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Espresso 0.0.1c

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This commit is contained in:
David Goeke
2025-07-01 20:39:38 -05:00
parent f9f3faca4f
commit 8648637b51
23 changed files with 384 additions and 419 deletions
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32
drivers/gdt.c
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@ -16,11 +16,21 @@ extern void gdt_flush(uint32_t);
void gdt_install(bool prnt_gdt)
{
create_descriptor(0, 0, 0, 0, prnt_gdt); // Null
create_descriptor(1, 0, 0x000FFFFF, GDT_CODE_PL0, prnt_gdt); // Kernel code
create_descriptor(2, 0, 0x000FFFFF, GDT_DATA_PL0, prnt_gdt); // Kernel data
create_descriptor(3, 0, 0x000FFFFF, GDT_CODE_PL3, prnt_gdt); // User code
create_descriptor(4, 0, 0x000FFFFF, GDT_DATA_PL3, prnt_gdt); // User data
if (prnt_gdt)
{
printf("<===== GDT =====>\n");
}
create_descriptor(0, 0, 0, 0, prnt_gdt); /* Null */
create_descriptor(1, 0, 0x000FFFFF, GDT_CODE_PL0, prnt_gdt); /* Kernel code */
create_descriptor(2, 0, 0x000FFFFF, GDT_DATA_PL0, prnt_gdt); /* Kernel data */
create_descriptor(3, 0, 0x000FFFFF, GDT_CODE_PL3, prnt_gdt); /* User code */
create_descriptor(4, 0, 0x000FFFFF, GDT_DATA_PL3, prnt_gdt); /* User data */
if (prnt_gdt)
{
printf("<===== GDT =====>\n");
}
gp.limit = sizeof(gdt) - 1;
gp.base = (uint32_t)&gdt;
@ -32,15 +42,15 @@ void create_descriptor(int index, uint32_t base, uint32_t limit, uint16_t flag,
{
uint64_t descriptor;
descriptor = limit & 0x000F0000; // limit bits 19:16
descriptor |= (flag << 8) & 0x00F0FF00; // flags and access
descriptor |= (base >> 16) & 0x000000FF; // base bits 23:16
descriptor |= base & 0xFF000000; // base bits 31:24
descriptor = limit & 0x000F0000; /* limit bits 19:16 */
descriptor |= (flag << 8) & 0x00F0FF00; /* flags and access */
descriptor |= (base >> 16) & 0x000000FF; /* base bits 23:16 */
descriptor |= base & 0xFF000000; /* base bits 31:24 */
descriptor <<= 32;
descriptor |= ((uint64_t)base << 16); // base bits 15:0
descriptor |= (limit & 0x0000FFFF); // limit bits 15:0
descriptor |= ((uint64_t)base << 16); /* base bits 15:0 */
descriptor |= (limit & 0x0000FFFF); /* limit bits 15:0 */
gdt[index] = descriptor;