memory #7

Merged
xamidev merged 7 commits from memory into main 2026-01-04 09:28:00 +01:00
10 changed files with 113 additions and 7 deletions
Showing only changes of commit 8f5e2eae3e - Show all commits

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@@ -1,4 +1,4 @@
SOURCES = src/io/kbd/ps2.c src/io/serial/serial.c src/io/term/printf.c src/io/term/term.c src/idt/idt.c src/mem/gdt/gdt.c src/mem/misc/utils.c src/time/timer.c src/kmain.c
SOURCES = src/string/string.c src/io/kbd/ps2.c src/io/serial/serial.c src/io/term/printf.c src/io/term/term.c src/idt/idt.c src/mem/gdt/gdt.c src/mem/misc/utils.c src/time/timer.c src/kmain.c
build:
rm -f *.o

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@@ -1,4 +1,9 @@
// Terminal output
/*
There are a couple of bugs here and there but for now I don't care too much
because this shitty implementation will be replaced one day by Flanterm
(once memory management is okay: paging & kernel malloc)
*/
#include <limine.h>
#include <stddef.h>

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@@ -13,9 +13,7 @@ enum ErrorCodes
#include "io/serial/serial.h"
#include "io/term/printf.h"
// Still lacks print formatting...
#define DEBUG(log, ...) \
printf("debug: [%s]: " log "\n", __FILE__, ##__VA_ARGS__); \
fctprintf((void*)&skputc, 0, "debug: [%s]: %s\n", __FILE__, log)
#define DEBUG(log, ...) fctprintf((void*)&skputc, 0, "debug: [%s]: " log "\n", __FILE__, ##__VA_ARGS__)
// printf("debug: [%s]: " log "\n", __FILE__, ##__VA_ARGS__);
#endif

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@@ -22,6 +22,13 @@ static volatile struct limine_framebuffer_request framebuffer_request = {
.revision = 0
};
// Memory map request
__attribute__((used, section(".limine_requests")))
static volatile struct limine_memmap_request memmap_request = {
.id = LIMINE_MEMMAP_REQUEST,
.revision = 0
};
__attribute__((used, section(".limine_requests_start")))
static volatile LIMINE_REQUESTS_START_MARKER;
@@ -51,17 +58,20 @@ void kmain()
term_init();
serial_init();
if (memmap_request.response == NULL) hcf();
memmap_display(memmap_request.response);
CLEAR_INTERRUPTS;
gdt_init();
idt_init();
timer_init();
SET_INTERRUPTS;
keyboard_init(FR);
//keyboard_init(FR);
// Draw something
printf("%s, %s!\n", "Hello", "world");
// Yoohoooooo!
DEBUG("kernel initialized successfully! hanging... wow=%d", 42);
//DEBUG("kernel initialized successfully! hanging... wow=%d", 42);
hcf();
}

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@@ -1,5 +1,8 @@
#include <stddef.h>
#include <stdint.h>
#include <limine.h>
#include "../../kernel.h"
#include "../../string/string.h"
// We won't be linked to standard library, but still need the basic mem* functions
// so everything goes allright with the compiler
@@ -67,4 +70,47 @@ int memcmp(const void* s1, const void* s2, size_t n)
}
return 0;
}
// Display the memmap so we see how the memory is laid out at handoff
void memmap_display(struct limine_memmap_response* response)
{
DEBUG("Got memory map from Limine: revision %u, %u entries", response->revision, response->entry_count);
for (size_t i=0; i<response->entry_count; i++)
{
struct limine_memmap_entry* entry = response->entries[i];
char type[32] = {0};
switch(entry->type)
{
case LIMINE_MEMMAP_USABLE:
strcpy(type, "USABLE");
break;
case LIMINE_MEMMAP_RESERVED:
strcpy(type, "RESERVED");
break;
case LIMINE_MEMMAP_ACPI_RECLAIMABLE:
strcpy(type, "ACPI_RECLAIMABLE");
break;
case LIMINE_MEMMAP_ACPI_NVS:
strcpy(type, "ACPI_NVS");
break;
case LIMINE_MEMMAP_BAD_MEMORY:
strcpy(type, "BAD_MEMORY");
break;
case LIMINE_MEMMAP_BOOTLOADER_RECLAIMABLE:
strcpy(type, "BOOTLOADER_RECLAIMABLE");
break;
case LIMINE_MEMMAP_KERNEL_AND_MODULES:
strcpy(type, "KERNEL_AND_MODULES");
break;
case LIMINE_MEMMAP_FRAMEBUFFER:
strcpy(type, "FRAMEBUFFER");
break;
default:
strcpy(type, "UNKNOWN");
break;
}
DEBUG("entry %u: [%016x | %u bytes] - %s", i, entry->base, entry->length, type);
}
}

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@@ -8,4 +8,6 @@ void* memset(void* s, int c, size_t n);
void* memmove(void *dest, const void* src, size_t n);
int memcmp(const void* s1, const void* s2, size_t n);
void memmap_display(struct limine_memmap_response* response);
#endif

16
src/mem/paging/paging.h Normal file
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@@ -0,0 +1,16 @@
#ifndef PAGING_PMM_H
#define PAGING_PMM_H
/*
We are going to use a bitmap, consisting of an array of uint64_t
to represent pages for the PMM (physical memory manager).
Bit set (1) = page used
Bit clear (0) = page free
*/
#define PAGE_SIZE 4096
#define BITS_PER_ROW 64
#endif

17
src/mem/paging/pmm.c Normal file
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@@ -0,0 +1,17 @@
// OMG here we are. I'm cooked.
/*
pmm - Physical Memory Manager
will manage 4kb pages physically
it will probably need to get some info from Limine,
to see which pages are used by kernel/bootloader/mmio/fb etc.
*/
#include "paging.h"
/*
First we'll have to discover the physical memory layout,
and for that we can use a Limine request.
*/
uint64_t pages_bitmap[];

6
src/string/string.c Normal file
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@@ -0,0 +1,6 @@
char* strcpy(char *dest, const char *src)
{
char *temp = dest;
while((*dest++ = *src++));
return temp;
}

6
src/string/string.h Normal file
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@@ -0,0 +1,6 @@
#ifndef STRING_H
#define STRING_H
char *strcpy(char *dest, const char *src);
#endif