1 //------------------------------------------------------------------------------
3 // Copyright (c) 2008-2009 Apple Inc. All rights reserved.
5 // All rights reserved. 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
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.
13 //------------------------------------------------------------------------------
15 #include <AsmMacroIoLib.h>
16 #include <Library/PcdLib.h>
18 INCLUDE AsmMacroIoLib.inc
21 EXPORT _ModuleEntryPoint
24 AREA ModuleEntryPoint, CODE, READONLY
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
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
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
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
54 // Fill vector table with branchs to current pc (jmp $)
55 ldr r1, ShouldNeverGetHere
63 /* before we call C code, lets setup the stack pointer in internal RAM */
67 // Set stack based on PCD values. Need to do it this way to make C code work
68 // when it runs from FLASH.
70 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r2) // stack base arg2
71 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r3) // stack size arg3
74 //Enter SVC mode and set up SVC stack pointer
75 mov r5,#0x13|0x80|0x40
80 LoadConstantToReg (FixedPcdGet32(PcdMemorySize) ,r1) // memory size arg1
81 LoadConstantToReg (FixedPcdGet32(PcdMemoryBase) ,r0) // memory start arg0
82 blx CEntryPoint // Assume C code is thumb
85 /* _CEntryPoint should never return */