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feat: Added nanoprintf, kprintf and GDT

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This commit is contained in:
Kevin Alavik 2025-05-14 13:57:53 +02:00
parent aa5a1e8e1a
commit 248879c099
Signed by: cmpsb
GPG key ID: 10D1CC0526FDC6D7
9 changed files with 1346 additions and 5 deletions
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52
kernel/src/arch/gdt.h Normal file
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#ifndef GDT_H
#define GDT_H
#include <stdint.h>
// GDT Access Flags
#define GDT_ACCESS_PRESENT 0x80 // Segment is present
#define GDT_ACCESS_RING0 0x00 // Privilege Level 0 (Kernel)
#define GDT_ACCESS_RING3 0x60 // Privilege Level 3 (User)
#define GDT_ACCESS_SYSTEM 0x00 // System segment (e.g., TSS)
#define GDT_ACCESS_CODE 0x18 // Code segment (Executable)
#define GDT_ACCESS_DATA 0x10 // Data segment (Readable/Writable)
#define GDT_ACCESS_DIRECTION 0x04 // Direction bit (0 = Grows up, 1 = Grows down)
#define GDT_ACCESS_EXECUTABLE 0x08 // Executable segment
#define GDT_ACCESS_RW 0x02 // Readable for code, Writable for data
#define GDT_ACCESS_ACCESSED 0x01 // CPU sets this when accessed
// Common Access Flags
#define GDT_KERNEL_CODE (GDT_ACCESS_PRESENT | GDT_ACCESS_RING0 | GDT_ACCESS_CODE | GDT_ACCESS_EXECUTABLE | GDT_ACCESS_RW)
#define GDT_KERNEL_DATA (GDT_ACCESS_PRESENT | GDT_ACCESS_RING0 | GDT_ACCESS_DATA | GDT_ACCESS_RW)
#define GDT_USER_CODE (GDT_ACCESS_PRESENT | GDT_ACCESS_RING3 | GDT_ACCESS_CODE | GDT_ACCESS_EXECUTABLE | GDT_ACCESS_RW)
#define GDT_USER_DATA (GDT_ACCESS_PRESENT | GDT_ACCESS_RING3 | GDT_ACCESS_DATA | GDT_ACCESS_RW)
#define GDT_TSS 0xE9
// Granularity Flags
#define GDT_GRANULARITY_4K 0x80
#define GDT_GRANULARITY_32B 0x40
#define GDT_GRANULARITY_LONG_MODE 0x20
#define GDT_GRANULARITY_FLAT (GDT_GRANULARITY_4K | GDT_GRANULARITY_LONG_MODE)
typedef struct gdt_entry
{
uint16_t limit_low;
uint16_t base_low;
uint8_t base_middle;
uint8_t access;
uint8_t granularity;
uint8_t base_high;
} __attribute__((packed)) gdt_entry_t;
typedef struct gdt_ptr
{
uint16_t limit;
uint64_t base;
} __attribute__((packed)) gdt_ptr_t;
extern gdt_ptr_t gdt_ptr;
void gdt_init();
void gdt_flush(gdt_ptr_t gdt_ptr);
#endif // GDT_H