// Initialize the GDT
void gdt_init() {
// Tasks setup
for (int i = 0; i < tasks_nb; i++)
setup_task(i);
// Set the address and the size of the GDT in the pointer
gdt_ptr.limit = sizeof(gdt);
gdt_ptr.base = (uint32_t) &gdt;
// Initializing the three segment descriptors in the GDT : NULL, code segment, data segment
gdt[0] = null_segment();
gdt[1] = code_segment(0, 1048575, DPL_KERNEL);
gdt[2] = data_segment(0, 1048575, DPL_KERNEL);
// gdt[3] : entry for initial kernel TSS (CPU state of first task saved there)
static uint8_t initial_tss_kernel_stack[65536]; // 64KB of stack
static tss_t initial_tss;
gdt[3] = gdt_make_tss(&initial_tss, DPL_KERNEL);
memset(&initial_tss, 0, sizeof(tss_t));
initial_tss.ss0 = GDT_KERNEL_DATA_SELECTOR;
initial_tss.esp0 = ((uint32_t) initial_tss_kernel_stack) + sizeof(initial_tss_kernel_stack);
// Load the GDT
gdt_flush(&gdt_ptr);
// Load the task register to point to the initial TSS selector
load_task_register(gdt_entry_to_selector(&gdt[3]));
// Confirmation message
set_text_color(LIGHT_GREEN);
printf("OK\n");
set_text_color(WHITE);
}
/* Note: this is not the first ui function to be called.
* Display modes are registered prior to this
* function being called.
* In fact, all display modes must be registered
* before this function is called. */
task_t *ui_task_create(u8 start_mode)
{
#if 0
/* These modes are not enabled by default */
set_mode_disable_bit_cb(MODE_OILPRES);
set_mode_disable_bit_cb(MODE_EGT_INSTANT);
set_mode_disable_bit_cb(MODE_EGT_PEAK);
#endif
if (start_mode == MODE_MODE_SELECT)
{
current.mnum = MODE_MODE_SELECT;
display_modes[MODE_MODE_SELECT].displayfunc = mode_select_display_func;
ui_in_config_flag = 1;
do_config_word(0);
}
else
{
load_configuration_words();
if (start_mode == MODE_ATMOSPHERIC)
{
/* Do not validate if we are starting up in atmospheric mode.
* Even if it is disabled it should be displayed after measurement. */
current.mnum = start_mode;
}
else
{
current.mnum = validate_mode(start_mode);
}
}
ui_display_callback(NULL);
return setup_task(&ui_taskinfo, TASK_ID_UI, ui_task, ui_mailbox_buf, sizeof(ui_mailbox_buf));
}
task_t *i2c_task_create()
{
/* Enable internal pullups for SDA and SCL */
DDRD &= (~3); /* D0/D1 inputs (this is overriddedn with TWEN) */
PORTD |= 3; /* D0/D1 pulled up */
TWSR = 0; /* no prescaler */
TWBR = 72; /* = 100kHz @ 16MHz core */
return setup_task(&i2c_taskinfo, TASK_ID_I2C, i2c_task,
i2c_mailbox_buf, sizeof(i2c_mailbox_buf));
}
/* called by main */
task_t* comms_task_create()
{
/* Configure the baud rate.
* Should move this to comms_avr.c */
UBRR0L = (uint8_t)(CPU_FREQ/(UART_BAUD_RATE*16L)-1);
UBRR0H = (CPU_FREQ/(UART_BAUD_RATE*16L)-1) >> 8;
UCSR0A = 0x0;
UCSR0C = _BV(UCSZ01)|_BV(UCSZ00);
UCSR0B = _BV(TXEN0)|_BV(RXEN0)|_BV(RXCIE0);
return setup_task(&comms_taskinfo, TASK_ID_COMMS, comms_task,
comms_mailbox_buf, sizeof(comms_mailbox_buf));
}
task_t *onewire_task_create()
{
return setup_task(&ow_taskinfo, TASK_ID_ONEWIRE, ow_task, ow_mailbox_buf, sizeof(ow_mailbox_buf));
}
void start_kernel(void)
{
char str[] = "C FUNCTION START!";
/*
* ARCHITECTURE DEPENDENT INITIALIZATIONS
*/
/* screen - message display */
init_screen();
caos_printf("%s\n", str);
/* memory manager */
setup_memory();
/* exception & interrupt */
init_idt();
set_idtr();
/* device & IRQ */
init_char_dev();
keyboard_init();
init_timer();
/* scheduling */
init_scheduler();
/* task management */
setup_task();
init_cpu_tss();
/* after task setup, start scheduler */
start_scheduler();
/*************************************************/
/*
* ARCHITECTURE INDEPENDENT PROCESSING
*/
if (create_task(init, "init") < 0)
caos_printf("Create Init fail..\n");
if (create_task(user1, "user1") < 0)
caos_printf("Create user1 fail..\n");
if (create_task(user2, "user2") < 0)
caos_printf("Create user2 fail..\n");
caos_printf("CaOS KERNEL END!!\n");
/* execute user mode task */
start_init();
while (1);
}
