4 files changed, 351 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/cse/Kconfig b/src/soc/intel/common/block/cse/Kconfig
index 15de0b0536..e566dddcce 100644
--- a/src/soc/intel/common/block/cse/Kconfig
+++ b/src/soc/intel/common/block/cse/Kconfig
@@ -12,3 +12,10 @@ config SOC_INTEL_COMMON_BLOCK_HECI_DISABLE_IN_SMM
 	help
 	  Use this config to include common CSE block to make HECI function
 	  disable in SMM mode
+
+config SOC_INTEL_CSE_CUSTOM_SKU
+	bool
+	default n
+	depends on CHROMEOS
+	help
+	 Enables CSE Custom SKU
diff --git a/src/soc/intel/common/block/cse/Makefile.inc b/src/soc/intel/common/block/cse/Makefile.inc
index 90f76d59b0..418b7a2efa 100644
--- a/src/soc/intel/common/block/cse/Makefile.inc
+++ b/src/soc/intel/common/block/cse/Makefile.inc
@@ -1,4 +1,5 @@
 bootblock-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CSE) += cse.c
 romstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CSE) += cse.c
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CSE) += cse.c
+ramstage-$(CONFIG_SOC_INTEL_CSE_CUSTOM_SKU) += custom_bp.c
 smm-$(CONFIG_SOC_INTEL_COMMON_BLOCK_HECI_DISABLE_IN_SMM) += disable_heci.c
diff --git a/src/soc/intel/common/block/cse/custom_bp.c b/src/soc/intel/common/block/cse/custom_bp.c
new file mode 100644
index 0000000000..653684a7bd
--- /dev/null
+++ b/src/soc/intel/common/block/cse/custom_bp.c
@@ -0,0 +1,329 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
+#include <bootstate.h>
+#include <console/console.h>
+#include <soc/intel/common/reset.h>
+#include <intelblocks/cse.h>
+#include <security/vboot/vboot_common.h>
+#include <string.h>
+
+/* Converts bp index to boot partition string */
+#define GET_BP_STR(bp_index) (bp_index ? "RW" : "RO")
+
+/*
+ * CSE Firmware supports 3 boot partitions. For CSE Custom SKU, only 2 boot partitions are
+ * used and 3rd boot partition is set to BP_STATUS_PARTITION_NOT_PRESENT.
+ * CSE Custom SKU Image Layout:
+ * -------------    -------------------    ---------------------
+ * |CSE REGION | => | RO |  RW | DATA | => | BP1 | BP2  | DATA |
+ *  -------------   -------------------    ---------------------
+ */
+#define CSE_MAX_BOOT_PARTITIONS 3
+
+/* CSE Custom SKU's valid bootable partition identifiers */
+enum boot_partition_id {
+	/* RO(BP1) contains recovery/minimal boot FW */
+	RO = 0,
+
+	/* RW(BP2) contains fully functional CSE Firmware */
+	RW = 1
+};
+
+/*
+ * Boot partition status.
+ * The status is returned in response to MKHI_BUP_COMMON_GET_BOOT_PARTITION_INFO cmd.
+ */
+enum bp_status {
+	/* This value is returned when a partition has no errors */
+	BP_STATUS_SUCCESS = 0,
+
+	/*
+	 * This value is returned when a partition should be present based on layout, but it is
+	 * not valid.
+	 */
+	BP_STATUS_GENERAL_FAILURE = 1,
+
+	/* This value is returned when a partition is not present per initial image layout */
+	BP_STATUS_PARTITION_NOT_PRESENT = 2,
+
+};
+
+/*
+ * Boot Partition Info Flags
+ * The flags are returned in response to MKHI_BUP_COMMON_GET_BOOT_PARTITION_INFO cmd.
+ */
+enum bp_info_flags {
+
+	/* Redundancy Enabled: It indicates CSE supports RO(BP1) and RW(BP2) regions */
+	BP_INFO_REDUNDANCY_EN = 1 << 0,
+
+	/* It indicates RO(BP1) supports Minimal Recovery Mode */
+	BP_INFO_MIN_RECOV_MODE_EN = 1 << 1,
+
+	/*
+	 * Read-only Config Enabled: It indicates HW protection to CSE RO region is enabled.
+	 * The option is relevant only if the BP_INFO_MIN_RECOV_MODE_EN flag is enabled.
+	 */
+	BP_INFO_READ_ONLY_CFG = 1 << 2,
+};
+
+/* Boot Partition FW Version */
+struct fw_version {
+	uint16_t major;
+	uint16_t minor;
+	uint16_t hotfix;
+	uint16_t build;
+} __packed;
+
+/* CSE boot partition entry info */
+struct cse_bp_entry {
+	/* Boot partition version */
+	struct fw_version fw_ver;
+
+	/* Boot partition status */
+	uint32_t status;
+
+	/* Starting offset of the partition within CSE region */
+	uint32_t start_offset;
+
+	/* Ending offset of the partition within CSE region */
+	uint32_t end_offset;
+	uint8_t reserved[12];
+} __packed;
+
+/* CSE boot partition info */
+struct cse_bp_info {
+	/* Number of boot partitions */
+	uint8_t total_number_of_bp;
+
+	/* Current boot partition */
+	uint8_t current_bp;
+
+	/* Next boot partition */
+	uint8_t next_bp;
+
+	/* Boot Partition Info Flags */
+	uint8_t flags;
+
+	/* Boot Partition Entry Info */
+	struct cse_bp_entry bp_entries[CSE_MAX_BOOT_PARTITIONS];
+} __packed;
+
+struct get_bp_info_rsp {
+	struct mkhi_hdr hdr;
+	struct cse_bp_info bp_info;
+} __packed;
+
+static uint8_t cse_get_current_bp(const struct cse_bp_info *cse_bp_info)
+{
+	return cse_bp_info->current_bp;
+}
+
+static const struct cse_bp_entry *cse_get_bp_entry(enum boot_partition_id bp,
+		const struct cse_bp_info *cse_bp_info)
+{
+	return &cse_bp_info->bp_entries[bp];
+}
+
+static void cse_print_boot_partition_info(const struct cse_bp_info *cse_bp_info)
+{
+	const struct cse_bp_entry *cse_bp;
+
+	printk(BIOS_DEBUG, "ME: Number of partitions = %d\n", cse_bp_info->total_number_of_bp);
+	printk(BIOS_DEBUG, "ME: Current partition = %s\n", GET_BP_STR(cse_bp_info->current_bp));
+	printk(BIOS_DEBUG, "ME: Next partition = %s\n", GET_BP_STR(cse_bp_info->next_bp));
+	printk(BIOS_DEBUG, "ME: Flags = 0x%x\n", cse_bp_info->flags);
+
+	/* Log version info of RO & RW partitions */
+	cse_bp = cse_get_bp_entry(RO, cse_bp_info);
+	printk(BIOS_DEBUG, "ME: %s version = %d.%d.%d.%d (Status=0x%x, Start=0x%x, End=0x%x)\n",
+			GET_BP_STR(RO), cse_bp->fw_ver.major, cse_bp->fw_ver.minor,
+			cse_bp->fw_ver.hotfix, cse_bp->fw_ver.build,
+			cse_bp->status, cse_bp->start_offset,
+			cse_bp->end_offset);
+
+	cse_bp = cse_get_bp_entry(RW, cse_bp_info);
+	printk(BIOS_DEBUG, "ME: %s version = %d.%d.%d.%d (Status=0x%x, Start=0x%x, End=0x%x)\n",
+			GET_BP_STR(RW), cse_bp->fw_ver.major, cse_bp->fw_ver.minor,
+			cse_bp->fw_ver.hotfix, cse_bp->fw_ver.build,
+			cse_bp->status, cse_bp->start_offset,
+			cse_bp->end_offset);
+}
+
+/*
+ * Checks prerequisites for MKHI_BUP_COMMON_GET_BOOT_PARTITION_INFO and
+ * MKHI_BUP_COMMON_SET_BOOT_PARTITION_INFO HECI commands.
+ * It allows execution of the Boot Partition commands in below scenarios:
+ *	- When CSE boots from RW partition (COM: Normal and CWS: Normal)
+ *	- When CSE boots from RO partition (COM: Soft Temp Disable and CWS: Normal)
+ *	- After HMRFPO_ENABLE command is issued to CSE (COM: SECOVER_MEI_MSG and CWS: Normal)
+ */
+static bool cse_is_bp_cmd_info_possible(void)
+{
+	if (cse_is_hfs1_cws_normal()) {
+		if (cse_is_hfs1_com_normal())
+			return true;
+		if (cse_is_hfs1_com_secover_mei_msg())
+			return true;
+		if (cse_is_hfs1_com_soft_temp_disable())
+			return true;
+	}
+	return false;
+}
+
+static bool cse_get_bp_info(struct get_bp_info_rsp *bp_info_rsp)
+{
+	struct get_bp_info_req {
+		struct mkhi_hdr hdr;
+		uint8_t reserved[4];
+	} __packed;
+
+	struct get_bp_info_req info_req = {
+		.hdr.group_id = MKHI_GROUP_ID_BUP_COMMON,
+		.hdr.command = MKHI_BUP_COMMON_GET_BOOT_PARTITION_INFO,
+		.reserved = {0},
+	};
+
+	if (!cse_is_bp_cmd_info_possible()) {
+		printk(BIOS_ERR, "cse_bp: CSE does not meet prerequisites\n");
+		return false;
+	}
+
+	size_t resp_size = sizeof(struct get_bp_info_rsp);
+
+	if (!heci_send_receive(&info_req, sizeof(info_req), bp_info_rsp, &resp_size)) {
+		printk(BIOS_ERR, "cse_bp: Could not get partition info\n");
+		return false;
+	}
+
+	if (bp_info_rsp->hdr.result) {
+		printk(BIOS_ERR, "cse_bp: Get partition info resp failed: %d\n",
+				bp_info_rsp->hdr.result);
+		return false;
+	}
+
+	cse_print_boot_partition_info(&bp_info_rsp->bp_info);
+
+	return true;
+}
+/*
+ * It sends HECI command to notify CSE about its next boot partition. When coreboot wants
+ * CSE to boot from certain partition (BP1 <RO> or BP2 <RW>), then this command can be used.
+ * The CSE's valid bootable partitions are BP1(RO) and BP2(RW).
+ * This function must be used before EOP.
+ * Returns false on failure and true on success.
+ */
+static bool cse_set_next_boot_partition(enum boot_partition_id bp)
+{
+	struct set_boot_partition_info_req {
+		struct mkhi_hdr hdr;
+		uint8_t next_bp;
+		uint8_t reserved[3];
+	} __packed;
+
+	struct set_boot_partition_info_req switch_req = {
+		.hdr.group_id = MKHI_GROUP_ID_BUP_COMMON,
+		.hdr.command = MKHI_BUP_COMMON_SET_BOOT_PARTITION_INFO,
+		.next_bp = bp,
+		.reserved = {0},
+	};
+
+	if (bp != RO && bp != RW) {
+		printk(BIOS_ERR, "cse_bp: Incorrect partition id(%d) is provided", bp);
+		return false;
+	}
+
+	printk(BIOS_INFO, "cse_bp: Set Boot Partition Info Command (%s)\n", GET_BP_STR(bp));
+
+	if (!cse_is_bp_cmd_info_possible()) {
+		printk(BIOS_ERR, "cse_bp: CSE does not meet prerequisites\n");
+		return false;
+	}
+
+	struct mkhi_hdr switch_resp;
+	size_t sw_resp_sz = sizeof(struct mkhi_hdr);
+
+	if (!heci_send_receive(&switch_req, sizeof(switch_req), &switch_resp, &sw_resp_sz))
+		return false;
+
+	if (switch_resp.result) {
+		printk(BIOS_ERR, "cse_bp: Set Boot Partition Info Response Failed: %d\n",
+				switch_resp.result);
+		return false;
+	}
+
+	return true;
+}
+
+static bool cse_boot_to_rw(const struct cse_bp_info *cse_bp_info)
+{
+	if (cse_get_current_bp(cse_bp_info) == RW)
+		return true;
+
+	if (!cse_set_next_boot_partition(RW))
+		return false;
+
+	do_global_reset();
+
+	die("cse_bp: Failed to reset system\n");
+
+	/* Control never reaches here */
+	return false;
+}
+
+static bool cse_is_rw_status_valid(const struct cse_bp_info *cse_bp_info)
+{
+	const struct cse_bp_entry *rw_bp;
+
+	/* RW(BP2) alone represents RW partition */
+	rw_bp = cse_get_bp_entry(RW, cse_bp_info);
+
+	if (rw_bp->status == BP_STATUS_PARTITION_NOT_PRESENT ||
+			rw_bp->status == BP_STATUS_GENERAL_FAILURE) {
+		printk(BIOS_ERR, "cse_bp: RW BP (status:%u) is not valid\n", rw_bp->status);
+		return false;
+	}
+	return true;
+}
+
+static bool cse_is_rw_info_valid(struct cse_bp_info *cse_bp_info)
+{
+	return cse_is_rw_status_valid(cse_bp_info);
+}
+
+void cse_fw_sync(void *unused)
+{
+	static struct get_bp_info_rsp cse_bp_info;
+
+	if (vboot_recovery_mode_enabled()) {
+		printk(BIOS_DEBUG, "cse_bp: Skip switching to RW in the recovery path\n");
+		return;
+	}
+
+	/* If CSE SKU type is not Custom, skip enabling CSE Custom SKU */
+	if (!cse_is_hfs3_fw_sku_custom()) {
+		printk(BIOS_ERR, "cse_bp: Not a CSE Custom SKU\n");
+		return;
+	}
+
+	if (!cse_get_bp_info(&cse_bp_info)) {
+		printk(BIOS_ERR, "cse_bp: Failed to get CSE boot partition info\n");
+		goto failed;
+	}
+
+
+	if (!cse_is_rw_info_valid(&cse_bp_info.bp_info)) {
+		printk(BIOS_ERR, "cse_bp: CSE RW partition is not valid\n");
+		goto failed;
+	}
+
+	if (!cse_boot_to_rw(&cse_bp_info.bp_info)) {
+		printk(BIOS_ERR, "cse_bp: Failed to switch to RW\n");
+		goto failed;
+	}
+	return;
+failed:
+	do_global_reset();
+}
+
+BOOT_STATE_INIT_ENTRY(BS_PRE_DEVICE, BS_ON_ENTRY, cse_fw_sync, NULL);
diff --git a/src/soc/intel/common/block/include/intelblocks/cse.h b/src/soc/intel/common/block/include/intelblocks/cse.h
index ead5d41e8c..5cad63c47f 100644
--- a/src/soc/intel/common/block/include/intelblocks/cse.h
+++ b/src/soc/intel/common/block/include/intelblocks/cse.h
@@ -23,6 +23,7 @@
 #define MKHI_GROUP_ID_CBM	0x0
 #define MKHI_GROUP_ID_HMRFPO	0x5
 #define MKHI_GROUP_ID_GEN	0xff
+#define MKHI_GROUP_ID_BUP_COMMON	0xf0
 
 /* Global Reset Command ID */
 #define MKHI_CBM_GLOBAL_RESET_REQ	0xb
@@ -37,6 +38,10 @@
 /* Get Firmware Version Command Id */
 #define MKHI_GEN_GET_FW_VERSION	0x2
 
+/* Boot partition info and set boot partition info command ids */
+#define MKHI_BUP_COMMON_GET_BOOT_PARTITION_INFO	0x1c
+#define MKHI_BUP_COMMON_SET_BOOT_PARTITION_INFO	0x1d
+
 /* ME Current Working States */
 #define ME_HFS1_CWS_NORMAL	0x5
 
@@ -219,4 +224,13 @@ bool cse_is_hfs3_fw_sku_custom(void);
  * Returns 0 on failure and 1 on success.
  */
 uint8_t cse_wait_com_soft_temp_disable(void);
+
+/*
+ * The CSE Custom SKU supports notion of RO and RW boot partitions. The function will set
+ * CSE's boot partition as per Chrome OS boot modes. In normal mode, the function allows CSE to
+ * boot from RW and triggers recovery mode if CSE fails to jump to RW.
+ * In software triggered recovery mode, the function allows CSE to boot from whatever is
+ * currently selected partition.
+ */
+void cse_fw_sync(void *unused);
 #endif // SOC_INTEL_COMMON_CSE_H