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3 Commits

Author SHA1 Message Date
cc9aca2595 fix: gdt add stack 2024-09-10 16:39:31 +02:00
07ff7f6087 lib: add: memcmp 2024-09-10 16:38:21 +02:00
8958b87f65 lib: add: inw, outw 2024-09-10 16:38:21 +02:00
4 changed files with 36 additions and 6 deletions

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@ -8,3 +8,4 @@ int strncmp(const char *s1, const char *s2, size_t n);
size_t strlen(const char *str); size_t strlen(const char *str);
char *strstr(const char *haystack, const char *needle); char *strstr(const char *haystack, const char *needle);
void *memcpy(void *dest, const void *src, size_t n); void *memcpy(void *dest, const void *src, size_t n);
int memcmp(const void *s1, const void *s2, size_t n);

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@ -13,3 +13,15 @@ static inline uint8_t inb(uint16_t port)
__asm__ volatile("inb %w1, %b0" : "=a"(ret) : "Nd"(port) : "memory"); __asm__ volatile("inb %w1, %b0" : "=a"(ret) : "Nd"(port) : "memory");
return ret; return ret;
} }
static inline void outw(uint16_t port, uint16_t val)
{
__asm__ volatile("outb %b0, %w1" : : "a"(val), "Nd"(port) : "memory");
}
static inline uint16_t inw(uint16_t port)
{
uint8_t ret;
__asm__ volatile("inb %w1, %b0" : "=a"(ret) : "Nd"(port) : "memory");
return ret;
}

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@ -0,0 +1,13 @@
#include <stddef.h>
int memcmp(const void *s1, const void *s2, size_t n)
{
const char *str1 = s1;
const char *str2 = s2;
size_t i;
if (n == 0)
return 0;
for (i = 0; str1[i] == str2[i] && i < n - 1; i++);
return str1[i] - str2[i];
}

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@ -50,9 +50,11 @@ void initGdt()
.base = 0, .limit = 0xFFFFF, .access_byte = 0x92, .flags = 0xC}; .base = 0, .limit = 0xFFFFF, .access_byte = 0x92, .flags = 0xC};
encodeGdtEntry(gdt_entries[2], gdt_entry_kernel_mode_data_segment); encodeGdtEntry(gdt_entries[2], gdt_entry_kernel_mode_data_segment);
struct gdt_entry gdt_entry_kernel_mode_stack_segment = { struct gdt_entry gdt_entry_kernel_mode_stack_segment = { .base = 0x0,
.base = 0x0, .limit = 0x0, .access_byte = 0x97, .flags = 0x0D}; .limit = 0x0,
encodeGdtEntry(gdt_entries[3], gdt_entry_kernel_mode_data_segment); .access_byte = 0x97,
.flags = 0x0D };
encodeGdtEntry(gdt_entries[3], gdt_entry_kernel_mode_stack_segment);
struct gdt_entry gdt_entry_user_mode_code_segment = { struct gdt_entry gdt_entry_user_mode_code_segment = {
.base = 0, .limit = 0xFFFFF, .access_byte = 0xFA, .flags = 0xC}; .base = 0, .limit = 0xFFFFF, .access_byte = 0xFA, .flags = 0xC};
@ -62,9 +64,11 @@ void initGdt()
.base = 0, .limit = 0xFFFFF, .access_byte = 0xF2, .flags = 0xC}; .base = 0, .limit = 0xFFFFF, .access_byte = 0xF2, .flags = 0xC};
encodeGdtEntry(gdt_entries[5], gdt_entry_user_mode_data_segment); encodeGdtEntry(gdt_entries[5], gdt_entry_user_mode_data_segment);
struct gdt_entry gdt_entry_user_mode_stack_segment = { struct gdt_entry gdt_entry_user_mode_stack_segment = { .base = 0x0,
.base = 0x0, .limit = 0x0, .access_byte = 0xF7, .flags = 0x0D}; .limit = 0x0,
encodeGdtEntry(gdt_entries[6], gdt_entry_user_mode_data_segment); .access_byte = 0xF7,
.flags = 0x0D };
encodeGdtEntry(gdt_entries[6], gdt_entry_user_mode_stack_segment);
memcpy((void *)gdtr.base, (void *)gdt_entries, (size_t)GDT_SIZE); memcpy((void *)gdtr.base, (void *)gdt_entries, (size_t)GDT_SIZE);