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Diffstat (limited to 'sos-code-article3/sos/main.c')
| -rw-r--r-- | sos-code-article3/sos/main.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/sos-code-article3/sos/main.c b/sos-code-article3/sos/main.c new file mode 100644 index 0000000..3cce935 --- /dev/null +++ b/sos-code-article3/sos/main.c @@ -0,0 +1,236 @@ +/* Copyright (C) 2004 The SOS Team + Copyright (C) 1999 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + USA. +*/ + +/* Include definitions of the multiboot standard */ +#include <bootstrap/multiboot.h> +#include <hwcore/idt.h> +#include <hwcore/gdt.h> +#include <hwcore/irq.h> +#include <hwcore/exception.h> +#include <hwcore/i8254.h> +#include <sos/list.h> +#include <sos/physmem.h> +#include <sos/klibc.h> +#include <sos/assert.h> +#include <drivers/x86_videomem.h> +#include <drivers/bochs.h> + + +/* Helper function to display each bits of a 32bits integer on the + screen as dark or light carrets */ +static void display_bits(unsigned char row, unsigned char col, + unsigned char attribute, + sos_ui32_t integer) +{ + int i; + /* Scan each bit of the integer, MSb first */ + for (i = 31 ; i >= 0 ; i--) + { + /* Test if bit i of 'integer' is set */ + int bit_i = (integer & (1 << i)); + /* Ascii 219 => dark carret, Ascii 177 => light carret */ + unsigned char ascii_code = bit_i?219:177; + sos_x86_videomem_putchar(row, col++, + attribute, + ascii_code); + } +} + + +/* Clock IRQ handler */ +static void clk_it(int intid) +{ + static sos_ui32_t clock_count = 0; + + display_bits(0, 48, + SOS_X86_VIDEO_FG_LTGREEN | SOS_X86_VIDEO_BG_BLUE, + clock_count); + clock_count++; + +} + +#define MY_PPAGE_NUM_INT 511 +struct my_ppage +{ + sos_ui32_t before[MY_PPAGE_NUM_INT]; + struct my_ppage *prev, *next; + sos_ui32_t after[MY_PPAGE_NUM_INT]; +}; /* sizeof() Must be <= 4kB */ + +static void test_physmem() +{ + /* We place the pages we did allocate here */ + struct my_ppage *ppage_list, *my_ppage; + sos_count_t num_alloc_ppages = 0, num_free_ppages = 0; + + ppage_list = NULL; + while ((my_ppage = (struct my_ppage*)sos_physmem_ref_physpage_new(FALSE)) + != NULL) + { + int i; + num_alloc_ppages++; + + /* Print the allocation status */ + sos_x86_videomem_printf(2, 0, + SOS_X86_VIDEO_FG_YELLOW + | SOS_X86_VIDEO_BG_BLUE, + "Could allocate %d pages ", + num_alloc_ppages); + + /* We fill this page with its address */ + for (i = 0 ; i < MY_PPAGE_NUM_INT ; i++) + my_ppage->before[i] = my_ppage->after[i] = (sos_ui32_t)my_ppage; + + /* We add this page at the tail of our list of ppages */ + list_add_tail(ppage_list, my_ppage); + } + + /* Now we release these pages in FIFO order */ + while ((my_ppage = list_pop_head(ppage_list)) != NULL) + { + /* We make sure this page was not overwritten by any unexpected + value */ + int i; + for (i = 0 ; i < MY_PPAGE_NUM_INT ; i++) + { + /* We don't get what we expect ! */ + if ((my_ppage->before[i] != (sos_ui32_t)my_ppage) + || (my_ppage->after[i] != (sos_ui32_t)my_ppage)) + { + /* STOP ! */ + sos_x86_videomem_putstring(20, 0, + SOS_X86_VIDEO_FG_LTRED + | SOS_X86_VIDEO_BG_BLUE, + "Page overwritten"); + return; + } + } + + /* Release the descriptor */ + if (sos_physmem_unref_physpage((sos_paddr_t)my_ppage) < 0) + { + /* STOP ! */ + sos_x86_videomem_putstring(20, 0, + SOS_X86_VIDEO_FG_LTRED + | SOS_X86_VIDEO_BG_BLUE, + "Cannot release page"); + return; + } + + /* Print the deallocation status */ + num_free_ppages ++; + sos_x86_videomem_printf(2, 0, + SOS_X86_VIDEO_FG_YELLOW + | SOS_X86_VIDEO_BG_BLUE, + "Could free %d pages ", + num_free_ppages); + } + + /* Print the overall stats */ + sos_x86_videomem_printf(2, 0, + SOS_X86_VIDEO_FG_LTGREEN + | SOS_X86_VIDEO_BG_BLUE, + "Could allocate %d bytes, could free %d bytes ", + num_alloc_ppages << SOS_PAGE_SHIFT, + num_free_ppages << SOS_PAGE_SHIFT); + + SOS_ASSERT_FATAL(num_alloc_ppages == num_free_ppages); +} + + +/* The C entry point of our operating system */ +void sos_main(unsigned long magic, unsigned long addr) +{ + unsigned i; + sos_paddr_t sos_kernel_core_base_paddr, sos_kernel_core_top_paddr; + + /* Grub sends us a structure, called multiboot_info_t with a lot of + precious informations about the system, see the multiboot + documentation for more information. */ + multiboot_info_t *mbi; + mbi = (multiboot_info_t *) addr; + + /* Setup bochs and console, and clear the console */ + sos_bochs_setup(); + + sos_x86_videomem_setup(); + sos_x86_videomem_cls(SOS_X86_VIDEO_BG_BLUE); + + /* Greetings from SOS */ + if (magic == MULTIBOOT_BOOTLOADER_MAGIC) + /* Loaded with Grub */ + sos_x86_videomem_printf(1, 0, + SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, + "Welcome From GRUB to %s%c RAM is %dMB (upper mem = 0x%x kB)", + "SOS", ',', + (unsigned)(mbi->mem_upper >> 10) + 1, + (unsigned)mbi->mem_upper); + else + /* Not loaded with grub */ + sos_x86_videomem_printf(1, 0, + SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, + "Welcome to SOS"); + + sos_bochs_putstring("Message in a bochs\n"); + + /* Setup CPU segmentation and IRQ subsystem */ + sos_gdt_setup(); + sos_idt_setup(); + + /* Setup SOS IRQs and exceptions subsystem */ + sos_exceptions_setup(); + sos_irq_setup(); + + /* Configure the timer so as to raise the IRQ0 at a 100Hz rate */ + sos_i8254_set_frequency(100); + + + /* We need a multiboot-compliant boot loader to get the size of the RAM */ + if (magic != MULTIBOOT_BOOTLOADER_MAGIC) + { + sos_x86_videomem_putstring(20, 0, + SOS_X86_VIDEO_FG_LTRED + | SOS_X86_VIDEO_BG_BLUE + | SOS_X86_VIDEO_FG_BLINKING, + "I'm not loaded with Grub !"); + /* STOP ! */ + for (;;) + continue; + } + + /* Binding some HW interrupts and exceptions to software routines */ + sos_irq_set_routine(SOS_IRQ_TIMER, + clk_it); + /* Enabling the HW interrupts here, this will make the timer HW + interrupt call our clk_it handler */ + asm volatile ("sti\n"); + /* Multiboot says: "The value returned for upper memory is maximally + the address of the first upper memory hole minus 1 megabyte.". It + also adds: "It is not guaranteed to be this value." aka "YMMV" ;) */ + sos_physmem_setup((mbi->mem_upper<<10) + (1<<20), + & sos_kernel_core_base_paddr, + & sos_kernel_core_top_paddr); + test_physmem(); + + /* An operatig system never ends */ + for (;;) + continue; + + return; +} |