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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#include <Base.h>
16#include <Library/PcdLib.h>
17#include <AutoGen.h>
18
19.text
20.align 3
21
22GCC_ASM_IMPORT(ArmPlatformIsPrimaryCore)
23GCC_ASM_IMPORT(ArmReadMpidr)
24GCC_ASM_IMPORT(ArmPlatformPeiBootAction)
25GCC_ASM_IMPORT(ArmPlatformStackSet)
26GCC_ASM_EXPORT(_ModuleEntryPoint)
27ASM_GLOBAL ASM_PFX(mSystemMemoryEnd)
28
29StartupAddr:                  .8byte ASM_PFX(CEntryPoint)
30ASM_PFX(mSystemMemoryEnd):    .8byte 0
31
32ASM_PFX(_ModuleEntryPoint):
33  // Do early platform specific actions
34  bl    ASM_PFX(ArmPlatformPeiBootAction)
35
36  // Get ID of this CPU in Multicore system
37  bl    ASM_PFX(ArmReadMpidr)
38  // Keep a copy of the MpId register value
39  mov   x10, x0
40
41_SetSVCMode:
42// Check if we can install the stack at the top of the System Memory or if we need
43// to install the stacks at the bottom of the Firmware Device (case the FD is located
44// at the top of the DRAM)
45_SystemMemoryEndInit:
46  ldr   x1, mSystemMemoryEnd
47
48  // Is mSystemMemoryEnd initialized?
49  cmp   x1, #0
50  bne   _SetupStackPosition
51
52  LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryBase), x1)
53  LoadConstantToReg (FixedPcdGet32(PcdSystemMemorySize), x2)
54  sub   x2, x2, #1
55  add   x1, x1, x2
56  // Update the global variable
57  adr   x2, mSystemMemoryEnd
58  str   x1, [x2]
59
60_SetupStackPosition:
61  // r1 = SystemMemoryTop
62
63  // Calculate Top of the Firmware Device
64  LoadConstantToReg (FixedPcdGet32(PcdFdBaseAddress), x2)
65  LoadConstantToReg (FixedPcdGet32(PcdFdSize), x3)
66  sub   x3, x3, #1
67  add   x3, x3, x2      // x3 = FdTop = PcdFdBaseAddress + PcdFdSize
68
69  // UEFI Memory Size (stacks are allocated in this region)
70  LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryUefiRegionSize), x4)
71
72  //
73  // Reserve the memory for the UEFI region (contain stacks on its top)
74  //
75
76  // Calculate how much space there is between the top of the Firmware and the Top of the System Memory
77  subs  x0, x1, x3   // x0 = SystemMemoryTop - FdTop
78  b.mi  _SetupStack  // Jump if negative (FdTop > SystemMemoryTop). Case when the PrePi is in XIP memory outside of the DRAM
79  cmp   x0, x4
80  b.ge  _SetupStack
81
82  // Case the top of stacks is the FdBaseAddress
83  mov   x1, x2
84
85_SetupStack:
86  // x1 contains the top of the stack (and the UEFI Memory)
87
88  // Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment
89  // one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the
90  // top of the memory space)
91  adds  x11, x1, #1
92  b.cs  _SetupOverflowStack
93
94_SetupAlignedStack:
95  mov   x1, x11
96  b     _GetBaseUefiMemory
97
98_SetupOverflowStack:
99  // Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE
100  // aligned (4KB)
101  LoadConstantToReg (EFI_PAGE_MASK, x11)
102  and   x11, x11, x1
103  sub   x1, x1, x11
104
105_GetBaseUefiMemory:
106  // Calculate the Base of the UEFI Memory
107  sub   x11, x1, x4
108
109_GetStackBase:
110  // r1 = The top of the Mpcore Stacks
111  // Stack for the primary core = PrimaryCoreStack
112  LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), x2)
113  sub   x12, x1, x2
114
115  // Stack for the secondary core = Number of Cores - 1
116  LoadConstantToReg (FixedPcdGet32(PcdCoreCount), x0)
117  sub   x0, x0, #1
118  LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), x1)
119  mul   x1, x1, x0
120  sub   x12, x12, x1
121
122  // x12 = The base of the MpCore Stacks (primary stack & secondary stacks)
123  mov   x0, x12
124  mov   x1, x10
125  //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
126  LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), x2)
127  LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), x3)
128  bl    ASM_PFX(ArmPlatformStackSet)
129
130  // Is it the Primary Core ?
131  mov   x0, x10
132  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
133  cmp   x0, #1
134  bne   _PrepareArguments
135
136_PrepareArguments:
137  mov   x0, x10
138  mov   x1, x11
139  mov   x2, x12
140
141  // Move sec startup address into a data register
142  // Ensure we're jumping to FV version of the code (not boot remapped alias)
143  ldr   x4, StartupAddr
144
145  // Jump to PrePiCore C code
146  //    x0 = MpId
147  //    x1 = UefiMemoryBase
148  //    x2 = StacksBase
149  blr   x4
150
151_NeverReturn:
152  b _NeverReturn
153