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>
21 .globl ASM_PFX(CEntryPoint)
22 .globl ASM_PFX(_ModuleEntryPoint)
24 ASM_PFX(_ModuleEntryPoint):
27 mrc p15, 0, r0, c1, c0, 1 // read Auxiliary Control Register
28 bic r0, r0, #0x00000002 // disable L2 cache
29 mcr p15, 0, r0, c1, c0, 1 // store Auxiliary Control Register
31 //Enable Strict alignment checking & Instruction cache
32 mrc p15, 0, r0, c1, c0, 0
33 bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
34 bic r0, r0, #0x00000005 /* clear bits 0, 2 (---- -C-M) */
35 orr r0, r0, #0x00000002 /* set bit 1 (A) Align */
36 orr r0, r0, #0x00001000 /* set bit 12 (I) enable I-Cache */
37 mcr p15, 0, r0, c1, c0, 0
39 // Enable NEON register in case folks want to use them for optimizations (CopyMem)
40 mrc p15, 0, r0, c1, c0, 2
41 orr r0, r0, #0x00f00000 // Enable VPF access (V* instructions)
42 mcr p15, 0, r0, c1, c0, 2
43 mov r0, #0x40000000 // Set EN bit in FPEXC
44 mcr p10,#0x7,r0,c8,c0,#0 // msr FPEXC,r0 in ARM assembly
47 // Set CPU vectors to start of DRAM
48 LoadConstantToReg (FixedPcdGet32(PcdCpuVectorBaseAddress) ,r0) // Get vector base
49 mcr p15, 0, r0, c12, c0, 0
50 isb // Sync changes to control registers
52 // Fill vector table with branchs to current pc (jmp $)
53 ldr r1, ShouldNeverGetHere
61 /* before we call C code, lets setup the stack pointer in internal RAM */
65 // Set stack based on PCD values. Need to do it this way to make C code work
66 // when it runs from FLASH.
68 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r2) /* stack base arg2 */
69 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r3) /* stack size arg3 */
72 //Enter SVC mode and set up SVC stack pointer
73 mov r0,#0x13|0x80|0x40
78 LoadConstantToReg (FixedPcdGet32(PcdMemorySize) ,r1) /* memory size arg1 */
79 LoadConstantToReg (FixedPcdGet32(PcdMemoryBase) ,r0) /* memory size arg0 */
80 blx ASM_PFX(CEntryPoint) /* Assume C code is thumb */
83 /* _CEntryPoint should never return */