1 | /* |
---|
2 | * This routine is an implementation of the bsp_get_work_area() |
---|
3 | * that can be used by all m68k BSPs following linkcmds conventions |
---|
4 | * regarding heap, stack, and workspace allocation. |
---|
5 | * |
---|
6 | * COPYRIGHT (c) 1989-2008. |
---|
7 | * On-Line Applications Research Corporation (OAR). |
---|
8 | * |
---|
9 | * The license and distribution terms for this file may be |
---|
10 | * found in the file LICENSE in this distribution or at |
---|
11 | * http://www.rtems.com/license/LICENSE. |
---|
12 | * |
---|
13 | * $Id$ |
---|
14 | */ |
---|
15 | |
---|
16 | #include <bsp.h> |
---|
17 | #include <bsp/bootcard.h> |
---|
18 | |
---|
19 | /* |
---|
20 | * These are provided by the linkcmds. |
---|
21 | */ |
---|
22 | extern char WorkAreaBase[]; |
---|
23 | extern char HeapSize[]; |
---|
24 | extern char RamSize[]; |
---|
25 | |
---|
26 | /* rudimentary multiboot info */ |
---|
27 | struct multiboot_info { |
---|
28 | uint32_t flags; /* start.S only raises flags for items actually */ |
---|
29 | /* saved; this allows us to check for the size */ |
---|
30 | /* of the data structure. */ |
---|
31 | uint32_t mem_lower; /* avail kB in lower memory */ |
---|
32 | uint32_t mem_upper; /* avail kB in lower memory */ |
---|
33 | /* ... (unimplemented) */ |
---|
34 | }; |
---|
35 | |
---|
36 | extern struct multiboot_info _boot_multiboot_info; |
---|
37 | |
---|
38 | /* |
---|
39 | * Board's memory size easily be overridden by application. |
---|
40 | */ |
---|
41 | uint32_t bsp_mem_size = 0; |
---|
42 | |
---|
43 | /* Size of stack used during initialization. Defined in 'start.s'. */ |
---|
44 | extern uint32_t _stack_size; |
---|
45 | |
---|
46 | /* Address of start of free memory. */ |
---|
47 | uintptr_t rtemsFreeMemStart; |
---|
48 | |
---|
49 | |
---|
50 | void bsp_size_memory(void) |
---|
51 | { |
---|
52 | uintptr_t topAddr; |
---|
53 | uintptr_t lowest; |
---|
54 | uint32_t val; |
---|
55 | int i; |
---|
56 | |
---|
57 | /* set the value of start of free memory. */ |
---|
58 | rtemsFreeMemStart = (uint32_t)WorkAreaBase + _stack_size; |
---|
59 | |
---|
60 | /* Place RTEMS workspace at beginning of free memory. */ |
---|
61 | |
---|
62 | if (rtemsFreeMemStart & (CPU_ALIGNMENT - 1)) /* not aligned => align it */ |
---|
63 | rtemsFreeMemStart = (rtemsFreeMemStart+CPU_ALIGNMENT) & ~(CPU_ALIGNMENT-1); |
---|
64 | |
---|
65 | /* find the lowest 1M boundary to probe */ |
---|
66 | lowest = ((rtemsFreeMemStart + (1<<20)) >> 20) + 1; |
---|
67 | if ( lowest < 2 ) |
---|
68 | lowest = 2; |
---|
69 | |
---|
70 | /* The memory detection algorithm is very crude; try |
---|
71 | * to use multiboot info, if possible (set from start.S) |
---|
72 | */ |
---|
73 | if ( ((uintptr_t)RamSize == (uintptr_t) 0xFFFFFFFF) && |
---|
74 | (_boot_multiboot_info.flags & 1) && |
---|
75 | _boot_multiboot_info.mem_upper ) { |
---|
76 | bsp_mem_size = _boot_multiboot_info.mem_upper * 1024; |
---|
77 | } |
---|
78 | |
---|
79 | if ( (uintptr_t) RamSize == (uintptr_t) 0xFFFFFFFF ) { |
---|
80 | /* |
---|
81 | * We have to dynamically size memory. Memory size can be anything |
---|
82 | * between no less than 2M and 2048M. |
---|
83 | * let us first write |
---|
84 | */ |
---|
85 | for (i=2048; i>=lowest; i--) { |
---|
86 | topAddr = i*1024*1024 - 4; |
---|
87 | *(volatile uint32_t*)topAddr = topAddr; |
---|
88 | } |
---|
89 | |
---|
90 | for(i=lowest; i<=2048; i++) { |
---|
91 | topAddr = i*1024*1024 - 4; |
---|
92 | val = *(uint32_t*)topAddr; |
---|
93 | if (val != topAddr) { |
---|
94 | break; |
---|
95 | } |
---|
96 | } |
---|
97 | |
---|
98 | topAddr = (i-1)*1024*1024 - 4; |
---|
99 | } else { |
---|
100 | topAddr = (uintptr_t) RamSize; |
---|
101 | } |
---|
102 | |
---|
103 | bsp_mem_size = topAddr; |
---|
104 | } |
---|
105 | /* |
---|
106 | * This method returns the base address and size of the area which |
---|
107 | * is to be allocated between the RTEMS Workspace and the C Program |
---|
108 | * Heap. |
---|
109 | */ |
---|
110 | void bsp_get_work_area( |
---|
111 | void **work_area_start, |
---|
112 | size_t *work_area_size, |
---|
113 | void **heap_start, |
---|
114 | size_t *heap_size |
---|
115 | ) |
---|
116 | { |
---|
117 | *work_area_start = (void *) rtemsFreeMemStart; |
---|
118 | *work_area_size = (uintptr_t) bsp_mem_size - (uintptr_t) rtemsFreeMemStart; |
---|
119 | *heap_start = BSP_BOOTCARD_HEAP_USES_WORK_AREA; |
---|
120 | *heap_size = (size_t) HeapSize; |
---|
121 | |
---|
122 | #if 0 |
---|
123 | printk( "WorkArea Base = %p\n", *work_area_start ); |
---|
124 | printk( "WorkArea Size = 0x%08x\n", *work_area_size ); |
---|
125 | printk( "C Program Heap Base = %p\n", *heap_start ); |
---|
126 | printk( "C Program Heap Size = 0x%08x\n", *heap_size ); |
---|
127 | #endif |
---|
128 | } |
---|