soc/intel/pantherlake: Implement UX help APIs for eSOL handling

This patch refactors the eSOL implementation for Panther Lake and
introduces two new APIs, mirroring those in Alder Lake, to manage:

- Low battery shutdown notifications
- Firmware update memory training

BUG=b:397302064
TEST=Built and booted google/fatcat successfully.

Change-Id: I14229af4a4920414f3c572576d67fa6d665681cd
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/86509
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>
Reviewed-by: Jayvik Desai <jayvik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/pantherlake/romstage/Makefile.mk

@@ -4,3 +4,4 @@ romstage-y += fsp_params.c
 romstage-y += ../../../../cpu/intel/car/romstage.c
 romstage-y += romstage.c
 romstage-y += systemagent.c
+romstage-y += ux.c

src/soc/intel/pantherlake/romstage/ux.c

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <bootmode.h>
+#include <console/console.h>
+#include <fsp/util.h>
+#include <timestamp.h>
+#include <ux_locales.h>
+
+#include "ux.h"
+
+static bool ux_inform_user_of_operation(const char *name, enum ux_locale_msg id,
+		 FSPM_UPD *mupd)
+{
+	timestamp_add_now(TS_ESOL_START);
+
+	if (!CONFIG(CHROMEOS_ENABLE_ESOL)) {
+		timestamp_add_now(TS_ESOL_END);
+		return false;
+	}
+
+	FSP_M_CONFIG *m_cfg = &mupd->FspmConfig;
+	void *vbt;
+	size_t vbt_size;
+	static bool ux_done = false;
+
+	/*
+	 * Prevents multiple VGA text messages from being rendered during the boot process.
+	 *
+	 * This function is designed to be called only once. Subsequent calls are intentionally
+	 * ignored to avoid overwriting previously displayed messages. For example, if a
+	 * low-battery shutdown notification is scheduled, a later call with a firmware
+	 * update notification could result in the low-battery message being lost.
+	 */
+	if (ux_done) {
+		timestamp_add_now(TS_ESOL_END);
+		return true;
+	}
+
+	printk(BIOS_INFO, "Informing user on-display of %s.\n", name);
+
+	vbt = cbfs_map("vbt.bin", &vbt_size);
+	if (!vbt) {
+		printk(BIOS_ERR, "Could not load vbt.bin\n");
+		return false;
+	}
+
+	m_cfg->VgaInitControl = 1;
+	m_cfg->VbtPtr = (efi_uintn_t)vbt;
+	m_cfg->VbtSize = vbt_size;
+	m_cfg->LidStatus = CONFIG(VBOOT_LID_SWITCH) ? get_lid_switch() : CONFIG(RUN_FSP_GOP);
+	m_cfg->VgaMessage = (efi_uintn_t)ux_locales_get_text(id);
+
+	ux_done = true;
+
+	timestamp_add_now(TS_ESOL_END);
+	return true;
+}
+
+bool ux_inform_user_of_update_operation(const char *name, FSPM_UPD *mupd)
+{
+	return ux_inform_user_of_operation(name, UX_LOCALE_MSG_MEMORY_TRAINING, mupd);
+}
+
+bool ux_inform_user_of_poweroff_operation(const char *name, FSPM_UPD *mupd)
+{
+	return ux_inform_user_of_operation(name, UX_LOCALE_MSG_LOW_BATTERY, mupd);
+}

src/soc/intel/pantherlake/romstage/ux.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _SOC_INTEL_PANTHERLAKE_ROMSTAGE_UX_H_
+#define _SOC_INTEL_PANTHERLAKE_ROMSTAGE_UX_H_
+
+bool ux_inform_user_of_update_operation(const char *name, FSPM_UPD *mupd);
+bool ux_inform_user_of_poweroff_operation(const char *name, FSPM_UPD *mupd);
+
+#endif /* _SOC_INTEL_PANTHERLAKE_ROMSTAGE_UX_H_ */