From a8bce33b82c3d4b40d0177169224f70229528c5b Mon Sep 17 00:00:00 2001
From: Kilian Krause <kilian.krause@siemens.com>
Date: Thu, 10 Jul 2025 15:24:30 +0200
Subject: [PATCH] mb/siemens/mc_rpl: Disable Intel Turbo Boost

Disable Intel Turbo Boost on this platform as a first step toward
consistent frequency behavior. This platform requires deterministic
performance characteristics rather than dynamic frequency scaling.

TEST=Boot into OS, read MSR 0x1A0 (IA32_MISC_ENABLE) and verify that bit
38 (Turbo Disable) is set.

Change-Id: I6e89cdaaa56b5e5c70461ac67159c0fc3975a429
Signed-off-by: Kilian Krause <kilian.krause@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88959
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
---
 src/mainboard/siemens/mc_rpl/mainboard.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/mainboard/siemens/mc_rpl/mainboard.c b/src/mainboard/siemens/mc_rpl/mainboard.c
index fe3e1e6216..e5c399f269 100644
--- a/src/mainboard/siemens/mc_rpl/mainboard.c
+++ b/src/mainboard/siemens/mc_rpl/mainboard.c
@@ -8,6 +8,7 @@
 #include <stdio.h>
 #include <hwilib.h>
 #include <i210.h>
+#include <soc/ramstage.h>
 
 
 #define MAX_PATH_DEPTH		12
@@ -86,6 +87,11 @@ enum cb_err mainboard_get_mac_address(struct device *dev, uint8_t mac[MAC_ADDR_L
 	return CB_ERR;
 }
 
+void mainboard_silicon_init_params(FSP_S_CONFIG *params)
+{
+	params->TurboMode = 0;
+}
+
 static void mainboard_init(void *chip_info)
 {
 	variant_configure_gpio_pads();