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fix userspace?

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This commit is contained in:
assada 2025-01-31 16:38:38 +01:00
parent ad929efeb2
commit 79a4f79a24
7 changed files with 149 additions and 62 deletions
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17
boot.s
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@ -1,7 +1,7 @@
.set ALIGN, 1<<0 .set ALIGN, 1<<0
.set MEMINFO, 1<<1 .set MEMINFO, 1<<1
.set FLAGS, ALIGN | MEMINFO .set FLAGS, ALIGN | MEMINFO
.set MAGIC, 0x1BADB002 /* multiboot 1 */ .set MAGIC, 0x1BADB002
.set CHECKSUM, -(MAGIC + FLAGS) .set CHECKSUM, -(MAGIC + FLAGS)
.section .multiboot .section .multiboot
@ -10,7 +10,9 @@
.long FLAGS .long FLAGS
.long CHECKSUM .long CHECKSUM
.section .stack, "aw", @nobits .section .bss
.align 16
.global stack_bottom
.global stack_top .global stack_top
stack_bottom: stack_bottom:
.skip 16384 .skip 16384
@ -22,8 +24,15 @@ stack_top:
_start: _start:
movl $stack_top, %esp movl $stack_top, %esp
push %ebx pushl $0
popf
pushl %ebx
call kernel_main call kernel_main
1:
cli
1: hlt
jmp 1b jmp 1b
.size _start, . - _start

36
gdt.c
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@ -25,39 +25,45 @@ static void gdt_set_gate(uint8_t num, uint32_t base, uint32_t limit, uint8_t acc
gdt[num].access = access; gdt[num].access = access;
} }
static void tss_install(uint8_t num, uint16_t kernel_ss, uint16_t kernel_esp) void tss_install(uint8_t num, uint16_t kernel_ss, uint16_t kernel_esp)
{ {
uint32_t base = (uint32_t)&tss; uint32_t base = (uint32_t)&tss;
uint32_t limit = base + sizeof(Tss_entry); uint32_t limit = sizeof(Tss_entry);
gdt_set_gate(num, base, limit, 0xE9, 0x0);
memset(&tss, 0, sizeof(Tss_entry)); memset(&tss, 0, sizeof(Tss_entry));
tss.ss0 = kernel_ss; tss.ss0 = kernel_ss;
tss.esp0 = kernel_esp + 0x1000; // SHIT tss.esp0 = kernel_esp;
tss.cs = 0x1B; tss.cs = 0x1b;
tss.ss = 0x23; tss.ss = 0x23;
tss.es = 0x23;
tss.ds = 0x23; tss.ds = 0x23;
tss.es = 0x23;
tss.fs = 0x23; tss.fs = 0x23;
tss.gs = 0x23; tss.gs = 0x23;
tss.iopb_off = sizeof(Tss_entry);
gdt_set_gate(num, base, limit, I86_GDT_DESC_ACCESS | I86_GDT_DESC_EXEC_CODE | I86_GDT_DESC_DPL | I86_GDT_DESC_MEMORY, 0x00);
} }
void gdt_install() void gdt_install()
{ {
gdt_set_gate(0, 0x0, 0x0, 0x0, 0x0); // Null segment
gdt_set_gate(1, 0x0, 0xFFFFFFFF, 0x9A, 0xCF); // 0x08 Kernel code segment
gdt_set_gate(2, 0x0, 0xFFFFFFFF, 0x92, 0xCF); // 0x10 Kernel Data segment
gdt_set_gate(3, 0x0, 0xFFFFFFFF, 0xFA, 0xCF); // 0x18 User code segment
gdt_set_gate(4, 0x0, 0xFFFFFFFF, 0xF2, 0xCF); // 0x20 User data segment
tss_install(5, 0x10, stack_top);
gdtp.limit = (sizeof(Gdt_entry) * GDT_ENTRY) - 1; gdtp.limit = (sizeof(Gdt_entry) * GDT_ENTRY) - 1;
gdtp.base = (uint32_t)&gdt; gdtp.base = (uint32_t)&gdt;
gdt_set_gate(0, 0, 0, 0, 0);
gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
tss_install(5, 0x10, (uint32_t)&stack_top);
gdt_flush((uint32_t)&gdtp); gdt_flush((uint32_t)&gdtp);
tss_flush(); tss_flush();
} }

38
gdt.h
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@ -3,7 +3,42 @@
#include <stdint.h> #include <stdint.h>
extern uint32_t stack_top; extern void* stack_top;
//! set access bit
#define I86_GDT_DESC_ACCESS 0x0001 //00000001
//! descriptor is readable and writable. default: read only
#define I86_GDT_DESC_READWRITE 0x0002 //00000010
//! set expansion direction bit
#define I86_GDT_DESC_EXPANSION 0x0004 //00000100
//! executable code segment. Default: data segment
#define I86_GDT_DESC_EXEC_CODE 0x0008 //00001000
//! set code or data descriptor. defult: system defined descriptor
#define I86_GDT_DESC_CODEDATA 0x0010 //00010000
//! set dpl bits
#define I86_GDT_DESC_DPL 0x0060 //01100000
//! set "in memory" bit
#define I86_GDT_DESC_MEMORY 0x0080 //10000000
/** gdt descriptor grandularity bit flags ***/
//! masks out limitHi (High 4 bits of limit)
#define I86_GDT_GRAND_LIMITHI_MASK 0x0f //00001111
//! set os defined bit
#define I86_GDT_GRAND_OS 0x10 //00010000
//! set if 32bit. default: 16 bit
#define I86_GDT_GRAND_32BIT 0x40 //01000000
//! 4k grandularity. default: none
#define I86_GDT_GRAND_4K 0x80 //10000000
typedef struct gdt_entry_t Gdt_entry; typedef struct gdt_entry_t Gdt_entry;
struct gdt_entry_t struct gdt_entry_t
@ -58,6 +93,7 @@ struct tss_entry_t
uint32_t ldt; uint32_t ldt;
uint16_t trap; uint16_t trap;
uint16_t iomap; uint16_t iomap;
uint16_t iopb_off;
} __attribute__((packed)); } __attribute__((packed));
#endif #endif

32
irq.c
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@ -62,22 +62,22 @@ void irq_install(void)
{ {
irq_remap(); irq_remap();
idt_set_gate(32, (uint32_t)irq0, 0x08, 0x8E); idt_set_gate(32, (uint32_t)irq0, 0x08, 0xEE);
idt_set_gate(33, (uint32_t)irq1, 0x08, 0x8E); idt_set_gate(33, (uint32_t)irq1, 0x08, 0xEE);
idt_set_gate(34, (uint32_t)irq2, 0x08, 0x8E); idt_set_gate(34, (uint32_t)irq2, 0x08, 0xEE);
idt_set_gate(35, (uint32_t)irq3, 0x08, 0x8E); idt_set_gate(35, (uint32_t)irq3, 0x08, 0xEE);
idt_set_gate(36, (uint32_t)irq4, 0x08, 0x8E); idt_set_gate(36, (uint32_t)irq4, 0x08, 0xEE);
idt_set_gate(37, (uint32_t)irq5, 0x08, 0x8E); idt_set_gate(37, (uint32_t)irq5, 0x08, 0xEE);
idt_set_gate(38, (uint32_t)irq6, 0x08, 0x8E); idt_set_gate(38, (uint32_t)irq6, 0x08, 0xEE);
idt_set_gate(39, (uint32_t)irq7, 0x08, 0x8E); idt_set_gate(39, (uint32_t)irq7, 0x08, 0xEE);
idt_set_gate(40, (uint32_t)irq8, 0x08, 0x8E); idt_set_gate(40, (uint32_t)irq8, 0x08, 0xEE);
idt_set_gate(41, (uint32_t)irq9, 0x08, 0x8E); idt_set_gate(41, (uint32_t)irq9, 0x08, 0xEE);
idt_set_gate(42, (uint32_t)irq10, 0x08, 0x8E); idt_set_gate(42, (uint32_t)irq10, 0x08, 0xEE);
idt_set_gate(43, (uint32_t)irq11, 0x08, 0x8E); idt_set_gate(43, (uint32_t)irq11, 0x08, 0xEE);
idt_set_gate(44, (uint32_t)irq12, 0x08, 0x8E); idt_set_gate(44, (uint32_t)irq12, 0x08, 0xEE);
idt_set_gate(45, (uint32_t)irq13, 0x08, 0x8E); idt_set_gate(45, (uint32_t)irq13, 0x08, 0xEE);
idt_set_gate(46, (uint32_t)irq14, 0x08, 0x8E); idt_set_gate(46, (uint32_t)irq14, 0x08, 0xEE);
idt_set_gate(47, (uint32_t)irq15, 0x08, 0x8E); idt_set_gate(47, (uint32_t)irq15, 0x08, 0xEE);
sys_enable_interrupts(); sys_enable_interrupts();
} }

8
isr.c
View File

@ -149,7 +149,13 @@ void fault_handler(Stack *registers)
terminal_printf("Exception. System Halted!\n"); terminal_printf("Exception. System Halted!\n");
terminal_printf("Exception: "); terminal_printf("Exception: ");
terminal_printf(exception_messages[registers->id]); terminal_printf(exception_messages[registers->id]);
terminal_printf("\n");
terminal_printf("Error code: %d\n", registers->err_code);
terminal_printf("EIP: %x\n", registers->eip);
terminal_printf("CS: %x\n", registers->cs);
terminal_printf("EFLAGS: %x\n", registers->eflags);
terminal_printf("ESP: %x\n", registers->esp);
terminal_printf("SS: %x\n", registers->ss);
isr_call_handler(registers); isr_call_handler(registers);
for (;;) for (;;)

37
kernel.c
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@ -16,6 +16,7 @@
void kernel_main(void) void kernel_main(void)
{ {
terminal_printf("Kernel start\n");
terminal_initialize(); terminal_initialize();
gdt_install(); gdt_install();
@ -28,22 +29,42 @@ void kernel_main(void)
rtc_init(); rtc_init();
terminal_printf("Kernel initialized\n");
syscall_init(); syscall_init();
terminal_printf("Syscall initialized\n");
sys_enable_interrupts();
terminal_printf("Interrupts enabled\n");
enter_user_space(); enter_user_space();
} }
enum SYSCALLS {
SYS_GETCHAR = 0,
SYS_GET_TIME,
SYS_HALT,
SYS_PRINTF,
SYS_DELAY,
SYS_CLEAR,
SYS_SHELL_INIT
};
void main(void) void main(void)
{ { //TODO: Rework user space calls
int ret;
for (int i = 1; i < 4; i++) for (int i = 1; i < 4; i++)
{ {
terminal_printf("&cTest &7%d\n", i); asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_PRINTF), "b"("&cTest &7%d\n"), "c"(i));
delay(200);
asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_DELAY), "b"(1000));
} }
terminal_clear();
terminal_printf("Welcome to &cDeadOS&7.\n"); asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_CLEAR));
terminal_printf("You are now in user space.\n");
terminal_printf("Type 'help' for a list of available commands.\n");
shell_init(); asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_PRINTF), "b"("Welcome to &cDeadOS&7.\n"));
asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_PRINTF), "b"("You are now in user space.\n"));
asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_PRINTF), "b"("Type 'help' for a list of available commands.\n"));
asm volatile("int $0x80" : "=a"(ret) : "a"(SYS_SHELL_INIT));
} }

31
syscall.c
View File

@ -7,26 +7,31 @@
#include "tty.h" #include "tty.h"
#include "timer.h" #include "timer.h"
#include "rtc.h" #include "rtc.h"
#include "shell.h"
#define NB_SYSCALL 3 #define NB_SYSCALL 7
void *syscalls[NB_SYSCALL] = { void *syscalls[NB_SYSCALL] = {
keyboard_getchar, keyboard_getchar,
get_rtc_time, get_rtc_time,
sys_halt,
sys_halt}; terminal_printf,
delay,
terminal_clear,
shell_init
};
void syscall_handler(Stack *registers) void syscall_handler(Stack *registers)
{ {
int sys_index = registers->eax; if ((registers->cs & 0x3) != 0x3) return;
if (sys_index >= NB_SYSCALL) int sys_index = registers->eax;
return; if (sys_index >= NB_SYSCALL) return;
void *function = syscalls[sys_index]; void *function = syscalls[sys_index];
int ret; int ret;
asm volatile(" push %1; \ asm volatile("sti");
asm volatile (" push %1; \
push %2; \ push %2; \
push %3; \ push %3; \
push %4; \ push %4; \
@ -37,9 +42,13 @@ void syscall_handler(Stack *registers)
pop %%ebx; \ pop %%ebx; \
pop %%ebx; \ pop %%ebx; \
pop %%ebx; \ pop %%ebx; \
" : "=a"(ret) : "r"(registers->edi), "r"(registers->esi), " : "=a" (ret) :
"r"(registers->edx), "r"(registers->ecx), "r" (registers->edi), "r" (registers->esi),
"r"(registers->ebx), "r"(function)); "r" (registers->edx), "r" (registers->ecx),
"r" (registers->ebx), "r" (function));
asm volatile("cli");
registers->eax = ret; registers->eax = ret;
} }