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Diffstat (limited to 'EDK/Foundation/Library/Pei/PeiLib/Ipf/SwitchStack.s')
| -rw-r--r-- | EDK/Foundation/Library/Pei/PeiLib/Ipf/SwitchStack.s | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/EDK/Foundation/Library/Pei/PeiLib/Ipf/SwitchStack.s b/EDK/Foundation/Library/Pei/PeiLib/Ipf/SwitchStack.s new file mode 100644 index 0000000..5de7e18 --- /dev/null +++ b/EDK/Foundation/Library/Pei/PeiLib/Ipf/SwitchStack.s @@ -0,0 +1,122 @@ +//++ +// Copyright (c) 2004, Intel Corporation +// 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. +// +// Module Name: +// +// SwitchStack.s +// +// Abstract: +// +// Contains an implementation of a stack switch for the Itanium-based architecture. +// +// +// +// Revision History: +// +//-- + + .file "SwitchStack.s" + +#include <asm.h> +#include <ia_64gen.h> + +// Define hardware RSE Configuration Register +// +// RS Configuration (RSC) bit field positions + +#define RSC_MODE 0 +#define RSC_PL 2 +#define RSC_BE 4 +// RSC bits 5-15 reserved +#define RSC_MBZ0 5 +#define RSC_MBZ0_V 0x3ff +#define RSC_LOADRS 16 +#define RSC_LOADRS_LEN 14 +// RSC bits 30-63 reserved +#define RSC_MBZ1 30 +#define RSC_MBZ1_V 0x3ffffffffULL + +// RSC modes +// Lazy +#define RSC_MODE_LY (0x0) +// Store intensive +#define RSC_MODE_SI (0x1) +// Load intensive +#define RSC_MODE_LI (0x2) +// Eager +#define RSC_MODE_EA (0x3) + +// RSC Endian bit values +#define RSC_BE_LITTLE 0 +#define RSC_BE_BIG 1 + +// RSC while in kernel: enabled, little endian, pl = 0, eager mode +#define RSC_KERNEL ((RSC_MODE_EA<<RSC_MODE) | (RSC_BE_LITTLE<<RSC_BE)) +// Lazy RSC in kernel: enabled, little endian, pl = 0, lazy mode +#define RSC_KERNEL_LAZ ((RSC_MODE_LY<<RSC_MODE) | (RSC_BE_LITTLE<<RSC_BE)) +// RSE disabled: disabled, pl = 0, little endian, eager mode +#define RSC_KERNEL_DISABLED ((RSC_MODE_LY<<RSC_MODE) | (RSC_BE_LITTLE<<RSC_BE)) + + +//VOID +//SwitchStacks ( +// VOID *ContinuationFunction, +// UINTN Parameter, +// UINTN NewTopOfStack, +// UINTN NewBSPStore OPTIONAL +//) +///*++ +// +//Input Arguments +// +// ContinuationFunction - This is a pointer to the PLABEL of the function that should be called once the +// new stack has been created. +// Parameter - The parameter to pass to the continuation function +// NewTopOfStack - This is the new top of the memory stack for ensuing code. This is mandatory and +// should be non-zero +// NewBSPStore - This is the new BSP store for the ensuing code. It is optional on IA-32 and mandatory on Itanium-based platform. +// +//--*/ + +PROCEDURE_ENTRY(SwitchStacks) + + mov r16 = -0x10;; + and r16 = r34, r16;; // get new stack value in R16, 0 the last nibble. + mov r15 = r35;; // Get new BspStore into R15 + mov r13 = r32;; // this is a pointer to the PLABEL of the continuation function. + mov r17 = r33;; // this is the parameter to pass to the continuation function + + alloc r11=0,0,0,0 // Set 0-size frame + ;; + flushrs;; + + mov r21 = RSC_KERNEL_DISABLED // for rse disable + ;; + mov ar.rsc = r21 // turn off RSE + + add sp = r0, r16;; // transfer to the EFI stack + mov ar.bspstore = r15 // switch to EFI BSP + invala // change of ar.bspstore needs invala. + + mov r18 = RSC_KERNEL_LAZ // RSC enabled, Lazy mode + ;; + mov ar.rsc = r18 // turn rse on, in kernel mode + ;; + alloc r11=0,0,1,0;; // alloc 0 outs going to ensuing DXE IPL service + mov out0 = r17 + ld8 r16 = [r13],8;; // r16 = address of continuation function from the PLABEL + ld8 gp = [r13] // gp = gp of continuation function from the PLABEL + mov b6 = r16 + ;; + br.call.sptk.few b0=b6;; // Call the continuation function + ;; +PROCEDURE_EXIT(SwitchStacks) + + |