#include <stdint.h>
#include <stddef.h>
#include <stdarg.h>
#include <uchar.h>

#define PAGE_SIZE 4096

#define nelem(arr) (sizeof(arr)/sizeof(*(arr)))

struct framebuffer
{
	void *addr;
	uint64_t width;
	uint64_t height;
	uint64_t pitch;
};

struct memmap
{
	uintptr_t start;
	uint64_t size;
};

struct ioapic_info
{
	uint32_t base;
	uint32_t interrupt_base;
};

struct boot_info
{
	struct framebuffer framebuffer;
	struct ioapic_info ioapic;
	uint64_t memmap_count;
	struct memmap *memmaps;
	uint64_t physbase;
	uint64_t rsdp;
};

struct cpu_regs
{
	/* Keep this in sync with dump_regs in nasty.S */
	uint64_t rax;
	uint64_t rbx;
	uint64_t rcx;
	uint64_t rdx;
	uint64_t rsi;
	uint64_t rdi;
	uint64_t rsp;
	uint64_t rbp;
	uint64_t r8;
	uint64_t r9;
	uint64_t r10;
	uint64_t r11;
	uint64_t r12;
	uint64_t r13;
	uint64_t r14;
	uint64_t r15;
	uint64_t rip;
	uint64_t rflags;
	uint64_t cr0;
	uint64_t cr2;
	uint64_t cr3;
	uint64_t cr4;
	uint64_t cr8;
	uint16_t cs;
	uint16_t ds;
	uint16_t ss;
	uint16_t es;
	uint16_t fs;
	uint16_t gs;
};

struct ioapic_redirection
{
	uint8_t vector;
	uint8_t delivery_mode;
	uint8_t destination_mode;
	uint8_t delivery_status;
	uint8_t pin_polarity;
	uint8_t remote_irr;
	uint8_t trigger_mode;
	uint8_t mask;
	uint8_t destination;

	uint64_t reserved;
};

/* acpi.c */
void setup_acpi(uint64_t, struct ioapic_info *);

/* apic.c */
void setup_apic(struct ioapic_info *);
void apic_end_of_interrupt(void);
struct ioapic_redirection read_redirection(uint8_t);
void write_redirection(uint8_t, struct ioapic_redirection);

/* boot.c */
uint64_t cpu_count(void);
uint8_t boot_apic_id(void);

/* descriptors */
void setup_descriptors(void);

/* error.c */
void assert(bool);

/* font.c */
void font_init(void);
void font_draw(char8_t *, uint32_t, uint32_t, uint32_t, uint32_t);

/* keyboard.c */
void setup_keyboard(void);
bool keyboard_interrupt_handler(uint32_t);

/* main.c */
void main(struct boot_info *);

/* nasty.S */
struct table_reg;
[[noreturn]] void halt(void);
void disable_interrupts(void);
void enable_interrupts(void);
void set_gdt(struct table_reg *, uint64_t, uint64_t, uint64_t);
void set_idt(struct table_reg *);
uint64_t get_cr2(void);
uint64_t get_cr3(void);
extern void (*isr_stubs[33])(void);
void dump_regs(struct cpu_regs *);
uint64_t get_msr(uint32_t);
uint8_t in_uint8(uint8_t);

/* paging.c */
void setup_paging(struct boot_info *);
bool page_fault_handler(uint32_t);
uint64_t map_page(uint64_t, uint64_t, bool);

/* panic.c */
[[noreturn]] void panic(void);

/* screen.c */
void screen_init(struct framebuffer *);
void screen_draw_pixel(uint32_t, uint32_t, uint32_t);
void print(char8_t *, ...);

/* utf8.c */
int utf8_char_length(const char8_t *);
int utf8_cmp_n(const char8_t *, const char8_t *, uint64_t);
uint32_t utf8_value(const char8_t *);

/* util.c */
uint16_t read_uint16_le(const uint8_t *);
uint16_t read_uint16_be(const uint8_t *);
uint32_t read_uint32_le(const uint8_t *);
void write_uint16_le(uint8_t *, uint16_t);
void write_uint32_le(uint8_t *, uint32_t);
void write_uint64_le(uint8_t *, uint64_t);
int memcmp(const void *, const void *, size_t);
void memset(void *, uint8_t, size_t);
void memcpy(void *, void *, size_t);