2 * Physical memory allocation
3 * Copyright (c) 2001,2003,2004 David H. Hovemeyer <daveho@cs.umd.edu>
4 * Copyright (c) 2003, Jeffrey K. Hollingsworth <hollings@cs.umd.edu>
5 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
6 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
9 * This is free software. You are permitted to use,
10 * redistribute, and modify it as specified in the file "COPYING".
13 #include <geekos/defs.h>
14 #include <geekos/ktypes.h>
15 #include <geekos/kassert.h>
16 #include <geekos/bootinfo.h>
17 #include <geekos/gdt.h>
18 #include <geekos/screen.h>
19 #include <geekos/int.h>
20 #include <geekos/malloc.h>
21 #include <geekos/string.h>
22 #include <geekos/mem.h>
24 #include <geekos/serial.h>
25 #include <geekos/debug.h>
28 /* ----------------------------------------------------------------------
30 * ---------------------------------------------------------------------- */
33 * List of Page structures representing each page of physical memory.
35 struct Page* g_pageList;
38 ulong_t g_ramdiskImage;
39 ulong_t s_ramdiskSize;
43 * Number of pages currently available on the freelist.
45 uint_t g_freePageCount = 0;
50 * the disgusting way to get at the memory assigned to a VM
52 extern ulong_t vm_range_start;
53 extern ulong_t vm_range_end;
54 extern ulong_t guest_kernel_start;
55 extern ulong_t guest_kernel_end;
59 /* ----------------------------------------------------------------------
60 * Private data and functions
61 * ---------------------------------------------------------------------- */
66 extern int debugFaults;
67 #define Debug(args...) if (debugFaults) Print(args)
70 * List of pages available for allocation.
72 static struct Page_List s_freeList;
75 * Total number of physical pages.
77 int unsigned s_numPages;
83 * Add a range of pages to the inventory of physical memory.
85 static void Add_Page_Range(ulong_t start, ulong_t end, int flags)
89 PrintBoth("Start: %u (0x%x), End: %u(0x%x) (Type=0x%.4x)\n", (unsigned int)start, start, (unsigned int)end, end, flags);
91 KASSERT(Is_Page_Multiple(start));
92 KASSERT(Is_Page_Multiple(end));
95 //Print("Adding %lu pages\n", (end - start) / PAGE_SIZE);
97 for (addr = start; addr < end; addr += PAGE_SIZE) {
98 // Print("Adding Page at %u\n", (unsigned int)addr);
99 struct Page *page = Get_Page(addr);
103 if (flags == PAGE_AVAIL) {
104 /* Add the page to the freelist */
105 Add_To_Back_Of_Page_List(&s_freeList, page);
107 /* Update free page count */
110 Set_Next_In_Page_List(page, 0);
111 Set_Prev_In_Page_List(page, 0);
115 // Print("%d pages now in freelist\n", g_freePageCount);
119 /* ----------------------------------------------------------------------
121 * ---------------------------------------------------------------------- */
124 * The linker defines this symbol to indicate the end of
125 * the executable image.
130 * Initialize memory management data structures.
131 * Enables the use of Alloc_Page() and Free_Page() functions.
133 void Init_Mem(struct Boot_Info* bootInfo)
135 ulong_t numPages = bootInfo->memSizeKB >> 2;
136 ulong_t endOfMem = numPages * PAGE_SIZE;
137 unsigned numPageListBytes = sizeof(struct Page) * numPages;
138 ulong_t pageListAddr;
147 g_ramdiskImage = bootInfo->ramdisk_image;
148 s_ramdiskSize = bootInfo->ramdisk_size;
154 KASSERT(bootInfo->memSizeKB > 0);
158 * Before we do anything, switch from setup.asm's temporary GDT
159 * to the kernel's permanent GDT.
164 PrintBoth("Total Memory Size: %u MBytes\n", bootInfo->memSizeKB/1024);
165 PrintBoth("Page List (at 0x%x) Size: %u bytes\n", &s_freeList, numPageListBytes);
169 * bios area (1 page reserved)
170 * kernel_thread_obj (1 page)
171 * kernel_stack (1 page)
174 * ISA_HOLE_START - ISA_HOLE_END: hardware
176 * start - end: kernel
177 * VM Guest (variable pages)
179 * Page List (variable pages)
180 * Available Memory for VMM (4096 pages)
181 * Ramdisk //Zheng 08/03/2008
182 * VM Memory (everything else)
185 //kernEnd = Round_Up_To_Page((ulong_t)&end);
186 kernEnd = (ulong_t)&end;
188 PrintBoth("Kernel End=%lx\n", kernEnd);
191 /* ************************************************************************************** */
192 /* If we have dynamic loading of the guest kernel, we should put the relocation code here */
193 /* ************************************************************************************** */
195 kernEnd = Round_Up_To_Page(kernEnd);
197 heapEnd = Round_Up_To_Page(heapAddr + KERNEL_HEAP_SIZE);
198 pageListAddr = heapEnd;
199 pageListEnd = Round_Up_To_Page(pageListAddr + numPageListBytes);
200 /* Global variables */
201 // These must be set before we can call Add_Page_Range..
202 g_pageList = (struct Page*) pageListAddr;
203 s_numPages = numPages;
205 vmmMemEnd = Round_Up_To_Page(pageListEnd + VMM_AVAIL_MEM_SIZE);
210 * copy the ramdisk to this area
213 initrdAddr = vmmMemEnd;
214 initrdEnd = Round_Up_To_Page(initrdAddr + s_ramdiskSize);
215 PrintBoth("mem.c(%d) Move ramdisk(%dB) from %x to %x", __LINE__, s_ramdiskSize, g_ramdiskImage, initrdAddr);
216 memcpy((ulong_t *)initrdAddr, (ulong_t *)g_ramdiskImage, s_ramdiskSize);
217 PrintBoth(" done\n");
218 PrintBoth("mem.c(%d) Set 0 to unused bytes in the last ramdisk page from %x to %x", __LINE__, initrdAddr+s_ramdiskSize, initrdEnd);
219 memset((ulong_t *)initrdAddr+s_ramdiskSize, 0, initrdEnd-(initrdAddr+s_ramdiskSize));
220 PrintBoth(" done\n");
224 vm_range_start = initrdEnd;
225 vm_range_end = endOfMem;
229 * the disgusting way to get at the memory assigned to a VM
232 vm_range_start = vmmMemEnd;
233 vm_range_end = endOfMem;
237 Add_Page_Range(0, PAGE_SIZE, PAGE_UNUSED); // BIOS area
238 Add_Page_Range(PAGE_SIZE, PAGE_SIZE * 3, PAGE_ALLOCATED); // Intial kernel thread obj + stack
239 Add_Page_Range(PAGE_SIZE * 3, ISA_HOLE_START, PAGE_AVAIL); // Available space
240 Add_Page_Range(ISA_HOLE_START, ISA_HOLE_END, PAGE_HW); // Hardware ROMs
241 Add_Page_Range(KERNEL_START_ADDR, kernEnd, PAGE_KERN); // VMM Kernel
242 // Add_Page_Range(guest_kernel_start, guestEnd, PAGE_VM); // Guest kernel location
243 Add_Page_Range(heapAddr, heapEnd, PAGE_HEAP); // Heap
244 Add_Page_Range(pageListAddr, pageListEnd, PAGE_KERN); // Page List
245 Add_Page_Range(pageListEnd, vmmMemEnd, PAGE_AVAIL); // Available VMM memory
251 Add_Page_Range(vmmMemEnd, initrdEnd, PAGE_ALLOCATED); //Ramdisk memory area
252 // Add_Page_Range(vmmMemEnd, endOfMem, PAGE_VM); // Memory allocated to the VM
253 // Until we get a more intelligent memory allocator
254 Add_Page_Range(initrdEnd, endOfMem, PAGE_AVAIL); // Memory allocated to the VM
256 Add_Page_Range(vmmMemEnd, endOfMem, PAGE_AVAIL); // Memory allocated to the VM
259 /* Initialize the kernel heap */
260 Init_Heap(heapAddr, KERNEL_HEAP_SIZE);
262 PrintBoth("%uKB memory detected, %u pages in freelist, %d bytes in kernel heap\n",
263 bootInfo->memSizeKB, g_freePageCount, KERNEL_HEAP_SIZE);
265 PrintBoth("Memory Layout:\n");
266 PrintBoth("%x to %x - BIOS AREA\n", 0, PAGE_SIZE - 1);
267 PrintBoth("%x to %x - KERNEL_THREAD_OBJ\n", PAGE_SIZE, PAGE_SIZE * 2 - 1);
268 PrintBoth("%x to %x - KERNEL_STACK\n", PAGE_SIZE * 2, PAGE_SIZE * 3 - 1);
269 PrintBoth("%lx to %x - FREE\n", PAGE_SIZE * 3, ISA_HOLE_START - 1);
270 PrintBoth("%x to %x - ISA_HOLE\n", ISA_HOLE_START, ISA_HOLE_END - 1);
271 PrintBoth("%x to %x - KERNEL CODE + VM_KERNEL\n", KERNEL_START_ADDR, kernEnd - 1);
272 // PrintBoth("%x to %x - VM_KERNEL\n", kernEnd, guestEnd - 1);
273 PrintBoth("%x to %x - KERNEL HEAP\n", heapAddr, heapEnd - 1);
274 PrintBoth("%lx to %lx - PAGE LIST\n", pageListAddr, pageListEnd - 1);
275 PrintBoth("%lx to %x - FREE\n", pageListEnd, vmmMemEnd - 1);
281 PrintBoth("%lx to %x - RAMDISK\n", vmmMemEnd, initrdEnd - 1);
283 PrintBoth("%lx to %x - GUEST_MEMORY (also free)\n", initrdEnd, endOfMem - 1);
285 PrintBoth("%lx to %x - GUEST_MEMORY (also free)\n", vmmMemEnd, endOfMem - 1);
290 * Initialize the .bss section of the kernel executable image.
294 extern char BSS_START, BSS_END;
296 /* Fill .bss with zeroes */
297 memset(&BSS_START, '\0', &BSS_END - &BSS_START);
298 // screen is not inited yet - PAD
299 // PrintBoth("BSS Inited, BSS_START=%x, BSS_END=%x\n",BSS_START,BSS_END);
303 * Allocate a page of physical memory.
305 void* Alloc_Page(void)
310 bool iflag = Begin_Int_Atomic();
312 /* See if we have a free page */
313 if (!Is_Page_List_Empty(&s_freeList)) {
314 /* Remove the first page on the freelist. */
315 page = Get_Front_Of_Page_List(&s_freeList);
316 KASSERT((page->flags & PAGE_ALLOCATED) == 0);
317 Remove_From_Front_Of_Page_List(&s_freeList);
319 /* Mark page as having been allocated. */
320 page->flags |= PAGE_ALLOCATED;
322 result = (void*) Get_Page_Address(page);
325 End_Int_Atomic(iflag);
331 * Free a page of physical memory.
333 void Free_Page(void* pageAddr)
335 ulong_t addr = (ulong_t) pageAddr;
339 iflag = Begin_Int_Atomic();
341 KASSERT(Is_Page_Multiple(addr));
343 /* Get the Page object for this page */
344 page = Get_Page(addr);
345 KASSERT((page->flags & PAGE_ALLOCATED) != 0);
347 /* Clear the allocation bit */
348 page->flags &= ~(PAGE_ALLOCATED);
350 /* Put the page back on the freelist */
351 Add_To_Back_Of_Page_List(&s_freeList, page);
354 End_Int_Atomic(iflag);