nb/intel/haswell: Introduce option to not use MRC.bin

Introduce the `USE_NATIVE_RAMINIT` Kconfig option, which should allow
booting coreboot on Haswell mainboards without the need of the closed
source MRC.bin. For now, this option does not work at all; the needed
magic will be implemented in subsequent commits. Add a config file to
make sure the newly-introduced option gets build-tested.

Change-Id: I46c77586f9b5771624082e07c60c205e578edd8e
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64176
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

configs/config.asrock_b85m_pro4.native_raminit

@@ -0,0 +1,5 @@
+# Configuration used to build-test native raminit
+CONFIG_VENDOR_ASROCK=y
+CONFIG_BOARD_ASROCK_B85M_PRO4=y
+CONFIG_USE_NATIVE_RAMINIT=y
+CONFIG_DEBUG_RAM_SETUP=y

src/northbridge/intel/haswell/Kconfig

@@ -9,6 +9,14 @@ config NORTHBRIDGE_INTEL_HASWELL
 
 if NORTHBRIDGE_INTEL_HASWELL
 
+config USE_NATIVE_RAMINIT
+	bool "[NOT WORKING] Use native raminit"
+	default n
+	select HAVE_DEBUG_RAM_SETUP
+	help
+	  Select if you want to use coreboot implementation of raminit rather than
+	  MRC.bin. Currently incomplete and does not boot.
+
 config HASWELL_VBOOT_IN_BOOTBLOCK
 	depends on VBOOT
 	bool "Start verstage in bootblock"
@@ -45,6 +53,7 @@ config DCACHE_RAM_BASE
 
 config DCACHE_RAM_SIZE
 	hex
+	default 0x40000 if USE_NATIVE_RAMINIT
 	default 0x10000
 	help
 	  The size of the cache-as-ram region required during bootblock
@@ -53,12 +62,14 @@ config DCACHE_RAM_SIZE
 
 config DCACHE_RAM_MRC_VAR_SIZE
 	hex
+	default 0x0 if USE_NATIVE_RAMINIT
 	default 0x30000
 	help
 	  The amount of cache-as-ram region required by the reference code.
 
 config DCACHE_BSP_STACK_SIZE
 	hex
+	default 0x20000 if USE_NATIVE_RAMINIT
 	default 0x2000
 	help
 	  The amount of anticipated stack usage in CAR by bootblock and
@@ -66,6 +77,7 @@ config DCACHE_BSP_STACK_SIZE
 
 config HAVE_MRC
 	bool "Add a System Agent binary"
+	depends on !USE_NATIVE_RAMINIT
 	help
 	  Select this option to add a System Agent binary to
 	  the resulting coreboot image.
@@ -82,6 +94,7 @@ config MRC_FILE
 
 config HASWELL_HIDE_PEG_FROM_MRC
 	bool "Hide PEG devices from MRC to work around hardcoded MRC behavior"
+	depends on !USE_NATIVE_RAMINIT
 	default y
 	help
 	  If set, hides all PEG devices from MRC. This allows the iGPU

src/northbridge/intel/haswell/Makefile.inc

@@ -19,6 +19,11 @@ romstage-y += report_platform.c
 
 postcar-y += memmap.c
 
-subdirs-y += haswell_mrc
+ifeq ($(CONFIG_USE_NATIVE_RAMINIT),y)
+subdirs-y  += native_raminit
+
+else
+subdirs-y  += haswell_mrc
+endif
 
 endif

src/northbridge/intel/haswell/native_raminit/Makefile.inc

@@ -0,0 +1,3 @@
+## SPDX-License-Identifier: GPL-2.0-or-later
+
+romstage-y += raminit_native.c

src/northbridge/intel/haswell/native_raminit/raminit_native.c

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <console/console.h>
+#include <northbridge/intel/haswell/raminit.h>
+
+void perform_raminit(const int s3resume)
+{
+	/*
+	 * See, this function's name is a lie. There are more things to
+	 * do that memory initialisation, but they are relatively easy.
+	 */
+
+	/** TODO: Implement the required magic **/
+	die("NATIVE RAMINIT: More Magic (tm) required.\n");
+}