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1//
2//  Copyright (c) 2011-2015, ARM Limited. All rights reserved.
3//
4//  This program and the accompanying materials
5//  are licensed and made available under the terms and conditions of the BSD License
6//  which accompanies this distribution.  The full text of the license may be found at
7//  http://opensource.org/licenses/bsd-license.php
8//
9//  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10//  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11//
12//
13
14#include <AsmMacroIoLibV8.h>
15
16ASM_FUNC(_ModuleEntryPoint)
17  // Do early platform specific actions
18  bl    ASM_PFX(ArmPlatformPeiBootAction)
19
20  // Get ID of this CPU in Multicore system
21  bl    ASM_PFX(ArmReadMpidr)
22  // Keep a copy of the MpId register value
23  mov   x10, x0
24
25_SetSVCMode:
26// Check if we can install the stack at the top of the System Memory or if we need
27// to install the stacks at the bottom of the Firmware Device (case the FD is located
28// at the top of the DRAM)
29_SystemMemoryEndInit:
30  ldr   x1, mSystemMemoryEnd
31
32_SetupStackPosition:
33  // r1 = SystemMemoryTop
34
35  // Calculate Top of the Firmware Device
36  MOV64 (x2, FixedPcdGet64(PcdFdBaseAddress))
37  MOV32 (x3, FixedPcdGet32(PcdFdSize) - 1)
38  sub   x3, x3, #1
39  add   x3, x3, x2      // x3 = FdTop = PcdFdBaseAddress + PcdFdSize
40
41  // UEFI Memory Size (stacks are allocated in this region)
42  MOV32 (x4, FixedPcdGet32(PcdSystemMemoryUefiRegionSize))
43
44  //
45  // Reserve the memory for the UEFI region (contain stacks on its top)
46  //
47
48  // Calculate how much space there is between the top of the Firmware and the Top of the System Memory
49  subs  x0, x1, x3   // x0 = SystemMemoryTop - FdTop
50  b.mi  _SetupStack  // Jump if negative (FdTop > SystemMemoryTop). Case when the PrePi is in XIP memory outside of the DRAM
51  cmp   x0, x4
52  b.ge  _SetupStack
53
54  // Case the top of stacks is the FdBaseAddress
55  mov   x1, x2
56
57_SetupStack:
58  // x1 contains the top of the stack (and the UEFI Memory)
59
60  // Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment
61  // one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the
62  // top of the memory space)
63  adds  x11, x1, #1
64  b.cs  _SetupOverflowStack
65
66_SetupAlignedStack:
67  mov   x1, x11
68  b     _GetBaseUefiMemory
69
70_SetupOverflowStack:
71  // Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE
72  // aligned (4KB)
73  and   x1, x1, ~EFI_PAGE_MASK
74
75_GetBaseUefiMemory:
76  // Calculate the Base of the UEFI Memory
77  sub   x11, x1, x4
78
79_GetStackBase:
80  // r1 = The top of the Mpcore Stacks
81  // Stack for the primary core = PrimaryCoreStack
82  MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
83  sub   x12, x1, x2
84
85  // Stack for the secondary core = Number of Cores - 1
86  MOV32 (x1, (FixedPcdGet32(PcdCoreCount) - 1) * FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
87  sub   x12, x12, x1
88
89  // x12 = The base of the MpCore Stacks (primary stack & secondary stacks)
90  mov   x0, x12
91  mov   x1, x10
92  //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
93  MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
94  MOV32 (x3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
95  bl    ASM_PFX(ArmPlatformStackSet)
96
97  // Is it the Primary Core ?
98  mov   x0, x10
99  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
100  cmp   x0, #1
101  bne   _PrepareArguments
102
103_PrepareArguments:
104  mov   x0, x10
105  mov   x1, x11
106  mov   x2, x12
107
108  // Move sec startup address into a data register
109  // Ensure we're jumping to FV version of the code (not boot remapped alias)
110  ldr   x4, =ASM_PFX(CEntryPoint)
111
112  // Jump to PrePiCore C code
113  //    x0 = MpId
114  //    x1 = UefiMemoryBase
115  //    x2 = StacksBase
116  blr   x4
117
118_NeverReturn:
119  b _NeverReturn
120