diff options
Diffstat (limited to 'ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S')
| -rw-r--r-- | ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S b/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S new file mode 100644 index 0000000000..c0c20a9206 --- /dev/null +++ b/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S @@ -0,0 +1,149 @@ +//
+// Copyright (c) 2011-2013, ARM Limited. All rights reserved.
+//
+// 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 <AutoGen.h>
+
+#include <Chipset/ArmV7.h>
+
+.text
+.align 3
+
+GCC_ASM_IMPORT(CEntryPoint)
+GCC_ASM_IMPORT(ArmReadMpidr)
+GCC_ASM_IMPORT(ArmPlatformStackSet)
+GCC_ASM_EXPORT(_ModuleEntryPoint)
+
+StartupAddr: .word CEntryPoint
+
+
+ASM_PFX(_ModuleEntryPoint):
+ // Get ID of this CPU in Multicore system
+ bl ASM_PFX(ArmReadMpidr)
+ LoadConstantToReg (FixedPcdGet32(PcdArmPrimaryCoreMask), r1)
+ and r6, r0, r1
+
+_SetSVCMode:
+ // Enter SVC mode, Disable FIQ and IRQ
+ mov r1, #(CPSR_MODE_SVC | CPSR_IRQ | CPSR_FIQ)
+ msr CPSR_c, r1
+
+// Check if we can install the stack at the top of the System Memory or if we need
+// to install the stacks at the bottom of the Firmware Device (case the FD is located
+// at the top of the DRAM)
+_SetupStackPosition:
+ // Compute Top of System Memory
+ LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryBase), r1)
+ LoadConstantToReg (FixedPcdGet32(PcdSystemMemorySize), r2)
+ sub r2, r2, #1
+ add r1, r1, r2 // r1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize
+
+ // Calculate Top of the Firmware Device
+ LoadConstantToReg (FixedPcdGet32(PcdFdBaseAddress), r2)
+ LoadConstantToReg (FixedPcdGet32(PcdFdSize), r3)
+ sub r3, r3, #1
+ add r3, r3, r2 // r3 = FdTop = PcdFdBaseAddress + PcdFdSize
+
+ // UEFI Memory Size (stacks are allocated in this region)
+ LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryUefiRegionSize), r4)
+
+ //
+ // Reserve the memory for the UEFI region (contain stacks on its top)
+ //
+
+ // Calculate how much space there is between the top of the Firmware and the Top of the System Memory
+ subs r0, r1, r3 // r0 = SystemMemoryTop - FdTop
+ bmi _SetupStack // Jump if negative (FdTop > SystemMemoryTop). Case when the PrePi is in XIP memory outside of the DRAM
+ cmp r0, r4
+ bge _SetupStack
+
+ // Case the top of stacks is the FdBaseAddress
+ mov r1, r2
+
+_SetupStack:
+ // r1 contains the top of the stack (and the UEFI Memory)
+
+ // Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment
+ // one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the
+ // top of the memory space)
+ adds r7, r1, #1
+ bcs _SetupOverflowStack
+
+_SetupAlignedStack:
+ mov r1, r7
+ b _GetBaseUefiMemory
+
+_SetupOverflowStack:
+ // Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE
+ // aligned (4KB)
+ LoadConstantToReg (EFI_PAGE_MASK, r7)
+ and r7, r7, r1
+ sub r1, r1, r7
+
+_GetBaseUefiMemory:
+ // Calculate the Base of the UEFI Memory
+ sub r7, r1, r4
+
+_GetStackBase:
+ // r1 = The top of the Mpcore Stacks
+ // Stack for the primary core = PrimaryCoreStack
+ LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)
+ sub r8, r1, r2
+
+ // Stack for the secondary core = Number of Cores - 1
+ LoadConstantToReg (FixedPcdGet32(PcdCoreCount), r0)
+ sub r0, r0, #1
+ LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r1)
+ mul r1, r1, r0
+ sub r8, r8, r1
+
+ // r8 = The base of the MpCore Stacks (primary stack & secondary stacks)
+ mov r0, r8
+ mov r1, r6
+ //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
+ LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)
+ LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r3)
+ bl ASM_PFX(ArmPlatformStackSet)
+
+ // Is it the Primary Core ?
+ LoadConstantToReg (FixedPcdGet32(PcdArmPrimaryCore), r4)
+ cmp r6, r4
+ bne _PrepareArguments
+
+_ReserveGlobalVariable:
+ LoadConstantToReg (FixedPcdGet32(PcdPeiGlobalVariableSize), r0)
+ // InitializePrimaryStack($GlobalVariableSize, $Tmp1)
+ InitializePrimaryStack(r0, r1)
+
+_PrepareArguments:
+ mov r0, r6
+ mov r1, r7
+ mov r2, r8
+ mov r3, sp
+
+ // Move sec startup address into a data register
+ // Ensure we're jumping to FV version of the code (not boot remapped alias)
+ ldr r4, StartupAddr
+
+ // Jump to PrePiCore C code
+ // r0 = MpId
+ // r1 = UefiMemoryBase
+ // r2 = StacksBase
+ // r3 = GlobalVariableBase
+ blx r4
+
+_NeverReturn:
+ b _NeverReturn
+
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