system76-edk2/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm
Ard Biesheuvel 7e2a8dfe8a ArmPlatformPkg/PrePeiCore: seed temporary stack before entering PEI core
DEBUG builds of PEI code will print a diagnostic message regarding
the utilization of temporary RAM before switching to permanent RAM.
For example,

  Total temporary memory:    16352 bytes.
    temporary memory stack ever used:       4820 bytes.
    temporary memory heap used for HobList: 4720 bytes.

Tracking stack utilization like this requires the stack to be seeded
with a known magic value, and this needs to occur before entering C
code, given that it uses the stack. Currently, only Nt32Pkg appears
to implement this feature, but it is useful nonetheless, so let's
wire it up for PrePeiCore.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
2017-11-09 21:08:07 +00:00

96 lines
2.7 KiB
NASM

//
// 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 <AutoGen.h>
INCLUDE AsmMacroIoLib.inc
IMPORT CEntryPoint
IMPORT ArmPlatformGetCorePosition
IMPORT ArmPlatformIsPrimaryCore
IMPORT ArmReadMpidr
IMPORT ArmPlatformPeiBootAction
EXPORT _ModuleEntryPoint
PRESERVE8
AREA PrePeiCoreEntryPoint, CODE, READONLY
StartupAddr DCD CEntryPoint
_ModuleEntryPoint
// Do early platform specific actions
bl ArmPlatformPeiBootAction
// Identify CPU ID
bl ArmReadMpidr
// Keep a copy of the MpId register value
mov r5, r0
// Is it the Primary Core ?
bl ArmPlatformIsPrimaryCore
// Get the top of the primary stacks (and the base of the secondary stacks)
mov32 r1, FixedPcdGet64(PcdCPUCoresStackBase) + FixedPcdGet32(PcdCPUCorePrimaryStackSize)
// r0 is equal to 1 if I am the primary core
cmp r0, #1
beq _SetupPrimaryCoreStack
_SetupSecondaryCoreStack
// r1 contains the base of the secondary stacks
// Get the Core Position
mov r6, r1 // Save base of the secondary stacks
mov r0, r5
bl ArmPlatformGetCorePosition
// The stack starts at the top of the stack region. Add '1' to the Core Position to get the top of the stack
add r0, r0, #1
// StackOffset = CorePos * StackSize
mov32 r2, FixedPcdGet32(PcdCPUCoreSecondaryStackSize)
mul r0, r0, r2
// SP = StackBase + StackOffset
add sp, r6, r0
_PrepareArguments
// The PEI Core Entry Point has been computed by GenFV and stored in the second entry of the Reset Vector
mov32 r2, FixedPcdGet32(PcdFvBaseAddress)
ldr r1, [r2, #4]
// Move sec startup address into a data register
// Ensure we're jumping to FV version of the code (not boot remapped alias)
ldr r3, StartupAddr
// Jump to PrePeiCore C code
// r0 = mp_id
// r1 = pei_core_address
mov r0, r5
blx r3
_SetupPrimaryCoreStack
mov sp, r1
mov32 r8, FixedPcdGet64 (PcdCPUCoresStackBase)
mov32 r9, FixedPcdGet32 (PcdInitValueInTempStack)
mov r10, r9
mov r11, r9
mov r12, r9
0:stm r8!, {r9-r12}
cmp r8, r1
blt 0b
b _PrepareArguments
_NeverReturn
b _NeverReturn
END