First steps: getting memory map from Limine request and looking at it

src/mem/misc/utils.c

@@ -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);
+	}
 }

src/mem/misc/utils.h

@@ -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

src/mem/paging/paging.h

@@ -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

src/mem/paging/pmm.c

@@ -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[];