blob: 63174d4b84370287d304bd37415e54b59478cc8b [file] [log] [blame]
Vishal Bhoj82c80712015-12-15 21:13:33 +05301//------------------------------------------------------------------------------
2//
3// Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
4//
5// This program and the accompanying materials
6// are licensed and made available under the terms and conditions of the BSD License
7// which accompanies this distribution. The full text of the license may be found at
8// http://opensource.org/licenses/bsd-license.php
9//
10// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12//
13//------------------------------------------------------------------------------
14
15#include <AsmMacroIoLib.h>
16#include <Library/PcdLib.h>
17#include <AutoGen.h>
18 INCLUDE AsmMacroIoLib.inc
19
20 IMPORT CEntryPoint
21 EXPORT _ModuleEntryPoint
22
23 PRESERVE8
24 AREA ModuleEntryPoint, CODE, READONLY
25
26
27_ModuleEntryPoint
28
29 //Disable L2 cache
30 mrc p15, 0, r0, c1, c0, 1 // read Auxiliary Control Register
31 bic r0, r0, #0x00000002 // disable L2 cache
32 mcr p15, 0, r0, c1, c0, 1 // store Auxiliary Control Register
33
34 //Enable Strict alignment checking & Instruction cache
35 mrc p15, 0, r0, c1, c0, 0
36 bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
37 bic r0, r0, #0x00000005 /* clear bits 0, 2 (---- -C-M) */
38 orr r0, r0, #0x00000002 /* set bit 1 (A) Align */
39 orr r0, r0, #0x00001000 /* set bit 12 (I) enable I-Cache */
40 mcr p15, 0, r0, c1, c0, 0
41
42 // Enable NEON register in case folks want to use them for optimizations (CopyMem)
43 mrc p15, 0, r0, c1, c0, 2
44 orr r0, r0, #0x00f00000 // Enable VPF access (V* instructions)
45 mcr p15, 0, r0, c1, c0, 2
46 mov r0, #0x40000000 // Set EN bit in FPEXC
47 msr FPEXC,r0
48
49 // Set CPU vectors to start of DRAM
50 LoadConstantToReg (FixedPcdGet32(PcdCpuVectorBaseAddress) ,r0) // Get vector base
51 mcr p15, 0, r0, c12, c0, 0
52 isb // Sync changes to control registers
53
54 // Fill vector table with branchs to current pc (jmp $)
55 ldr r1, ShouldNeverGetHere
56 movs r2, #0
57FillVectors
58 str r1, [r0, r2]
59 adds r2, r2, #4
60 cmp r2, #32
61 bne FillVectors
62
63 /* before we call C code, lets setup the stack pointer in internal RAM */
64stack_pointer_setup
65
66 //
67 // Set stack based on PCD values. Need to do it this way to make C code work
68 // when it runs from FLASH.
69 //
70 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r2) // stack base arg2
71 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r3) // stack size arg3
72 add r4, r2, r3
73
74 //Enter SVC mode and set up SVC stack pointer
75 mov r5,#0x13|0x80|0x40
76 msr CPSR_c,r5
77 mov r13,r4
78
79 // Call C entry point
80 LoadConstantToReg (FixedPcdGet32(PcdMemorySize) ,r1) // memory size arg1
81 LoadConstantToReg (FixedPcdGet32(PcdMemoryBase) ,r0) // memory start arg0
82 blx CEntryPoint // Assume C code is thumb
83
84ShouldNeverGetHere
85 /* _CEntryPoint should never return */
86 b ShouldNeverGetHere
87
88 END
89