1#------------------------------------------------------------------------------ 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 18.text 19.align 3 20 21.globl ASM_PFX(CEntryPoint) 22GCC_ASM_EXPORT(_ModuleEntryPoint) 23 24ASM_PFX(_ModuleEntryPoint): 25 26 //Disable L2 cache 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 30 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 38 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 45 46 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 51 52 // Fill vector table with branchs to current pc (jmp $) 53 ldr r1, ShouldNeverGetHere 54 movs r2, #0 55FillVectors: 56 str r1, [r0, r2] 57 adds r2, r2, #4 58 cmp r2, #32 59 bne FillVectors 60 61 /* before we call C code, lets setup the stack pointer in internal RAM */ 62stack_pointer_setup: 63 64 // 65 // Set stack based on PCD values. Need to do it this way to make C code work 66 // when it runs from FLASH. 67 // 68 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r2) /* stack base arg2 */ 69 LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r3) /* stack size arg3 */ 70 add r4, r2, r3 71 72 //Enter SVC mode and set up SVC stack pointer 73 mov r0,#0x13|0x80|0x40 74 msr CPSR_c,r0 75 mov r13,r4 76 77 // Call C entry point 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 */ 81 82ShouldNeverGetHere: 83 /* _CEntryPoint should never return */ 84 b ShouldNeverGetHere 85 86