selfmade-os
changeset 1:42ba76f77035 tip
the kernel with output and mem alloc
| author | meillo@marmaro.de |
|---|---|
| date | Sun, 01 Nov 2009 23:50:51 +0100 |
| parents | 99db6262c157 |
| children | |
| files | io.c io.h kernel.c makefile mem.c mem.h |
| diffstat | 6 files changed, 301 insertions(+), 0 deletions(-) [+] |
line diff
1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/io.c Sun Nov 01 23:50:51 2009 +0100 1.3 @@ -0,0 +1,151 @@ 1.4 +#include <stdarg.h> 1.5 +#include "io.h" 1.6 + 1.7 +void prints(const char* str); 1.8 + 1.9 +static unsigned short* vidmem = (unsigned short*) 0xb8000; 1.10 +static unsigned short color = 0x0700; 1.11 +static int pos = 0; 1.12 + 1.13 +void 1.14 +cls(void) 1.15 +{ 1.16 + unsigned short* v; 1.17 + 1.18 + for (v = vidmem; v < vidmem+(80*25); v++) { 1.19 + *v = 0; 1.20 + } 1.21 + pos = 0; 1.22 +} 1.23 + 1.24 + 1.25 +void 1.26 +setcolor(int fg, int bg) 1.27 +{ 1.28 + color = (char) ((fg<<2) & (bg<<3)); 1.29 +} 1.30 + 1.31 +void 1.32 +setpos(int line, int col) 1.33 +{ 1.34 + pos = line * 80 + col; 1.35 +} 1.36 + 1.37 +void 1.38 +relpos(int move) 1.39 +{ 1.40 + pos += move; 1.41 +} 1.42 + 1.43 + 1.44 +void 1.45 +printp(unsigned int n) 1.46 +{ 1.47 + int i, h; 1.48 + char str[11]; 1.49 + //int n = (int) p; 1.50 + 1.51 + str[0] = '0'; 1.52 + str[1] = 'x'; 1.53 + str[10] = '\0'; 1.54 + for (i=9; i>1; i--) { 1.55 + h = n % 16; 1.56 + str[i] = ('0' + h); 1.57 + if (h > 9) { 1.58 + str[i] += 'a' - '9' - 1; 1.59 + } 1.60 + n /= 16; 1.61 + } 1.62 + prints(str); 1.63 +} 1.64 + 1.65 + 1.66 + 1.67 + 1.68 +void 1.69 +printc(char c) 1.70 +{ 1.71 + putchar(c); 1.72 +} 1.73 + 1.74 +void 1.75 +prints(const char* str) 1.76 +{ 1.77 + const char* c; 1.78 + 1.79 + for (c = str; *c; c++) { 1.80 + printc(*c); 1.81 + } 1.82 +} 1.83 + 1.84 +void 1.85 +printd(int n) 1.86 +{ 1.87 + int i; 1.88 + char str[32]; 1.89 + 1.90 + str[31] = '\0'; 1.91 + for (i=30; i>0; i--) { 1.92 + str[i] = ('0' + n%10); 1.93 + if (n == 0) { 1.94 + i++; 1.95 + break; 1.96 + } 1.97 + n /= 10; 1.98 + } 1.99 + prints(&str[i]); 1.100 +} 1.101 + 1.102 + 1.103 +int 1.104 +putchar(int c) 1.105 +{ 1.106 + if (c == '\n') { 1.107 + pos = ((pos/80)+1) * 80; 1.108 + } else { 1.109 + vidmem[pos++] = (unsigned short)c | color; 1.110 + } 1.111 + return (unsigned char)c; 1.112 +} 1.113 + 1.114 +int 1.115 +puts(const char* s) 1.116 +{ 1.117 + prints(s); 1.118 + putchar('\n'); 1.119 + return 1; 1.120 +} 1.121 + 1.122 +int 1.123 +printf(const char* fmt, ...) 1.124 +{ 1.125 + va_list ap; 1.126 + int i; 1.127 + 1.128 + va_start(ap, fmt); 1.129 + for (i=0; fmt[i]; i++) { 1.130 + if (fmt[i] != '%') { 1.131 + printc(fmt[i]); 1.132 + continue; 1.133 + } 1.134 + switch (fmt[++i]) { 1.135 + case '%': 1.136 + printc('%'); 1.137 + break; 1.138 + case 'c': 1.139 + printc((char)va_arg(ap, int)); 1.140 + break; 1.141 + case 's': 1.142 + prints(va_arg(ap, char*)); 1.143 + break; 1.144 + case 'd': 1.145 + printd(va_arg(ap, int)); 1.146 + break; 1.147 + case 'p': 1.148 + printp(va_arg(ap, unsigned int)); 1.149 + break; 1.150 + } 1.151 + } 1.152 + va_end(ap); 1.153 + return 0; 1.154 +}
2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 2.2 +++ b/io.h Sun Nov 01 23:50:51 2009 +0100 2.3 @@ -0,0 +1,9 @@ 2.4 + 2.5 +void cls(void); 2.6 +void setcolor(int fg, int bg); 2.7 +void setpos(int line, int col); 2.8 +void relpos(int move); 2.9 + 2.10 +int putchar(int c); 2.11 +int puts(const char* s); 2.12 +int printf(const char* fmt, ...);
3.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 3.2 +++ b/kernel.c Sun Nov 01 23:50:51 2009 +0100 3.3 @@ -0,0 +1,31 @@ 3.4 +/* markus schnalke <meillo@marmaro.de> */ 3.5 + 3.6 +#include "io.h" 3.7 +#include "mem.h" 3.8 + 3.9 +void 3.10 +kmain(void) 3.11 +{ 3.12 + unsigned char* p; 3.13 + 3.14 + cls(); 3.15 + printf("OS says: Hi!\n\n"); 3.16 + 3.17 + initmem(0x00400000); /* heap starts at 4MB */ 3.18 + 3.19 + printf("init done\n"); 3.20 + printf("\n"); 3.21 + 3.22 + p = malloc(28); 3.23 + printf("allocated %d bytes at %p\n", 28, p); 3.24 + p = malloc(15); 3.25 + printf("allocated %d bytes at %p\n", 15, p); 3.26 + 3.27 + printf("aa %d bb %c cc %s\n", 5, '@', "hallo"); 3.28 + printf("minmem: %p\n", 0x00400000); 3.29 + 3.30 + setpos(24, 0); 3.31 + printf("loop\n"); 3.32 + while (1) { 3.33 + } 3.34 +}
4.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 4.2 +++ b/makefile Sun Nov 01 23:50:51 2009 +0100 4.3 @@ -0,0 +1,28 @@ 4.4 + 4.5 +CC = i386-elf-gcc 4.6 +CFLAGS = -Wall -Wextra -nostdlib -nostartfiles -nodefaultlibs 4.7 + 4.8 +LD = i386-elf-ld 4.9 +LDFLAGS = -T linker.ld 4.10 + 4.11 +OBJ = loader.o kernel.o io.o mem.o 4.12 + 4.13 +qemu: os.iso 4.14 + qemu -m 16 -boot cd -cdrom os.iso 4.15 + 4.16 +os.iso: kernel 4.17 + cp kernel os-isofiles/boot/kernel 4.18 + genisoimage -R -b boot/grub/stage2_eltorito -no-emul-boot -boot-load-size 4 -boot-info-table -o os.iso os-isofiles 4.19 + 4.20 +loader.o: loader.s 4.21 + yasm -f elf -o loader.o loader.s 4.22 + 4.23 +kernel: linker.ld $(OBJ) 4.24 + i386-elf-ld -T linker.ld -o kernel $(OBJ) 4.25 + 4.26 +clean: 4.27 + rm -f *.o 4.28 + rm -f kernel 4.29 + 4.30 +distclean: clean 4.31 + rm -f os.iso
5.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 5.2 +++ b/mem.c Sun Nov 01 23:50:51 2009 +0100 5.3 @@ -0,0 +1,74 @@ 5.4 +#include "mem.h" 5.5 +#include "io.h" 5.6 + 5.7 + 5.8 +void 5.9 +initmem(unsigned int memstart) 5.10 +{ 5.11 + unsigned int* p; 5.12 + int step = 2*1024*1024; 5.13 + unsigned int* zero = 0x0; 5.14 + 5.15 + 5.16 + minmem = (unsigned char*)memstart; 5.17 + 5.18 + /* disable cache */ 5.19 + __asm__ __volatile__ ( 5.20 + "movl %cr0, %eax\n\t" 5.21 + "movl $0x60000000, %ebx\n\t" 5.22 + "orl %ebx, %eax\n\t" 5.23 + "movl %eax, %cr0" 5.24 + ); 5.25 + 5.26 + /* test mem size */ 5.27 + p = (unsigned int*) ((unsigned int)minmem/sizeof(char)); 5.28 + do { 5.29 + p += step; 5.30 + *p = 0xf0f0f0f0; 5.31 + } while (*p == 0xf0f0f0f0); 5.32 + maxmem = (unsigned char*)p; 5.33 + 5.34 + /* test mem mirroring */ 5.35 + p = 0; 5.36 + *p = 0; 5.37 + p++; 5.38 + while (p < (unsigned int*)minmem) { 5.39 + p = (unsigned int*) ((unsigned int)p * 2); 5.40 + } 5.41 + while (p < (unsigned int*)maxmem) { 5.42 + *p = 0xf0f0f0f0; 5.43 + if (*zero == 0xf0f0f0f0) { 5.44 + maxmem = (unsigned char*)p; 5.45 + break; 5.46 + } 5.47 + p = (unsigned int*) ((unsigned int)p * 2); 5.48 + } 5.49 + 5.50 + /* enable cache again */ 5.51 + __asm__ __volatile__ ( 5.52 + "movl %cr0, %eax\n\t" 5.53 + "movl $0x60000000, %ebx \n\t" 5.54 + "negl %ebx\n\t" 5.55 + "andl %ebx, %eax\n\t" 5.56 + "movl %eax, %cr0" 5.57 + ); 5.58 + 5.59 + /* min, max */ 5.60 + printf("mem: start=%p end=%p size=%p\n", minmem, maxmem, (void*)(maxmem-minmem)); 5.61 + 5.62 + /* init heap */ 5.63 + newp = minmem; 5.64 +} 5.65 + 5.66 + 5.67 +void* 5.68 +malloc(unsigned int size) 5.69 +{ 5.70 + if (newp + size > maxmem) { 5.71 + printf("Fatal error: memory exhausted!\n"); 5.72 + while (1) { 5.73 + } 5.74 + } 5.75 + newp += size; 5.76 + return newp - size; 5.77 +}