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Making kernel Higher-Half

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This commit is contained in:
Loic Guegan 2021-04-27 19:02:17 +02:00
parent 9dc527b3be
commit f13b26eeb4
18 changed files with 290 additions and 131 deletions
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5
src/Makefile
View file

@ -1,5 +1,5 @@
EXEC := boucane
CC := g++ -nostdlib -nostdinc -no-pie -fno-builtin -fno-stack-protector -I ./ -I include
CC := g++ -mcmodel=large -nostdlib -nostdinc -no-pie -fno-builtin -fno-stack-protector -I ./ -I include
LD_SCRIPT := linker.ld
# Note that BOOT_OBJ do not match boot.S
@ -14,8 +14,7 @@ RES_OBJ := $(addsuffix .o,$(basename $(shell find ./res -type f)))
all: $(EXEC)
$(EXEC): boot/boot.o $(BOOT_OBJ) $(DRIVERS_OBJ) $(LIBS_OBJ) $(CORE_OBJ) $(RES_OBJ) boucane.o
echo "Resource: $(RES_OBJ)"
$(CC) -n -T $(LD_SCRIPT) -nostdlib -o $@ $^
$(CC) -T $(LD_SCRIPT) -nostdlib -o $@ $^
%.o: %.S
as -o $@ $^

53
src/boot/boot.S
View file

@ -2,9 +2,7 @@
.globl MB_INFO
.extern _bss_start
.extern _bss_end
.extern boucane
.set STACK_LOCATION, 0x1FFFFF
.extern higherhalf
.section .multiboot
@ -37,7 +35,7 @@ mb_header_start:
# ----------- End tag
# ----------- Ask framebuffer tag
.align 8
.short 5
.short 6
.short 1
.int 20
.int 0
@ -57,16 +55,6 @@ MB_INFO: # Will contains the Multiboot2 information data structure address
_start:
mov %ebx, (MB_INFO)
# Zeroing the .bss section
mov $_bss_start, %eax
mov $_bss_end, %ebx
start_zeroing:
movb $0x0, (%eax)
cmp %eax, %ebx
je end_zeroing
inc %eax
jmp start_zeroing
end_zeroing:
# ----- Setup PAE Paging (identity on the first 10MB)
mov $8192, %ecx # 8*4096/4 (8 tables of 4096 byte each divide by 4 because of movl)
mov $0, %eax
@ -117,7 +105,7 @@ mov %eax, %cr0
# Now we are in Compatibility mode
# Now we need to set CS.L=1 (setting up a 64 bit GDT)
lgdt (gdtr)
lgdt (boot_gdtr)
ljmp $0x08, $new_cs
new_cs:
@ -132,27 +120,42 @@ mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
mov $STACK_LOCATION, %esp
mov $__stack_pma, %esp
# Run boucane
jmp boucane
# Setup
call trampoline
mov $__kernel_vma, %rsp
# Zeroing the .bss section
mov $__bss_start, %rax
mov $__bss_end, %rbx
start_zeroing:
movb $0x0, (%rax)
cmp %rax, %rbx
je end_zeroing
inc %rax
jmp start_zeroing
end_zeroing:
# Launch kernel
call boucane
# GDT
gdt64:
gdt64_null:
boot_gdt64:
boot_gdt64_null:
.long 0
.long 0
gdt64_cs:
boot_gdt64_cs:
.long 0
.byte 0
.byte 0b10011100
.byte 0b00100000
.byte 0
gdt64_ds:
boot_gdt64_ds:
.long 0
.byte 0
.byte 0b10010010
.word 0
gdtr:
.word . - gdt64 - 1
.quad gdt64
boot_gdtr:
.word . - boot_gdt64 - 1
.quad boot_gdt64

4
src/boot/multiboot2.cc
View file

@ -1,9 +1,13 @@
#include "multiboot2.hpp"
#include "core/paging.hpp"
#include "libs/string.hpp"
#include "libs/stdio.hpp"
u32* mb2_find_tag(u32 *mb2_info_addr, char type){
PAGING_MAP(mb2_info_addr);
u32 size=(u32)mb2_info_addr[0];
for(u64 i=0;i<size/8;i++)
PAGING_MAP(mb2_info_addr+i*4096);
char *location=((char*)mb2_info_addr)+8; // Goto first tag
char *start=(char*)mb2_info_addr;

1
src/boot/multiboot2.hpp
View file

@ -1,6 +1,7 @@
#pragma once
#include "core/types.hpp"
#include "include/boucane.hpp"
typedef struct TAG_HEADER {
u32 type;

94
src/boot/trampoline.cc Normal file
View file

@ -0,0 +1,94 @@
/**
* The usage of data that could goes
* to the .bss section is forbidden here
*/
#include "core/types.hpp"
#include "core/paging.hpp"
/// @brief Define where first PAE paging paging will be
u64 trampoline_next_page;
u64 trampoline_paging_allocate_table(){
for(u64 i=0;i<512;i++)
((u64*)trampoline_next_page)[i]=0;
u64 ret=trampoline_next_page;
trampoline_next_page+=4096;
return ret;
}
void trampoline_paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options){
u64 pml4=virt>>39&0x1FF;
u64 pdp=virt>>30&0x1FF;
u64 pd=virt>>21&0x1FF;
u64 pt=virt>>12&0x1FF;
options&=0xFFF; // Ensure options are on 12bits
// Solve pdp
if(pml4_table[pml4] == 0){
pml4_table[pml4]=(u64)trampoline_paging_allocate_table();
pml4_table[pml4]|=options;
trampoline_paging_allocate_addr(pml4_table,virt,phy,options);
return;
}
// Solve pd
u64* pdp_table=(u64*)PAGE(pml4_table[pml4]);
if(pdp_table[pdp] == 0){
pdp_table[pdp]=(u64)trampoline_paging_allocate_table();
pdp_table[pdp]|=options;
trampoline_paging_allocate_addr(pml4_table,virt,phy,options);
return;
}
// Solve pt
u64* pd_table=(u64*)PAGE(pdp_table[pdp]);
if(pd_table[pd] == 0){
pd_table[pd]=(u64)trampoline_paging_allocate_table();
pd_table[pd]|=options;
trampoline_paging_allocate_addr(pml4_table,virt,phy,options);
return;
}
// Solve address
u64* pt_table=(u64*)PAGE(pd_table[pd]);
if(pt_table[pt] == 0){
pt_table[pt]=PAGE(phy);
pt_table[pt]|=options;
return;
}
}
/**
* Setup High-Half Kernel Paging
*/
extern "C" void trampoline(){
u64 kernel_vma,stack_pma;
asm("movq $__kernel_vma, %0":"=r"(kernel_vma));
asm("movq $__userspace_pma, %0":"=r"(trampoline_next_page));
asm("movq $__stack_pma, %0":"=r"(stack_pma));
// ----- Build the trampoline paging tables
u64 *pml4=(u64*)trampoline_paging_allocate_table();
// Higher Half kernel
for(u64 i=0;i<=0x1000000;i+=4096){
trampoline_paging_allocate_addr(pml4,kernel_vma+i,i,0x3);
}
// Stack
trampoline_paging_allocate_addr(pml4,kernel_vma-4096,stack_pma,0x3);
// First bytes for current eip
for(u64 i=0;i<=0x1000000;i+=4096){
trampoline_paging_allocate_addr(pml4,i,i,0x3);
}
// Test
for(u64 i=0xe0000000;i<=0xef000000;i+=4096){
trampoline_paging_allocate_addr(pml4,i,i,0x3);
}
// Load new pml4
asm volatile(
"movq %0, %%rax \n\t"
"movq %%rax, %%cr3 \n\t"
:: "r" (pml4));
}

39
src/boucane.cc
View file

@ -8,25 +8,19 @@
#include "drivers/framebuffer.hpp"
#include "libs/stdio.hpp"
#include "core/asm.hpp"
extern u32 MB_INFO;
extern u64 res_binary_res_terminus_psf_start;
extern "C" void boucane(){
//clear();
//printk("Booting Boucane v%d.%d.%d\n",VERSION_MAJOR,VERSION_MINOR, VERSION_PATH);
//idt_enable_interrupt();
// Init data structures
LOAD_GDT();
paging_enable();
idt_enable_interrupt();
FRAMEBUFFER fb_info;
if(mb2_find_framebuffer((u32*)MB_INFO, &fb_info)){
if(mb2_find_framebuffer((u32*)&MB_INFO, &fb_info)){
if(fb_info.bpp>16){
FB_CFG conf;
conf.depth=fb_info.bpp;
@ -39,25 +33,10 @@ extern "C" void boucane(){
__putchar=psf_putchar;
}
}
vga_t_init();
vga_t_clear();
printk("Booting Boucane v%d.%d.%d\n",VERSION_MAJOR,VERSION_MINOR, VERSION_PATH);
printk("Jean");
printk("Loic");
//framebuffer_clear();
//apic_enable();
/* u64 p;
u32 size;
if(mb2_find_old_rsdp((u32*)MB_INFO,&p,&size)){
acpi_init((void*)p);
}*/
//FRAMEBUFFER fb;
//if(mb2_find_framebuffer((u32*)MB_INFO, &fb)){
//printk("Framebuffer found!");
//framebuffer_init(fb.addr, fb.pitch, fb.bpp);
//__putchar=psf_print;
//printk("Hello");
//}
while(1);
}

11
src/core/apic.cc
View file

@ -5,18 +5,17 @@
#include "asm.hpp"
#include "libs/stdio.hpp"
extern u64* kpml4;
char enable=0;
#define APIC_LAPIC_ADDR 0xFEE00000
#define APIC_IOAPIC_ADDR 0xFEC00000
#define APIC_LAPIC_REG_SPURIOUS 0xF0
void apic_enable(){
// Allocate APIC registers
paging_allocate_addr(kpml4, APIC_LAPIC_ADDR, APIC_LAPIC_ADDR,
PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
paging_allocate_addr(kpml4, APIC_IOAPIC_ADDR, APIC_IOAPIC_ADDR,
PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
// Allocate APIC registers TODODODODOOD!!!!!
// paging_allocate_addr(kpml4, APIC_LAPIC_ADDR, APIC_LAPIC_ADDR,
//PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
//paging_allocate_addr(kpml4, APIC_IOAPIC_ADDR, APIC_IOAPIC_ADDR,
//PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
// Configure APIC register location
u32 h=APIC_LAPIC_ADDR>>32;

2
src/core/apic.hpp
View file

@ -1,6 +1,6 @@
#pragma once
#include "include/boucane.hpp"
void apic_enable();

25
src/core/gdt.S Normal file
View file

@ -0,0 +1,25 @@
.code64
gdt64:
gdt64_null:
.long 0
.long 0
gdt64_cs:
.long 0
.byte 0
.byte 0b10011100
.byte 0b00100000
.byte 0
gdt64_ds:
.long 0
.byte 0
.byte 0b10010010
.word 0
gdtr:
.word . - gdt64 - 1
.quad gdt64
.global load_gdt
load_gdt:
lgdt (gdtr)
ret

28
src/core/idt.cc
View file

@ -1,14 +1,16 @@
#include "idt.hpp"
#include "core/paging.hpp"
#include "libs/string.hpp"
IDT_REGISTER IDTR = {
IDT_GATE_SIZE*IDT_MAX_ENTRIES,
IDT_ADDR
};
u32 idt[IDT_MAX_ENTRIES][4] __attribute__((aligned(4096)));;
IDT_REGISTER IDTR;
extern u64 INT_DEFAULT,INT_0,INT_14,INT_KBD;
void idt_enable_interrupt(void){
IDTR.base=((u64)idt);
IDTR.limit=sizeof(idt);
IDT_DESCRIPTOR d;
d.ign=0;
d.ist=0;
@ -25,7 +27,7 @@ void idt_enable_interrupt(void){
d.offset=(u64)&INT_14;
idt_write_descriptor(d, i);
}
else if(i==60){ // Page fault
else if(i==60){ // Keyboard
d.offset=(u64)&INT_KBD;
idt_write_descriptor(d, i);
}
@ -34,12 +36,11 @@ void idt_enable_interrupt(void){
idt_write_descriptor(d, i);
}
}
// Enable interrupts
asm(
"lidt (IDTR) \n\t"
"sti \n\t"
);
"lidt (IDTR) \n\t"
"sti \n\t ");
}
void idt_write_descriptor(IDT_DESCRIPTOR desc, u16 index){
@ -47,9 +48,8 @@ void idt_write_descriptor(IDT_DESCRIPTOR desc, u16 index){
u32 desc32_63=desc.ist | desc.options | (desc.offset&0xFFFF0000);
u32 desc64_95=desc.offset>>32;
u32 desc96_127=desc.ign;
u32* dst=(u32*)(IDTR.base+index*IDT_GATE_SIZE);
*dst=desc0_31;
*(dst+1)=desc32_63;
*(dst+2)=desc64_95;
*(dst+3)=desc96_127;
idt[index][0]=desc0_31;
idt[index][1]=desc32_63;
idt[index][2]=desc64_95;
idt[index][3]=desc96_127;
}

5
src/core/idt.hpp
View file

@ -5,7 +5,7 @@
#define IDT_GATE_SIZE 16
#define IDT_MAX_ENTRIES 200
#define IDT_ADDR 0x200000
#define IDT_ADDR 0
#define IDT_OPT_P (1 << 15)
#define IDT_OPT_TYPE_INT 0xE << 8
@ -27,5 +27,8 @@ typedef struct IDT_DESCRIPTOR {
u32 ign;
} __attribute__((packed)) IDT_DESCRIPTOR;
/// @brief 3 u32 per entry
extern u32 idt[IDT_MAX_ENTRIES][4];
void idt_enable_interrupt(void);
void idt_write_descriptor(IDT_DESCRIPTOR desc, u16 index);

4
src/core/int.S
View file

@ -1,3 +1,5 @@
.code64
.extern printk
.extern ack
@ -40,4 +42,4 @@ MSG_INT_14:
MSG_INT_KBD:
.asciz "Key press!"
MSG:
.asciz "Called :)\n"
.asciz "Called :)\n"

62
src/core/paging.cc
View file

@ -4,29 +4,50 @@
#include "libs/string.hpp"
char paging_status[PAGING_MAX_PAGE / 8];
u64* kpml4;
u64 kernel_vma,stack_pma,userspace_pma;
u64 kpages[MAX_TABLES][512] __attribute__((aligned(4096)));
int kpages_next=1; // First page is for the pml4
u64* paging_allocate_table(){
u64 addr=(u64)kpages[kpages_next];
u64* allocated=(u64*)(addr-kernel_vma);
kpages_next++;
return allocated;
}
void paging_enable() {
// Init linker variables
asm("movq $__kernel_vma, %0":"=r"(kernel_vma));
asm("movq $__userspace_pma, %0":"=r"(userspace_pma));
asm("movq $__stack_pma, %0":"=r"(stack_pma));
// Init status
for (int i = 0; i < PAGING_MAX_PAGE / 8; i++) {
paging_status[i] = 0;
}
// Init tables
for(int i=0;i<MAX_TABLES;i++){
memset(kpages[i], 0, 512*64);
}
// Allocate paging for the kernel (to not override the source
// code during the next paging_allocate_table() calls)
paging_allocate_contiguous(PAGING_KERNEL_USED_PAGE);
paging_allocate_contiguous(userspace_pma/4096);
// Setting up new kernel address space
kpml4=paging_allocate_table();
for(int i=0;i<PAGING_KERNEL_SPACE_MAX_PAGE;i++){
int addr=i*4096;
paging_allocate_addr(kpml4,addr,addr, PAGING_OPT_P|PAGING_OPT_RW); // Identity map
for(u64 i=0;i<=0x10000000;i+=4096){
paging_allocate_addr(kpages[0],kernel_vma+i,i, 0x3,0); // Identity map
}
// 4096 bytes stack
paging_allocate_addr(kpages[0],kernel_vma-4096,stack_pma,0x3,0);
// Load new pml4
u64 kpage_phy=((u64)kpages[0]-kernel_vma);
asm volatile(
"movq %0, %%rax \n\t"
"movq %%rax, %%cr3 \n\t"
:: "r" (kpml4));
"mov %0, %%rax \n\t"
"mov %%rax, %%cr3 \n\t"
:: "r" (kpage_phy));
}
u64 paging_as_phy(u64* pml4_table, u64 virt){
@ -40,6 +61,7 @@ u64 paging_as_phy(u64* pml4_table, u64 virt){
u64* pt_table=(u64*)PAGE(pd_table[pd]);
return((PAGE(pt_table[pt]))|(virt&0xFFF));
}
u64* paging_allocate_contiguous(int npages){
int n_contiguous=0;
for (int i = 0; i < PAGING_MAX_PAGE / 8; i++) {
@ -116,12 +138,6 @@ void paging_dump(int min, int max) {
}
}
u64* paging_allocate_table(){
u64* table=paging_allocate_contiguous(8);
memset(table, 0, 32768); // nb_entries * entry size = 512 * 64
return table;
}
void paging_deallocate_table(u64* table){
char *c_table=(char*)PAGE((u64)table);
for(u8 i=0;i<8;i++){
@ -130,7 +146,7 @@ void paging_deallocate_table(u64* table){
}
}
void paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options){
void paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options, u64 offset){
u16 pml4=virt>>39&0x1FF;
u16 pdp=virt>>30&0x1FF;
u16 pd=virt>>21&0x1FF;
@ -141,27 +157,29 @@ void paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options){
if(pml4_table[pml4] == 0){
pml4_table[pml4]=(u64)paging_allocate_table();
pml4_table[pml4]|=options;
paging_allocate_addr(pml4_table,virt,phy,options);
paging_allocate_addr(pml4_table,virt,phy,options,offset);
return;
}
// Solve pd
u64* pdp_table=(u64*)PAGE(pml4_table[pml4]);
u64* pdp_table=(u64*)(PAGE(pml4_table[pml4])+offset);
if(pdp_table[pdp] == 0){
pdp_table[pdp]=(u64)paging_allocate_table();
pdp_table[pdp]|=options;
paging_allocate_addr(pml4_table,virt,phy,options);
paging_allocate_addr(pml4_table,virt,phy,options,offset);
return;
}
// Solve pt
u64* pd_table=(u64*)PAGE(pdp_table[pdp]);
u64* pd_table=(u64*)(PAGE(pdp_table[pdp])+offset);
if(pd_table[pd] == 0){
pd_table[pd]=(u64)paging_allocate_table();
pd_table[pd]|=options;
paging_allocate_addr(pml4_table,virt,phy,options);
paging_allocate_addr(pml4_table,virt,phy,options,offset);
return;
}
// Solve address
u64* pt_table=(u64*)PAGE(pd_table[pd]);
u64* pt_table=(u64*)(PAGE(pd_table[pd])+offset);
if(pt_table[pt] == 0){
pt_table[pt]=PAGE(phy);
pt_table[pt]|=options;

16
src/core/paging.hpp
View file

@ -18,9 +18,14 @@
/// @brief Get page address that contain addr
#define PAGE(addr) (addr&(~(0xFFF)))
#define PAGING_MAP(addr) paging_allocate_addr(kpml4,(u64)(addr),(u64)(addr),PAGING_OPT_P|PAGING_OPT_RW)
#define PAGING_MAP(addr) paging_allocate_addr(kpages[0],(u64)(addr),(u64)(addr),PAGING_OPT_P|PAGING_OPT_RW,kernel_vma)
#define MAX_TABLES 280
extern u64* kpml4;
/// @brief All PAE table structures are allocated here
extern u64 kpages[MAX_TABLES][512];
/// @brief Various variables from the linker
extern u64 kernel_vma,stack_pma,userspace_pma;
/**
* Setup and enable PAE paging
@ -56,13 +61,16 @@ void paging_deallocate_table(u64* table);
/**
* Allocate table structure (pml4, pdp etc..)
*/
u64* paging_allocate_table();
u64* paging_allocate_table_local();
/**
* Map virtual page associated to virt
* to the physical page associated with phy
* Offset can be used to convert pml4_table address
* content to virtual addresses (since physical addresses from the pml4_table are not
* available after the trampoline into High-Half memory)
*/
void paging_allocate_addr(u64* pml4_table,u64 virt, u64 phy, u16 options);
void paging_allocate_addr(u64* pml4_table,u64 virt, u64 phy, u16 options, u64 offset);
/**
* Get associated physical address

9
src/drivers/vga_t.cc
View file

@ -1,5 +1,7 @@
#include "vga_t.hpp"
#include "include/boucane.hpp"
#define MAX_COL 80
#define MAX_LINE 25
@ -11,6 +13,11 @@ VIDEO_STATE VS={
GRAY,
};
void vga_t_init(){
PAGING_MAP(0xB8000);
PAGING_MAP(0xB8000+4096);
}
void vga_t_putchar(char c){
// Handle newline here
if(c=='\n'){
@ -39,7 +46,7 @@ void vga_t_putchar(char c){
}
}
void clear(){
void vga_t_clear(){
for(u8 i=0;i<MAX_LINE;i++){
vga_t_scrollup();
}

2
src/drivers/vga_t.hpp
View file

@ -16,6 +16,8 @@ typedef struct VIDEO_STATE {
u8 fg;
} VIDEO_STATE;
void vga_t_init();
/**
* Print char
*/

2
src/include/boucane.hpp
View file

@ -10,4 +10,4 @@
#include "libs/stdio.hpp"
#include "libs/string.hpp"
extern u64* kpml4;
#define LOAD_GDT() asm("call load_gdt")

59
src/linker.ld
View file

@ -1,30 +1,45 @@
ENTRY(_start)
OUTPUT_FORMAT(elf64-x86-64)
ENTRY(_start)
__kernel_vma = 0xFFFFFFFF80000000;
__boot_pma = 1M;
__stack_pma = 0x3FFFFF;
__stack_size = 4096;
__userspace_pma = 0x400000;
PHDRS
{
boot PT_LOAD;
kernel PT_LOAD;
}
SECTIONS {
. = 1M;
.text : ALIGN(4)
. = __boot_pma;
.boot ALIGN(4096) :
{
*boot.o(.multiboot)
*boot.o(.text)
*(.text)
}
.rodata : ALIGN(4)
{
*(.rodata)
}
.data : ALIGN(4)
{
*(.data)
}
.bss : ALIGN(4)
{
_bss_start = .;
*(.bss);
_bss_end = .;
*(COMMON);
}
*trampoline.o(.text .text.* .data .data.* .rodata .rodata.* .bss)
} :boot
. += __kernel_vma;
.text ALIGN(4096) : AT(ADDR(.text)-__kernel_vma)
{
*boot.o(.multiboot)
*boot.o(.text)
*(.text .text.*)
*(.rodata .rodata.*)
*(.data .data.*)
}:kernel
.bss ALIGN(4096) : AT(ADDR(.bss)-__kernel_vma)
{
__bss_start = .;
*(.bss);
__bss_end = .;
*(COMMON);
ASSERT( (. - ABSOLUTE(__kernel_vma)) < (ABSOLUTE(__stack_pma)-ABSOLUTE(__stack_size)), "No room for stack !!");
}:kernel
/DISCARD/ : { *(.eh_frame) *(.comment) *(.note*) }
}