From 54e7efbbd0e0c88d99bb6bddb82e9fc8d90eae50 Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Sun, 30 Nov 2014 19:58:32 +0100 Subject: Add debug output and a few elementary stdlib functions. --- kernel/Makefile | 19 ++++-- kernel/config.h | 27 ++++++++ kernel/include/dbglog.h | 7 +++ kernel/include/multiboot.h | 6 +- kernel/include/printf.h | 8 +++ kernel/include/stdlib.h | 7 +++ kernel/include/sys.h | 14 +++++ kernel/l0/dbglog.c | 151 +++++++++++++++++++++++++++++++++++++++++++++ kernel/l0/kmain.c | 132 +++------------------------------------ kernel/l0/sys.c | 44 +++++++++++++ kernel/lib/printf.c | 105 +++++++++++++++++++++++++++++++ kernel/lib/stdlib.c | 8 +++ 12 files changed, 398 insertions(+), 130 deletions(-) create mode 100644 kernel/config.h create mode 100644 kernel/include/dbglog.h create mode 100644 kernel/include/printf.h create mode 100644 kernel/include/stdlib.h create mode 100644 kernel/include/sys.h create mode 100644 kernel/l0/dbglog.c create mode 100644 kernel/l0/sys.c create mode 100644 kernel/lib/printf.c create mode 100644 kernel/lib/stdlib.c diff --git a/kernel/Makefile b/kernel/Makefile index 7a29c9e..6e973dd 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -3,15 +3,18 @@ AS = nasm ASFLAGS = -felf CC = i586-elf-gcc -CFLAGS = -ffreestanding -O2 -std=gnu99 -Wall -Wextra -I ./include +CFLAGS = -ffreestanding -O2 -std=gnu99 -Wall -Wextra -I . -I ./include +# CXX = i586-elf-g++ +# CXFLAGS = -ffreestanding -O2 -Wall -Wextra -I . -I ./include -fno-exceptions -fno-rtti LD = i586-elf-gcc LDFLAGS = -T linker.ld -ffreestanding -O2 -nostdlib -lgcc -OBJ = l0/loader.o l0/kmain.o +OBJ = lib/stdlib.o lib/printf.o l0/loader.o l0/kmain.o l0/dbglog.o l0/sys.o +OUT = kernel.bin -all: kernel.bin +all: $(OUT) -kernel.bin: $(OBJ) +$(OUT): $(OBJ) $(LD) $(LDFLAGS) -o $@ $^ %.o: %.s @@ -19,3 +22,11 @@ kernel.bin: $(OBJ) %.o: %.c $(CC) -c $< -o $@ $(CFLAGS) + +# %.o: %.cpp +# $(CXX) -c $< -o $@ $(CXFLAGS) + +clean: + rm */*.o || true +mrproper: clean + rm $(OUT) diff --git a/kernel/config.h b/kernel/config.h new file mode 100644 index 0000000..5ea242e --- /dev/null +++ b/kernel/config.h @@ -0,0 +1,27 @@ +#if !defined(__cplusplus) +#include +#endif + +#include +#include + +#if defined(__linux__) +#error "This kernel needs to be compiled with a cross-compiler." +#endif + +#if !defined(__i386__) +#error "This kernel needs to be compiled with a ix86-elf compiler" +#endif + + +extern char k_highhalf_addr; // defined in linker script : 0xC0000000 +#define K_HIGHHALF_ADDR ((void*)&k_highhalf_addr) + +#define OS_NAME "Macroscope" +#define OS_VERSION "0.0.1" + +// Comment to disable either form of debug log output +#define DBGLOG_TO_SERIAL +#define DBGLOG_TO_SCREEN + + diff --git a/kernel/include/dbglog.h b/kernel/include/dbglog.h new file mode 100644 index 0000000..c8904c6 --- /dev/null +++ b/kernel/include/dbglog.h @@ -0,0 +1,7 @@ +#pragma once + +#include + +void dbglog_setup(); +void dbg_print(const char* str); +void dbg_printf(const char* format, ...); diff --git a/kernel/include/multiboot.h b/kernel/include/multiboot.h index 908274c..8fd9dee 100644 --- a/kernel/include/multiboot.h +++ b/kernel/include/multiboot.h @@ -1,5 +1,5 @@ -#ifndef HDR_MULTIBOOT -#define HDR_MULTIBOOT +#pragma once + #define MULTIBOOT_HEADER_MAGIC 0x1BADB002 #define MULTIBOOT_BOOTLOADER_MAGIC 0x2BADB002 @@ -60,5 +60,3 @@ struct memory_map_t { unsigned long type; }; -#endif - diff --git a/kernel/include/printf.h b/kernel/include/printf.h new file mode 100644 index 0000000..4569827 --- /dev/null +++ b/kernel/include/printf.h @@ -0,0 +1,8 @@ +#pragma once + +#include +#include + +int snprintf(char* s, size_t n, const char* format, ...); +int vsnprintf(char* s, size_t n, const char* format, va_list arg); + diff --git a/kernel/include/stdlib.h b/kernel/include/stdlib.h new file mode 100644 index 0000000..601e7c4 --- /dev/null +++ b/kernel/include/stdlib.h @@ -0,0 +1,7 @@ +#pragma once + +#include +#include + +size_t strlen(const char*); + diff --git a/kernel/include/sys.h b/kernel/include/sys.h new file mode 100644 index 0000000..b76ca26 --- /dev/null +++ b/kernel/include/sys.h @@ -0,0 +1,14 @@ +#pragma once + +#include + +void outb(uint16_t port, uint8_t value); +void outw(uint16_t port, uint16_t value); +uint8_t inb(uint16_t port); +uint16_t inw(uint16_t port); + + +#define PANIC(s) panic(s, __FILE__, __LINE__); +#define ASSERT(s) { if (!(s)) panic_assert(#s, __FILE__, __LINE__); } +void panic(const char* message, const char* file, int line); +void panic_assert(const char* assertion, const char* file, int line); diff --git a/kernel/l0/dbglog.c b/kernel/l0/dbglog.c new file mode 100644 index 0000000..0285002 --- /dev/null +++ b/kernel/l0/dbglog.c @@ -0,0 +1,151 @@ +#include +#include +#include +#include +#include +#include + +// ================================================================== + +#ifdef DBGLOG_TO_SCREEN + +static const size_t VGA_WIDTH = 80; +static const size_t VGA_HEIGHT = 25; + +static uint8_t vga_color = 7; +static uint16_t* vga_buffer = 0; +static uint16_t vga_row = 0, vga_column = 0; + +static uint16_t make_vgaentry(char c, uint8_t color) { + uint16_t c16 = c; + uint16_t color16 = color; + return c16 | color16 << 8; +} + +static void vga_putentryat(char c, uint8_t color, size_t x, size_t y) { + const size_t index = y * VGA_WIDTH + x; + vga_buffer[index] = make_vgaentry(c, color); +} + +static void vga_update_cursor() { + uint16_t cursor_location = vga_row * 80 + vga_column; + outb(0x3D4, 14); //Sending high cursor byte + outb(0x3D5, cursor_location >> 8); + outb(0x3D4, 15); //Sending high cursor byte + outb(0x3D5, cursor_location); +} + +static void vga_init() { + vga_row = 0; + vga_column = 0; + vga_buffer = (uint16_t*) (&k_highhalf_addr + 0xB8000); + + for (size_t y = 0; y < VGA_HEIGHT; y++) { + for (size_t x = 0; x < VGA_WIDTH; x++) { + vga_putentryat(' ', vga_color, x, y); + } + } + + vga_update_cursor(); +} + +static void vga_scroll() { + for (size_t i = 0; i < VGA_WIDTH * (VGA_HEIGHT - 1); i++) { + vga_buffer[i] = vga_buffer[i + VGA_WIDTH]; + } + for (size_t x = 0; x < VGA_WIDTH; x++) { + vga_putentryat(' ', vga_color, x, VGA_HEIGHT - 1); + } + vga_row--; +} + +static void vga_newline() { + vga_column = 0; + if (++vga_row == VGA_HEIGHT) { + vga_scroll(); + } +} + +static void vga_putc(char c) { + if (c == '\n') { + vga_newline(); + } else if (c == '\t') { + vga_putc(' '); + while (vga_column % 4 != 0) vga_putc(' '); + } else { + vga_putentryat(c, vga_color, vga_column, vga_row); + if (++vga_column == VGA_WIDTH) { + vga_newline(); + } + } +} + +static void vga_puts(const char* data) { + size_t datalen = strlen(data); + for (size_t i = 0; i < datalen; i++) + vga_putc(data[i]); + + vga_update_cursor(); +} + +#endif // DBGLOG_TO_SCREEN + +// ================================================================== + +#ifdef DBGLOG_TO_SERIAL + +#define SER_PORT 0x3F8 // COM1 + +static void serial_init() { + outb(SER_PORT + 1, 0x00); // disable interrupts + outb(SER_PORT + 3, 0x80); // set baud rate + outb(SER_PORT + 0, 0x03); // set divisor to 3 (38400 baud) + outb(SER_PORT + 1, 0x00); + outb(SER_PORT + 3, 0x03); // 8 bits, no parity, one stop bit + outb(SER_PORT + 2, 0xC7); // enable FIFO, clear them, with 14-byte threshold +} + +static void serial_putc(const char c) { + while (!(inb(SER_PORT + 5) & 0x20)); + outb(SER_PORT, c); +} + +static void serial_puts(const char *c) { + while (*c) { + serial_putc(*c); + c++; + } +} + +#endif // DBGLOG_TO_SERIAL + +// ================================================================== + +void dbglog_setup() { +#ifdef DBGLOG_TO_SCREEN + vga_init(); +#endif +#ifdef DBGLOG_TO_SERIAL + serial_init(); +#endif +} + +void dbg_print(const char* str) { +#ifdef DBGLOG_TO_SCREEN + vga_puts(str); +#endif +#ifdef DBGLOG_TO_SERIAL + serial_puts(str); +#endif +} + +void dbg_printf(const char* fmt, ...) { + va_list ap; + char buffer[256]; + + va_start(ap, fmt); + vsnprintf(buffer, 256, fmt, ap); + va_end(ap); + + dbg_print(buffer); +} diff --git a/kernel/l0/kmain.c b/kernel/l0/kmain.c index 9139856..74945e4 100644 --- a/kernel/l0/kmain.c +++ b/kernel/l0/kmain.c @@ -1,126 +1,14 @@ -#if !defined(__cplusplus) -#include /* C doesn't have booleans by default. */ -#endif -#include -#include +#include +#include +#include +#include -/* Check if the compiler thinks if we are targeting the wrong operating system. */ -#if defined(__linux__) -#error "You are not using a cross-compiler, you will most certainly run into trouble" -#endif - -/* This tutorial will only work for the 32-bit ix86 targets. */ -#if !defined(__i386__) -#error "This tutorial needs to be compiled with a ix86-elf compiler" -#endif +void kmain(struct multiboot_info_t *mbd, int32_t mb_magic) { + dbglog_setup(); -#include "multiboot.h" - -extern void k_highhalf_addr; + dbg_printf("Hello, kernel World!\n"); + dbg_printf("This is %s, version %s.\n", OS_NAME, OS_VERSION); -/* Hardware text mode color constants. */ -enum vga_color -{ - COLOR_BLACK = 0, - COLOR_BLUE = 1, - COLOR_GREEN = 2, - COLOR_CYAN = 3, - COLOR_RED = 4, - COLOR_MAGENTA = 5, - COLOR_BROWN = 6, - COLOR_LIGHT_GREY = 7, - COLOR_DARK_GREY = 8, - COLOR_LIGHT_BLUE = 9, - COLOR_LIGHT_GREEN = 10, - COLOR_LIGHT_CYAN = 11, - COLOR_LIGHT_RED = 12, - COLOR_LIGHT_MAGENTA = 13, - COLOR_LIGHT_BROWN = 14, - COLOR_WHITE = 15, -}; - -uint8_t make_color(enum vga_color fg, enum vga_color bg) -{ - return fg | bg << 4; -} - -uint16_t make_vgaentry(char c, uint8_t color) -{ - uint16_t c16 = c; - uint16_t color16 = color; - return c16 | color16 << 8; -} - -size_t strlen(const char* str) -{ - size_t ret = 0; - while ( str[ret] != 0 ) - ret++; - return ret; -} - -static const size_t VGA_WIDTH = 80; -static const size_t VGA_HEIGHT = 25; - -size_t terminal_row; -size_t terminal_column; -uint8_t terminal_color; -uint16_t* terminal_buffer; - -void terminal_initialize() -{ - terminal_row = 0; - terminal_column = 0; - terminal_color = make_color(COLOR_LIGHT_GREY, COLOR_BLACK); - terminal_buffer = (uint16_t*) (&k_highhalf_addr + 0xB8000); - for ( size_t y = 0; y < VGA_HEIGHT; y++ ) - { - for ( size_t x = 0; x < VGA_WIDTH; x++ ) - { - const size_t index = y * VGA_WIDTH + x; - terminal_buffer[index] = make_vgaentry(' ', terminal_color); - } - } -} - -void terminal_setcolor(uint8_t color) -{ - terminal_color = color; -} - -void terminal_putentryat(char c, uint8_t color, size_t x, size_t y) -{ - const size_t index = y * VGA_WIDTH + x; - terminal_buffer[index] = make_vgaentry(c, color); -} - -void terminal_putchar(char c) -{ - terminal_putentryat(c, terminal_color, terminal_column, terminal_row); - if ( ++terminal_column == VGA_WIDTH ) - { - terminal_column = 0; - if ( ++terminal_row == VGA_HEIGHT ) - { - terminal_row = 0; - } - } -} - -void terminal_writestring(const char* data) -{ - size_t datalen = strlen(data); - for ( size_t i = 0; i < datalen; i++ ) - terminal_putchar(data[i]); -} - -#if defined(__cplusplus) -extern "C" /* Use C linkage for kernel_main. */ -#endif -void kmain(struct multiboot_info_t *mbd, int32_t mb_magic) -{ - terminal_initialize(); - /* Since there is no support for newlines in terminal_putchar yet, \n will - produce some VGA specific character instead. This is normal. */ - terminal_writestring("Hello, kernel World!\n"); + PANIC("Reached kmain end! Falling off the edge."); } + diff --git a/kernel/l0/sys.c b/kernel/l0/sys.c new file mode 100644 index 0000000..f6a9900 --- /dev/null +++ b/kernel/l0/sys.c @@ -0,0 +1,44 @@ +#include +#include + + +// C wrappers for inb/outb/inw/outw + +void outb(uint16_t port, uint8_t value) { + asm volatile("outb %1, %0" : : "dN"(port), "a"(value)); +} + +void outw(uint16_t port, uint16_t value) { + asm volatile("outw %1, %0" : : "dN"(port), "a"(value)); +} + +uint8_t inb(uint16_t port) { + uint8_t ret; + asm volatile("inb %1, %0" : "=a"(ret) : "dN"(port)); + return ret; +} + +uint16_t inw(uint16_t port) { + uint16_t ret; + asm volatile("inw %1, %0" : "=a"(ret) : "dN"(port)); + return ret; +} + +// Kernel panic and kernel assert failure + +static void panic_do(const char* type, const char *msg, const char* file, int line) { + asm volatile("cli;"); + dbg_printf("/\n| %s:\t%s\n", type, msg); + dbg_printf("| File: \t%s:%i\n", file, line); + dbg_printf("| System halted -_-'\n"); + dbg_printf("\\---------------------------------------------------------/"); + asm volatile("hlt"); +} + +void panic(const char* message, const char* file, int line) { + panic_do("PANIC", message, file, line); +} + +void panic_assert(const char* assertion, const char* file, int line) { + panic_do("ASSERT FAILED", assertion, file, line); +} diff --git a/kernel/lib/printf.c b/kernel/lib/printf.c new file mode 100644 index 0000000..fdf474d --- /dev/null +++ b/kernel/lib/printf.c @@ -0,0 +1,105 @@ +#include +#include + +int snprintf(char * buff, size_t len, const char *format, ...) { + va_list ap; + + va_start(ap, format); + len = vsnprintf(buff, len, format, ap); + va_end(ap); + + return len; +} + +int vsnprintf(char *buff, size_t len, const char* format, va_list ap){ + size_t i, result; + + if (!buff || !format) + return -1; + +#define PUTCHAR(thechar) \ + do { \ + if (result < len-1) \ + *buff++ = (thechar); \ + result++; \ + } while (0) + + result = 0; + for(i = 0; format[i] != '\0' ; i++) { + if (format[i] == '%') { + i++; + switch(format[i]) { + case '%': + PUTCHAR('%'); + break; + + case 'i':; + case 'd': { + int integer = va_arg(ap,int); + int cpt2 = 0; + char buff_int[16]; + + if (integer<0) + PUTCHAR('-'); + + do { + int m10 = integer%10; + m10 = (m10 < 0)? -m10:m10; + buff_int[cpt2++] = (char)('0'+ m10); + integer = integer/10; + } while(integer != 0); + + for(cpt2 = cpt2 - 1; cpt2 >= 0; cpt2--) + PUTCHAR(buff_int[cpt2]); + + break; + } + case 'c': { + int value = va_arg(ap,int); + PUTCHAR((char)value); + break; + } + case 's': { + char *string = va_arg(ap,char *); + if (!string) + string = "(null)"; + for(; *string != '\0' ; string++) + PUTCHAR(*string); + break; + } + case 'x': { + unsigned int hexa = va_arg(ap,int); + unsigned int nb; + int j, had_nonzero = 0; + for(j = 0; j < 8; j++) + { + nb = (unsigned int)(hexa << (j*4)); + nb = (nb >> 28) & 0xf; + // Skip the leading zeros + if (nb == 0) { + if (had_nonzero) + PUTCHAR('0'); + } else { + had_nonzero = 1; + if (nb < 10) + PUTCHAR('0'+nb); + else + PUTCHAR('a'+(nb-10)); + } + } + if (!had_nonzero) + PUTCHAR('0'); + break; + } + default: + PUTCHAR('%'); + PUTCHAR(format[i]); + } + } else { + PUTCHAR(format[i]); + } + } + + *buff = '\0'; + return result; +} diff --git a/kernel/lib/stdlib.c b/kernel/lib/stdlib.c new file mode 100644 index 0000000..6710da2 --- /dev/null +++ b/kernel/lib/stdlib.c @@ -0,0 +1,8 @@ +#include + +size_t strlen(const char* str) { + size_t ret = 0; + while (str[ret] != 0) + ret++; + return ret; +} -- cgit v1.2.3