tianole/kernel/main.c

84 lines
2.2 KiB
C

#include <stdint.h>
#include "tianole/boot_info.h"
static inline void debug_putc(char ch) {
__asm__ volatile("outb %0, $0xe9" : : "a"(ch));
}
static void debug_puts(const char *text) {
while (*text != '\0') {
if (*text == '\n') {
debug_putc('\r');
}
debug_putc(*text++);
}
}
static void debug_put_u64_decimal(uint64_t value) {
char digits[20];
uint32_t index = 0;
if (value == 0) {
debug_putc('0');
return;
}
while (value != 0) {
digits[index++] = (char)('0' + (value % 10));
value /= 10;
}
while (index != 0) {
debug_putc(digits[--index]);
}
}
static void log_memory_map_summary(const tianole_boot_info_t *boot_info) {
uint64_t offset;
uint64_t descriptors = 0;
uint64_t conventional_pages = 0;
if (boot_info == 0 || boot_info->memory_map == 0 || boot_info->memory_descriptor_size == 0) {
debug_puts("memory map metadata missing\n");
return;
}
for (offset = 0; offset + sizeof(tianole_efi_memory_descriptor_t) <= boot_info->memory_map_size;
offset += boot_info->memory_descriptor_size) {
const tianole_efi_memory_descriptor_t *descriptor =
(const tianole_efi_memory_descriptor_t *)(uintptr_t)(boot_info->memory_map + offset);
descriptors++;
if (descriptor->type == TIANOLE_EFI_MEMORY_TYPE_CONVENTIONAL) {
conventional_pages += descriptor->number_of_pages;
}
}
debug_puts("memory map descriptors=");
debug_put_u64_decimal(descriptors);
debug_puts("\n");
debug_puts("conventional memory pages=");
debug_put_u64_decimal(conventional_pages);
debug_puts("\n");
}
void kernel_main(const tianole_boot_info_t *boot_info) {
debug_puts("kernel_main entered\n");
if (boot_info != 0 && boot_info->version == TIANOLE_BOOT_INFO_VERSION) {
debug_puts("boot_info.version ok\n");
} else {
debug_puts("boot_info.version invalid\n");
}
if (boot_info != 0 && (boot_info->boot_flags & TIANOLE_BOOT_FLAG_BOOT_SERVICES_ACTIVE) != 0) {
debug_puts("boot services still active\n");
}
log_memory_map_summary(boot_info);
for (;;) {
__asm__ volatile("hlt");
}
}