From 95cd78840f0891e60f5ebecc8a8eb4fbaf3c2ebf Mon Sep 17 00:00:00 2001 From: Danny Holman Date: Sun, 12 Jan 2025 01:17:36 -0600 Subject: PROJECT RESTRUCTURING Move the entire kernel into its own directory. Create new directories for system commands, libraries and other required essentials for a complete Unix-like operating system. Signed-off-by: Danny Holman --- arch/i386/kernel/gdt.c | 58 -------------------------------------------------- 1 file changed, 58 deletions(-) delete mode 100644 arch/i386/kernel/gdt.c (limited to 'arch/i386/kernel/gdt.c') diff --git a/arch/i386/kernel/gdt.c b/arch/i386/kernel/gdt.c deleted file mode 100644 index 0d9e1d2..0000000 --- a/arch/i386/kernel/gdt.c +++ /dev/null @@ -1,58 +0,0 @@ -#include -#include -#include - -struct gdt_entry desc[6]; -struct gdt_ptr gp; -struct tss_entry tss_entry; - -void gdt_set_gate(int num, uint32_t base, uint32_t limit, uint8_t access, uint8_t gran) { - desc[num].base_low = (base & 0xFFFF); - desc[num].base_middle = (base >> 16) & 0xFF; - desc[num].base_high = (base >> 24) & 0xFF; - - desc[num].limit_low = (limit & 0xFFFF); - desc[num].gran = (limit >> 16) & 0x0F; - desc[num].gran |= (gran & 0xF0); - desc[num].access = access; -} - -void write_tss(int num, uint32_t ss0, uint32_t esp0) { - uint32_t base = (uint32_t)&tss_entry; - uint32_t limit = base + sizeof(struct tss_entry); - - gdt_set_gate(num, base, limit, 0x89, 0x00); - memset(&tss_entry, 0x0, sizeof(tss_entry)); - - tss_entry.ss0 = ss0; - tss_entry.esp0 = esp0; - tss_entry.cs = 0x0B; - tss_entry.ss = 0x13; - tss_entry.ds = 0x13; - tss_entry.es = 0x13; - tss_entry.fs = 0x13; - tss_entry.gs = 0x13; - tss_entry.iomap_base = sizeof(tss_entry); -} - -void set_kernel_esp(uint32_t esp) { - tss_entry.esp0 = esp; -} - -void gdt_install(void) { - gp.limit = (sizeof(struct gdt_entry) * 6) - 1; - gp.base = (uint32_t)&desc; - - gdt_set_gate(0, 0, 0, 0, 0); - gdt_set_gate(1, 0, 0xFFFFF, 0x9A, 0xCF); - gdt_set_gate(2, 0, 0xFFFFF, 0x92, 0xCF); - gdt_set_gate(3, 0, 0xFFFFF, 0xFA, 0xCF); - gdt_set_gate(4, 0, 0xFFFFF, 0xF2, 0xCF); - - uint32_t esp; - __asm__ volatile("movl %%esp, %0" : "=r"(esp)); - write_tss(5, 0x10, esp); - - flush_gdt(); - flush_tss(); -} -- cgit v1.2.3