From 7ac2301d899be25b5e51d138fdb227ed0dbdca2d Mon Sep 17 00:00:00 2001
From: Michal Idziorek <m.i@gmx.at>
Date: Thu, 7 Aug 2014 22:02:20 +0200
Subject: physical memory allocation and fixed some bugs

---
 kernel/mem.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 98 insertions(+), 14 deletions(-)

(limited to 'kernel/mem.c')

diff --git a/kernel/mem.c b/kernel/mem.c
index 1bb4109..e1253b1 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -9,12 +9,16 @@
 //! block alignment
 #define PMMNGR_BLOCK_ALIGN	PMMNGR_BLOCK_SIZE
 
+#define MEM_BITMAP_SIZE 32768
+//#define MEM_BITMAP_SIZE 327
+
 // memory map bit array. Each bit represents a memory block
-static uint32_t	_mmngr_memory_map[129*1024];
+//uint32_t _mmngr_memory_map[MEM_BITMAP_SIZE];
+uint32_t *_mmngr_memory_map;
+
 static uint32_t mem_free_blocks;
 
 // bit funcs!
-
 void mmap_set(int bit) 
 {
       _mmngr_memory_map[bit / 32] |= (1 << (bit % 32));
@@ -30,18 +34,19 @@ int  mmap_test(int bit)
      return _mmngr_memory_map[bit / 32] &  (1 << (bit % 32));
 }
 
-///
-
-int mmap_first_free () {
+//
+int mmap_first_free () 
+{
  
     //! find the first free bit
     uint32_t i;
     int j;
 
-
-    for (i=0; i< 128 ; i++)
+    for (i=0; i< MEM_BITMAP_SIZE ; i++)
 	if (_mmngr_memory_map[i] != 0xffffffff)
-	    for (j=0; j<32; j++) {		//! test each bit in the dword
+	    for (j=0; j<32; j++) 
+	    {		
+		//! test each bit in the dword
  
 		int bit = 1 << j;
 		if (! (_mmngr_memory_map[i] & bit) )
@@ -49,17 +54,21 @@ int mmap_first_free () {
 	    }
  
     return -1;
+
 }
 
-void pmmngr_init () {
- 
+void pmmngr_init () 
+{
     //! By default, all of memory is in use
     //    memset (_mmngr_memory_map, 0xf, 128 );
     int i;
-    for(i=0;i++;i<128*1024)
+
+    for(i=0;i<MEM_BITMAP_SIZE;i++)
     {
 	_mmngr_memory_map[i]=0xffffffff;
     }
+
+
 }
 
 void pmmngr_init_region (uint32_t  base, uint32_t size)
@@ -87,6 +96,79 @@ void pmmngr_init_region (uint32_t  base, uint32_t size)
     //mmap_set (0);	//first block is always set. This insures allocs cant be 0
 }
 
+void* pmmngr_alloc_block () 
+{
+
+    int frame = mmap_first_free ();
+ 
+    if (frame == -1)
+    {
+	scr_put_string_nl("OUT OF MEM!");
+	return 0;	//out of memory
+    }
+
+//    scr_put_string_nl("MEM ALLOC OK!");
+//    scr_put_hex32(frame);
+ //   scr_put_string_nl("");
+ 
+    mmap_set (frame);
+ 
+    uint32_t addr = frame * PMMNGR_BLOCK_SIZE;
+    mem_free_blocks--;
+ 
+    return (void*)addr;
+}
+
+void pmmngr_free_block (void* p) {
+ 
+    uint32_t addr = (uint32_t*)p;
+    int frame = addr / PMMNGR_BLOCK_SIZE;
+ 
+    if(mmap_test(frame))
+    {
+	mmap_unset (frame);
+	mem_free_blocks++;
+    }
+ 
+}
+
+void mem_test_2()
+{
+    //crossing 512MB boundary! 
+    // (do not do this in real, coz it probably is reserved)
+    //mem_test(0x1fee1000,0x2000f000,0x800);
+
+    int cnt=-1;
+    uint32_t *addr;
+    uint32_t *lastaddr;
+
+    do{
+	lastaddr=addr;
+	addr=pmmngr_alloc_block();
+	cnt++;
+    }while(addr!=0);
+
+
+    scr_put_string("no mem after : ");
+    scr_put_hex32(cnt);
+    scr_put_string_nl("");
+
+    pmmngr_free_block(lastaddr);
+
+
+    cnt=-1;
+    do{
+	lastaddr=addr;
+	addr=pmmngr_alloc_block();
+	cnt++;
+    }while(addr!=0);
+
+
+    scr_put_string("no mem after : ");
+    scr_put_hex32(cnt);
+    scr_put_string_nl("");
+}
+
 void mem_test(int start, int end, int steps)
 {
     int *p=start;
@@ -107,7 +189,10 @@ void mem_test(int start, int end, int steps)
 
 void mem_init(uint16_t *memmap)
 {
+
+    _mmngr_memory_map=0x9000;
     mem_free_blocks=0;
+    pmmngr_init ();
 
     // count available memory
     uint32_t avail_mem=0;
@@ -153,9 +238,8 @@ void mem_init(uint16_t *memmap)
     scr_put_hex(mem_free_blocks&0xffff);
     scr_put_string_nl("");
 
-    //crossing 512MB boundary! 
-    // (do not do this in real, coz it probably is reserved)
-    //mem_test(0x1fee1000,0x2000f000,0x800);
+
+
 
 }
 
-- 
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