x86_64: initialise memblock using e820

arch/x86_64/e820.c

@@ -0,0 +1,56 @@
+#include "socks/types.h"
+#include <socks/memblock.h>
+#include <socks/printk.h>
+#include <socks/util.h>
+#include <arch/e820.h>
+
+void e820_scan(multiboot_memory_map_t *mmap, size_t len)
+{
+	size_t mem_total = 0, mem_reserved = 0;
+
+	multiboot_memory_map_t *entry = NULL;
+	for (size_t i = 0; i < len; i += sizeof *entry) {
+		entry = (void *)((char *)mmap + i);
+
+		int reserved = 1;
+		const char *type = "unknown";
+		switch (entry->type) {
+		case MULTIBOOT_MEMORY_AVAILABLE:
+			type = "available";
+			reserved = 0;
+			break;
+		case MULTIBOOT_MEMORY_RESERVED:
+			type = "reserved";
+			break;
+		case MULTIBOOT_MEMORY_ACPI_RECLAIMABLE:
+			type = "acpi";
+			break;
+		case MULTIBOOT_MEMORY_NVS:
+			type = "nvs";
+			break;
+		case MULTIBOOT_MEMORY_BADRAM:
+			type = "bad";
+			break;
+		default:
+			break;
+		}
+
+		printk("e820: [mem 0x%016llx-0x%016llx] %s",
+		       entry->addr, entry->addr + entry->len - 1, type);
+
+		memblock_add(entry->addr, entry->len);
+
+		if (reserved) {
+			memblock_reserve(entry->addr, entry->len);
+			mem_reserved += entry->len;
+		}
+		
+		mem_total += entry->len;
+	}
+
+	char str_mem_total[64], str_mem_reserved[64];
+	data_size_to_string(mem_total, str_mem_total, sizeof str_mem_total);
+	data_size_to_string(mem_reserved, str_mem_reserved, sizeof str_mem_reserved);
+
+	printk("e820: total memory: %s, hw reserved: %s", str_mem_total, str_mem_reserved);
+}

arch/x86_64/include/arch/e820.h

@@ -0,0 +1,9 @@
+#ifndef ARCH_E820_H_
+#define ARCH_E820_H_
+
+#include <stddef.h>
+#include <arch/multiboot.h>
+
+extern void e820_scan(multiboot_memory_map_t *mmap, size_t len);
+
+#endif

arch/x86_64/init.c

@@ -1,21 +1,51 @@
+#include "socks/types.h"
+#include <arch/e820.h>
 #include <socks/init.h>
+#include <socks/memblock.h>
+#include <socks/vm.h>
+#include <socks/printk.h>
 #include <socks/machine/cpu.h>
 #include <arch/vgacon.h>
 
+#define PTR32(x) ((void *)((uintptr_t)(x)))
+
 static ml_cpu_block g_bootstrap_cpu = {0};
 
+/* start and end of kernel image (physical addresses) */
+extern char __pstart[], __pend[];
+
 static void bootstrap_cpu_init(void)
 {
 	ml_cpu_block_init(&g_bootstrap_cpu);
 	ml_cpu_block_use(&g_bootstrap_cpu);
 }
 
+static void early_vm_init(void)
+{
+	uintptr_t alloc_start = VM_KERNEL_VOFFSET;
+	/* boot code mapped 2 GiB of memory from
+	   VM_KERNEL_VOFFSET */
+	uintptr_t alloc_end = VM_KERNEL_VOFFSET + 0x7fffffff;
+
+	memblock_init(alloc_start, alloc_end, VM_KERNEL_VOFFSET);
+	printk("memblock: allocating from [0x%llx-0x%llx]", alloc_start, alloc_end);
+
+	memblock_reserve(0x00, (uintptr_t)__pend);
+	printk("memblock: reserved bios+kernel at [0x%016llx-0x%016llx]", 0, (uintptr_t)__pend);
+}
+
 int ml_init(uintptr_t arg)
 {
+	multiboot_info_t *mb = (multiboot_info_t *)arg;
+	
 	bootstrap_cpu_init();
 	vgacon_init();
 
 	print_kernel_banner();
 
+	early_vm_init();
+
+	e820_scan(PTR32(mb->mmap_addr), mb->mmap_length);
+
 	return 0;
 }

arch/x86_64/layout.ld

@@ -17,6 +17,9 @@ SECTIONS {
 
     . += KERNEL_VMA;
 
+    __start = .;
+    __pstart = . - KERNEL_VMA;
+
     .text ALIGN(4K) : AT(ADDR(.text) - KERNEL_VMA)
     {
         *(.text)
@@ -47,7 +50,8 @@ SECTIONS {
         *(COMMON)
    }
 
-   _end = .;
+   __end = .;
+   __pend = . - KERNEL_VMA;
 
    /DISCARD/ :
    {

init/main.c

@@ -6,6 +6,8 @@
 
 extern unsigned long get_rflags(void);
 
+extern char __pstart[], __pend[];
+
 void print_kernel_banner(void)
 {
 	printk("Socks kernel version " BUILD_ID);
@@ -14,5 +16,6 @@ void print_kernel_banner(void)
 void kernel_init(uintptr_t arg)
 {
 	ml_init(arg);
+	
 	ml_halt_cpu();
 }