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Improved kernel memory usage

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Moved base linear address to 0xFF800000
Kernel only reserves the page frames it actually needs
Memory for multiboot2 headers is freed
Video memory and APIC registers are dynamically mapped into linear addresses
This commit is contained in:
ngiddings
2021-04-17 03:45:45 -05:00
parent b141582f40
commit 961139df9e
10 changed files with 91 additions and 57 deletions
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43
src/x86/quark_x86.c
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@@ -1,5 +1,7 @@
#include "kernel.h"
#include "pageallocator.h"
#include "allocator.h"
#include "mmgr.h"
#include "multiboot2.h"
#include "memorymap.h"
#include "apic.h"
@@ -11,38 +13,18 @@
#include <stdint.h>
#include <stddef.h>
extern int _kernel_pstart;
extern int _kernel_pend;
extern int _kernel_start;
extern int _kernel_end;
struct kernel_t kernel_state;
int start_paging(uint32_t *directory, uint32_t *table, uint32_t *identityTable)
{
for (int i = 0; i < 1024; i++)
{
uint32_t pte = i * 4096 + 3;
table[i] = pte;
identityTable[i] = pte;
}
directory[0] = ((uint32_t)identityTable) + 3;
directory[1022] = ((uint32_t)table) + 3;
directory[1023] = ((uint32_t)directory) + 3;
asm("mov %0, %%cr3"
:
: "r"(directory));
asm("mov %%cr0, %%eax \n"
"or $0x80010000, %%eax \n"
"mov %%eax, %%cr0"
:
:
: "eax");
return 0;
}
int initialize(void *multiboot_info)
{
initialize_gdt();
initialize_idt();
printf("***%s***\n", PACKAGE_STRING);
initialize_allocator(&_kernel_end, (void*)0xFFC00000);
static struct page_stack_t page_stack;
struct memory_region_t map_array[16];
char bootloader_name[64];
@@ -55,12 +37,19 @@ int initialize(void *multiboot_info)
.array = map_array,
.size = 0,
.capacity = 16}};
void *multiboot_end = multiboot_info + *(uint32_t*)multiboot_info;
multiboot_info += 8;
while (multiboot_info != NULL)
{
multiboot_info = read_multiboot_table(&boot_info, multiboot_info);
}
insert_region(&boot_info.map, 0, 1 << 22, M_UNAVAILABLE);
insert_region(&boot_info.map, (physaddr_t)&_kernel_pstart, (physaddr_t)&_kernel_pend, M_UNAVAILABLE);
for(void *p = (void*)&_kernel_end; p < multiboot_end; p += page_size)
{
unmap_page(p);
}
initialize_screen();
printf("***%s***\n", PACKAGE_STRING);
printf("Type\t\tLocation\t\tSize\n");
for (size_t i = 0; i < boot_info.map.size && boot_info.map.array[i].size > 0; i++)
{
@@ -68,8 +57,8 @@ int initialize(void *multiboot_info)
}
page_stack.base_pointer = (physaddr_t*)0xFFC00000;
page_stack.stack_pointer = (physaddr_t*)0xFFC00000;
page_stack.limit_pointer = (physaddr_t*)0xFF900000;
initialize_page_stack(&page_stack, &boot_info.map, 4096);
page_stack.limit_pointer = (physaddr_t*)0xFFC00000;
initialize_page_stack(&page_stack, &boot_info.map);
apic_enable(page_stack);
apic_registers->divide_config.value = APIC_DIVIDE_128;
apic_registers->lvt_timer.vector = ISR_APIC_TIMER;