audk/ArmRealViewEbPkg/SecForPei/Arm/ModuleEntryPoint.S

82 lines
3.0 KiB
ArmAsm
Executable File

#------------------------------------------------------------------------------
#
# ARM EB Entry point. Reset vector in FV header will brach to
# _ModuleEntryPoint.
#
# We use crazy macros, like LoadConstantToReg, since Xcode assembler
# does not support = assembly syntax for ldr.
#
# Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
#
# This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
# which accompanies this distribution. The full text of the license may be found at
# http://opensource.org/licenses/bsd-license.php
#
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#
#------------------------------------------------------------------------------
#include <AsmMacroIoLib.h>
#include <Base.h>
#include <Library/PcdLib.h>
#include <ArmEb/ArmEb.h>
.text
.align 3
.globl ASM_PFX(CEntryPoint)
.globl ASM_PFX(_ModuleEntryPoint)
.globl ASM_PFX(StartupAddr)
ASM_PFX(CEntryPointData):
.word ASM_PFX(StartupAddr)
ASM_PFX(_ModuleEntryPoint):
// Turn off remapping NOR to 0. We can now use DRAM in low memory
// CAN'T DO THIS HERE -- BRANCH FROM RESET VECTOR IS RELATIVE AND REMAINS IN REMAPPED NOR
//MmioOr32 (0x10001000 ,BIT8) //EB_SP810_CTRL_BASE
// Enable NEON register in case folks want to use them for optimizations (CopyMem)
mrc p15, 0, r0, c1, c0, 2
orr r0, r0, #0x00f00000 // Enable VFP access (V* instructions)
mcr p15, 0, r0, c1, c0, 2
mov r0, #0x40000000 // Set EN bit in FPEXC
mcr p10,#0x7,r0,c8,c0,#0 // msr FPEXC,r0 in ARM assembly
// Set CPU vectors to 0 (which is currently flash)
LoadConstantToReg (FixedPcdGet32(PcdCpuVectorBaseAddress) ,r0) // Get vector base
mcr p15, 0, r0, c12, c0, 0
isb // Sync changes to control registers
//
// Set stack based on PCD values. Need to do it this way to make C code work
// when it runs from FLASH.
//
LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r0) // temp ram base arg 0 TODO: change "stackbase" to "temprambase"
LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r1) // temp ram size arg 1
lsr r3, r1, #1 // r4 = size of temp mem / 2
add r3, r3, r0 // r2 = temp ram base + r4
mov r13, r3 // result: stack pointer = temp ram base + (size of temp mem / 2)
// lr points to area in reset vector block containing PEI core address
ldr r2, [lr] // pei core arg 3
// move sec startup address into a data register
// ensure we're jumping to FV version of the code (not boot remapped alias)
ldr r5, ASM_PFX(CEntryPointData) // Extra level of indirection fixes Xcode relocation issue
ldr r4, [r5]
// jump to SEC C code
blx r4
ASM_PFX(ShouldNeverGetHere):
// _CEntryPoint should never return
b ASM_PFX(ShouldNeverGetHere)