, access_right; char limit_high, base_high; }; struct GATE_DESCRIPTOR { //IDT的内容，8字节 short offset_low, selector; char dw_count, access_right; short offset_high; }; void init_gdtidt(void); void set_segmdesc(struct SEGMENT_DESCRIPTOR *sd, unsigned int limit, int base, int ar); void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar); void load_gdtr(int limit, int addr); void load_idtr(int limit, int addr); void HariMain(void) { struct BOOTINFO *binfo = (struct BOOTINFO *) 0x0ff0; char s[40], mcursor[256]; int mx, my; init_gdtidt(); init_palette(); init_screen8(binfo->vram, binfo->scrnx, binfo->scrny); //所谓的使用箭头记号-> mx = (binfo->scrnx - 16) / 2; /* 启动信息结构体BOOTINFO 从asmhead.nas中读取启动信息数据*/ my = (binfo->scrny - 28 - 16) / 2; init_mouse_cursor8(mcursor, COL8_008484); //初始化并显示鼠标指针 putblock8_8(binfo->vram, binfo->scrnx, 16, 16, mx, my, mcursor, 16); sprintf(s, "(%d, %d)", mx, my); //显示变量，先把内容放到字符串s中 putfonts8_asc(binfo->vram, binfo->scrnx, 0, 0, COL8_FFFFFF, s); //接着把字符串s显示出来 for (;;) { io_hlt(); } } void init_palette(void) { static unsigned char table_rgb[16 * 3] = { 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0xff, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc6, 0xc6, 0xc6, 0x84, 0x00, 0x00, 0x00, 0x84, 0x00, 0x84, 0x84, 0x00, 0x00, 0x00, 0x84, 0x84, 0x00, 0x84, 0x00, 0x84, 0x84, 0x84, 0x84, 0x84 }; set_palette(0, 15, table_rgb); return; } void set_palette(int start, int end, unsigned char *rgb) { int i, eflags; eflags = io_load_eflags(); io_cli(); io_out8(0x03c8, start); for (i = start; i <= end; i++) { io_out8(0x03c9, rgb[0] / 4); io_out8(0x03c9, rgb[1] / 4); io_out8(0x03c9, rgb[2] / 4); rgb += 3; } io_store_eflags(eflags); return; } void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, int x1, int y1) { int x, y; for (y = y0; y <= y1; y++) { for (x = x0; x <= x1; x++) vram[y * xsize + x] = c; } return; } void init_screen8(char *vram, int x, int y) { boxfill8(vram, x, COL8_008484, 0, 0, x - 1, y - 29); boxfill8(vram, x, COL8_C6C6C6, 0, y - 28, x - 1, y - 28); boxfill8(vram, x, COL8_FFFFFF, 0, y - 27, x - 1, y - 27); boxfill8(vram, x, COL8_C6C6C6, 0, y - 26, x - 1, y - 1); boxfill8(vram, x, COL8_FFFFFF, 3, y - 24, 59, y - 24); boxfill8(vram, x, COL8_FFFFFF, 2, y - 24, 2, y - 4); boxfill8(vram, x, COL8_848484, 3, y - 4, 59, y - 4); boxfill8(vram, x, COL8_848484, 59, y - 23, 59, y - 5); boxfill8(vram, x, COL8_000000, 2, y - 3, 59, y - 3); boxfill8(vram, x, COL8_000000, 60, y - 24, 60, y - 3); boxfill8(vram, x, COL8_848484, x - 47, y - 24, x - 4, y - 24); boxfill8(vram, x, COL8_848484, x - 47, y - 23, x - 47, y - 4); boxfill8(vram, x, COL8_FFFFFF, x - 47, y - 3, x - 4, y - 3); boxfill8(vram, x, COL8_FFFFFF, x - 3, y - 24, x - 3, y - 3); return; } //输出，显示字符 void putfont8(char *vram, int xsize, int x, int y, char c, char *font) { int i; char *p, d /* data */; for (i = 0; i < 16; i++) { p = vram + (y + i) * xsize + x; d = font[i]; if ((d & 0x80) != 0) { p[0] = c; } if ((d & 0x40) != 0) { p[1] = c; } if ((d & 0x20) != 0) { p[2] = c; } if ((d & 0x10) != 0) { p[3] = c; } if ((d & 0x08) != 0) { p[4] = c; } if ((d & 0x04) != 0) { p[5] = c; } if ((d & 0x02) != 0) { p[6] = c; } if ((d & 0x01) != 0) { p[7] = c; } } return; } //输出，显示字符串 void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s) { extern char hankaku[4096]; for (; *s != 0x00; s++) { putfont8(vram, xsize, x, y, c, hankaku + *s * 16); x += 8; } return; } void init_mouse_cursor8(char *mouse, char bc) /* 准备，初始化鼠标指针 16*16=512字符（字节）*/ { static char cursor[16][16] = { "**************..", "*OOOOOOOOOOO*...", "*OOOOOOOOOO*....", "*OOOOOOOOO*.....", "*OOOOOOOO*......", "*OOOOOOO*.......", "*OOOOOOO*.......", "*OOOOOOOO*......", "*OOOO**OOO*.....", "*OOO*..*OOO*....", "*OO*....*OOO*...", "*O*......*OOO*..", "**........*OOO*.", "*..........*OOO*", "............*OO*", ".............***" }; int x, y; for (y = 0; y < 16; y++) { for (x = 0; x < 16; x++) { if (cursor[y][x] == '*') { mouse[y * 16 + x] = COL8_000000; } if (cursor[y][x] == 'O') { mouse[y * 16 + x] = COL8_FFFFFF; } if (cursor[y][x] == '.') { mouse[y * 16 + x] = bc; } } } return; } //这里显示鼠标指针； void putblock8_8(char *vram, int vxsize, int pxsize, int pysize, int px0, int py0, char *buf, int bxsize) { int x, y; for (y = 0; y < pysize; y++) { for (x = 0; x < pxsize; x++) { vram[(py0 + y) * vxsize + (px0 + x)] = buf[y * bxsize + x]; } } return; } void init_gdtidt(void) //GDT和IDT的初始化 { struct SEGMENT_DESCRIPTOR *gdt = (struct SEGMENT_DESCRIPTOR *) 0x00270000; struct GATE_DESCRIPTOR *idt = (struct GATE_DESCRIPTOR *) 0x0026f800; int i; /* GDT初始化 */ for (i = 0; i < 8192; i++) { //i每次加一；但是gdt指向8字节的结构体；结果地址增加了8 set_segmdesc(gdt + i, 0, 0, 0); //gdt*（地址）每次+8 } set_segmdesc(gdt + 1, 0xffffffff, 0x00000000, 0x4092); //段号为1；大小4G 表示CPU管理的全部内存 set_segmdesc(gdt + 2, 0x0007ffff, 0x00280000, 0x409a); //段号位2； 大小512K 为bootpack.hrb准备 load_gdtr(0xffff, 0x00270000); //GDT 0x270000-0x27ffff 借助汇编语言的力量给寄存器GDTR赋值 /* IDT初始化 */ for (i = 0; i < 256; i++) { //和上面一样 set_gatedesc(idt + i, 0, 0, 0); } //IDT 0x26f800-0x26ffff load_idtr(0x7ff, 0x0026f800); //向寄存器IDTR赋值 return; } void set_segmdesc(struct SEGMENT_DESCRIPTOR *sd, unsigned int limit, int base, int ar) { if (limit > 0xfffff) { ar |= 0x8000; /* G_bit = 1 */ limit /= 0x1000; } sd->limit_low = limit & 0xffff; sd->base_low = base & 0xffff; sd->base_mid = (base >> 16) & 0xff; sd->access_right = ar & 0xff; sd->limit_high = ((limit >> 16) & 0x0f) | ((ar >> 8) & 0xf0); sd->base_high = (base >> 24) & 0xff; return; } void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar) { gd->offset_low = offset & 0xffff; gd->selector = selector; gd->dw_count = (ar >> 8) & 0xff; gd->access_right = ar & 0xff; gd->offset_high = (offset >> 16) & 0xffff; return; }
harib02a:
P89 这里做的就是数值写入asmhead.nas中，然后取值；
而不是将这些数值直接写入程序bootpack.c中
//bootpack.c节选 void HariMain(void) { char *vram; int xsize, ysize; short *binfo_scrnx, *binfo_scrny; int *binfo_vram;
init_palette(); binfo_scrnx = (short *) 0x0ff4; binfo_scrny = (short *) 0x0ff6; binfo_vram = (int *) 0x0ff8; xsize = *binfo_scrnx; ysize = *binfo_scrny; vram = (char *) *binfo_vram; init_screen(vram, xsize, ysize); for (;;) { io_hlt(); } }
harib02b:
这次使用的是结构体的方法重新写一遍，实现的内容是一样的
只是实现方法在这里使用了结构体的写法。如下：
//bootpack.c节选 //接受启动信息写成结构体的形式 P89.接着从asmhead.nas中读取启动信息数据（启动地址和内容） //注意在第一天中，我们已经把asmhead.nas中的信息写到了镜像中。每次系统启动时，首先载入镜像，然后读到asmhead.nas中的内容启动 struct BOOTINFO { char cyls, leds, vmode, reserve; short scrnx, scrny; char *vram; }; void HariMain(void) { char *vram; int xsize, ysize; struct BOOTINFO *binfo; init_palette(); binfo = (struct BOOTINFO *) 0x0ff0; xsize = (*binfo).scrnx; ysize = (*binfo).scrny; vram = (*binfo).vram; init_screen(vram, xsize, ysize); for (;;) { io_hlt(); } }
harib02c:
这一步在结构体的基础上，引入了箭头记号的C变成的方式
eg::xsize = (*binfo).scrnx 可以写成 xsize = binfo -> scrnx
进一步改进了程序，但实现的内容任然不变
void HariMain(void) { struct BOOTINFO *binfo = (struct BOOTINFO *) 0x0ff0; init_palette(); init_screen(binfo->vram, binfo->scrnx, binfo->scrny); for (;;) { io_hlt(); } }
harib02d:
P92 显示字符；
原理：字符使用8*16的像素点阵来表示，
1个字符是16个字节
建立了font结构体数组，用来表示像素点阵字符
函数purfont8()用来将像素点阵字符输出
//字符显示函数 void putfont8(char *vram, int xsize, int x, int y, char c, char *font) { int i; char *p, d /* data */; for (i = 0; i < 16; i++) { p = vram + (y + i) * xsize + x; d = font[i]; if ((d & 0x80) != 0) { p[0] = c; } if ((d & 0x40) != 0) { p[1] = c; } if ((d & 0x20) != 0) { p[2] = c; } if ((d & 0x10) != 0) { p[3] = c; } if ((d & 0x08) != 0) { p[4] = c; } if ((d & 0x04) != 0) { p[5] = c; } if ((d & 0x02) != 0) { p[6] = c; } if ((d & 0x01) != 0) { p[7] = c; } } return; }
harib02e:
P94 增加了字体的显示； 这里使用了OSASK的字体数据；
原理：相应了字体显示的像素点阵存储在hankaku.txt中。
每一个字体字符都有一个编号。直接查找调用即可
方法：用OSASK的专用编译器makefont.exe将hankaku.txt编译成hankaku.bin
再由连接器bin2obj.exer将hankaku.bin加上必须的接口信息和bootpack.obj链接
生成目标文件
//显示ABC 123 void HariMain(void) { struct BOOTINFO *binfo = (struct BOOTINFO *) 0x0ff0; extern char hankaku[4096]; init_palette(); init_screen(binfo->vram, binfo->scrnx, binfo->scrny); putfont8(binfo->vram, binfo->scrnx, 10, 0, COL8_FFFFFF, hankaku + 'A' * 16); putfont8(binfo->vram, binfo->scrnx, 16, 8, COL8_FFFFFF, hankaku + 'B' * 16); putfont8(binfo->vram, binfo->scrnx, 24, 8, COL8_FFFFFF, hankaku + 'C' * 16); putfont8(binfo->vram, binfo->scrnx, 40, 8, COL8_FFFFFF, hankaku + '1' * 16); putfont8(binfo->vram, binfo->scrnx, 48, 8, COL8_FFFFFF, hankaku + '2' * 16); putfont8(binfo->vram, binfo->scrnx, 56, 8, COL8_FFFFFF, hankaku + '3' * 16); for (;;) { io_hlt(); } }
harib02f:
接着笔者干脆写了一个函数用来专门显示字符串；putfonts8_asc();
//字符串显示函数 void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s) { extern char hankaku[4096]; for (; *s != 0x00; s++) { putfont8(vram, xsize, x, y, c, hankaku + *s * 16); x += 8; } return; }
harib02g:
P98 显示变量的值；虽然我们不能用prinft()函数；但是我们可以使用sprintf()函数
sprintf()将输出的内容写在内存中间。这个函数只对内存进行操作，可以应用于所有的操作系统
笔者还附带的介绍了一下sprintf（）的使用方法和格式；
sprintf(s, "scrnx = %d", binfo->scrnx); putfonts8_asc(binfo->vram, binfo->scrnx, 16, 64, COL8_FFFFFF, s);
harib02h:
P100 鼠标指针的显示。大小设定为16*16的字符数组的大小
内存空间：16*16=256字节；程序写在了init_mouse_cursor8中。
显示的原理和上面字符显示的原理一样；将buf中的数据复制到VARM中去就可以了
接下来笔者写了一个显示的函数putblock8_8()；教材100面有函数详细的介绍。
//bootpack.c 节选 void init_mouse_cursor8(char *mouse, char bc) /* 准备，初始化鼠标指针 16*16=512字符（字节）*/ { static char cursor[16][16] = { "**************..", "*OOOOOOOOOOO*...", "*OOOOOOOOOO*....", "*OOOOOOOOO*.....", "*OOOOOOOO*......", "*OOOOOOO*.......", "*OOOOOOO*.......", "*OOOOOOOO*......", "*OOOO**OOO*.....", "*OOO*..*OOO*....", "*OO*....*OOO*...", "*O*......*OOO*..", "**........*OOO*.", "*..........*OOO*", "............*OO*", ".............***" }; int x, y; for (y = 0; y < 16; y++) { for (x = 0; x < 16; x++) { if (cursor[y][x] == '*') { mouse[y * 16 + x] = COL8_000000; } if (cursor[y][x] == 'O') { mouse[y * 16 + x] = COL8_FFFFFF; } if (cursor[y][x] == '.') { mouse[y * 16 + x] = bc; } } } return; } //这里显示鼠标指针； void putblock8_8(char *vram, int vxsize, int pxsize, int pysize, int px0, int py0, char *buf, int bxsize) { int x, y; for (y = 0; y < pysize; y++) { for (x = 0; x < pxsize; x++) { vram[(py0 + y) * vxsize + (px0 + x)] = buf[y * bxsize + x]; } } return; }
harib02i:
P101 怎么才能让鼠标动起来？我们先来看看什么事GDT和IDT
这两个东西是CPU有关的设定（大家暂时不用深究什么是设定，先往下看）
接下来要用汇编语言（有回到汇编语言了）来对CPU做一些鼠标的设定
接下来笔者讲了操作系统分段的概念，关于分段、分页。学过操作系统的都应该知道，不再赘述
GDT：全局段号记录表，存放在内存中的。把需要查找的地址和相应的段号对应起来，便于寻址和查找；
寄存器GDTR用来存储该段内存的起始地址和有效的设定个数
IDT：中断记录表；中断号为0-255；每一个中断号对应一个函数调用，
这些函数就是用来处理操作系统中的中断的，中断发生后，调用通过IDT调用相应的中断函数即可
//bootpack.c节选 struct SEGMENT_DESCRIPTOR { //GDT的内容；8字节 short limit_low, base_low; char base_mid, access_right; char limit_high, base_high; }; struct GATE_DESCRIPTOR { //IDT的内容，8字节 short offset_low, selector; char dw_count, access_right; short offset_high; }; ................... void init_gdtidt(void) //GDT和IDT的初始化 { struct SEGMENT_DESCRIPTOR *gdt = (struct SEGMENT_DESCRIPTOR *) 0x00270000; struct GATE_DESCRIPTOR *idt = (struct GATE_DESCRIPTOR *) 0x0026f800; int i; /* GDT初始化 */ for (i = 0; i < 8192; i++) { //i每次加一；但是gdt指向8字节的结构体；结果地址增加了8 set_segmdesc(gdt + i, 0, 0, 0); //gdt*（地址）每次+8 } set_segmdesc(gdt + 1, 0xffffffff, 0x00000000, 0x4092); //段号为1；大小4G 表示CPU管理的全部内存 set_segmdesc(gdt + 2, 0x0007ffff, 0x00280000, 0x409a); //段号位2； 大小512K 为bootpack.hrb准备 load_gdtr(0xffff, 0x00270000); //GDT 0x270000-0x27ffff 借助汇编语言的力量给寄存器GDTR赋值 /* IDT初始化 */ for (i = 0; i < 256; i++) { //和上面一样 set_gatedesc(idt + i, 0, 0, 0); } //IDT 0x26f800-0x26ffff load_idtr(0x7ff, 0x0026f800); //向寄存器IDTR赋值 return; }