sections/cper-section-arm-ras.c

/**
 * See: https://developer.arm.com/documentation/den0085/latest/
 * Minimal parser/generator for ARM RAS CPER section (Table 20/21)
 * Author: prachotan.bathi@arm.com
 */
#include <libcper/Cper.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <inttypes.h>
#include <libcper/base64.h>
#include <libcper/cper-utils.h>
#include <libcper/sections/cper-section-arm-ras.h>
#include <libcper/log.h>

/*
 * Fixed-size fields in EFI_ARM_RAS_NODE.
 *
 * IPInstance: 16 bytes, serialized as a 32-character hex string.
 * IPType:     24 bytes, serialized as a 48-character hex string.
 * UserData:   16 bytes, but we emit up to 15 chars to keep a terminator.
 */
static void arm_ras_set_desc_string_valid(char **desc_string)
{
	if (desc_string) {
		*desc_string = malloc(SECTION_DESC_STRING_SIZE);
		if (*desc_string) {
			snprintf(*desc_string, SECTION_DESC_STRING_SIZE,
				 "ARM RAS error occured");
		}
	}
}

static void arm_ras_set_desc_string_invalid(const char *reason,
					    char **desc_string)
{
	if (desc_string) {
		*desc_string = malloc(SECTION_DESC_STRING_SIZE);
		if (*desc_string) {
			snprintf(*desc_string, SECTION_DESC_STRING_SIZE,
				 "ARM RAS (empty): %s",
				 reason ? reason : "unspecified");
		}
	}
}

static bool arm_ras_read_node(EFI_ARM_RAS_NODE *node, const UINT8 *section,
			      UINT32 size, char **desc_string,
			      json_object **root)
{
	char reason[SECTION_DESC_STRING_SIZE];
	*root = json_object_new_object();
	if (size < sizeof(EFI_ARM_RAS_NODE)) {
		cper_print_log("ARM RAS section too small: %u < %zu",
			       (unsigned)size, sizeof(EFI_ARM_RAS_NODE));
		snprintf(reason, sizeof(reason), "invalid/too small %u < %zu",
			 (unsigned)size, sizeof(EFI_ARM_RAS_NODE));
		arm_ras_set_desc_string_invalid(reason, desc_string);
		return false;
	}

	memcpy(node, section, sizeof(*node));
	UINT32 descriptorCount = node->ErrorSyndromeArrayNumEntries;
	UINT64 descBytes = (UINT64)descriptorCount *
			   (UINT64)sizeof(EFI_ARM_RAS_ERROR_RECORD_DESCRIPTOR);
	if (descBytes > (UINT64)(size - node->ErrorSyndromeArrayOffset)) {
		cper_print_log("ARM RAS descriptor array out of range");
		snprintf(reason, sizeof(reason),
			 "descriptor array out of range");
		arm_ras_set_desc_string_invalid(reason, desc_string);
		return false;
	}
	if (node->Revision != 1) {
		cper_print_log("Unsupported ARM RAS revision: %u",
			       node->Revision);
		snprintf(reason, sizeof(reason),
			 "unsupported ARM RAS revision: %u", node->Revision);
		arm_ras_set_desc_string_invalid(reason, desc_string);
		return false;
	}

	if (node->ErrorSyndromeArrayOffset < sizeof(EFI_ARM_RAS_NODE) ||
	    node->ErrorSyndromeArrayOffset >= size ||
	    (node->AuxiliaryDataOffset && node->AuxiliaryDataOffset >= size)) {
		cper_print_log("Invalid ARM RAS offsets");
		snprintf(reason, sizeof(reason), "invalid ARM RAS offsets");
		arm_ras_set_desc_string_invalid(reason, desc_string);
		return false;
	}

	return true;
}

static const char *ipInstanceFormat[] = { "PE", "SystemPhysicalAddress",
					  "LocalAddressIdentifier",
					  "SocSpecificIpIdentifier" };

static const char *componentType[] = {
	"ProcessorErrorNode",	  "MemoryErrorNode", "SMMUErrorNode",
	"VendorDefinedErrorNode", "GICErrorNode",    "PciExpressErrorNode",
	"ProxyErrorNode",
};

static void arm_ras_add_fixed_fields(json_object *root,
				     const EFI_ARM_RAS_NODE *node)
{
	add_uint(root, "revision", node->Revision);
	add_dict(root, "componentType", node->ComponentType, componentType,
		 sizeof(componentType) / sizeof(componentType[0]));
	add_uint(root, "errorSyndromeArrayNumEntries",
		 node->ErrorSyndromeArrayNumEntries);

	add_dict(root, "ipInstanceFormat", node->IPInstanceFormat,
		 ipInstanceFormat,
		 sizeof(ipInstanceFormat) / sizeof(ipInstanceFormat[0]));

	json_object *ipInstance = json_object_new_object();
	switch (node->IPInstanceFormat) {
	case 0:
		add_int_hex_64(ipInstance, "mpidrEl1",
			       node->IPInstance.pe.MPIDR_EL1);
		break;
	case 1:
		add_int_hex_64(ipInstance, "systemPhysicalAddress",
			       node->IPInstance.systemPhysicalAddress
				       .SystemPhysicalAddress);
		break;
	case 2:
		add_int_hex_64(ipInstance, "localAddressIdentifier",
			       node->IPInstance.localAddressIdentifier
				       .SocSpecificLocalAddressSpace);
		add_int_hex_64(
			ipInstance, "baseAddress",
			node->IPInstance.localAddressIdentifier.BaseAddress);
		break;
	case 3:
		add_string(ipInstance, "socSpecificIpIdentifier",
			   "<OpaqueData>");
		break;
	}
	json_object_object_add(root, "ipInstance", ipInstance);

	const char *ipTypeFormat[] = { "PE", "SMMU_IIDR", "GIC_IIDR", "PIDR" };
	add_dict(root, "ipTypeFormat", node->IPTypeFormat, ipTypeFormat,
		 sizeof(ipTypeFormat) / sizeof(ipTypeFormat[0]));

	json_object *ipType = json_object_new_object();
	switch (node->IPTypeFormat) {
	case 0:
		add_int_hex_64(ipType, "midrEl1",
			       node->IPType.smmuIidr.MIDR_EL1);
		add_int_hex_64(ipType, "revidrEl1",
			       node->IPType.smmuIidr.REVIDR_EL1);
		add_int_hex_64(ipType, "aidrEl1",
			       node->IPType.smmuIidr.AIDR_EL1);
		break;
	case 1:
		add_int_hex_32(ipType, "iidr", node->IPType.gicIidr.IIDR);
		add_int_hex_32(ipType, "aidr", node->IPType.gicIidr.AIDR);
		break;
	case 2:
		add_int_hex_8(ipType, "pidr3", node->IPType.pidr.PIDR3);
		add_int_hex_8(ipType, "pidr2", node->IPType.pidr.PIDR2);
		add_int_hex_8(ipType, "pidr1", node->IPType.pidr.PIDR1);
		add_int_hex_8(ipType, "pidr0", node->IPType.pidr.PIDR0);
		add_int_hex_8(ipType, "pidr7", node->IPType.pidr.PIDR7);
		add_int_hex_8(ipType, "pidr6", node->IPType.pidr.PIDR6);
		add_int_hex_8(ipType, "pidr5", node->IPType.pidr.PIDR5);
		add_int_hex_8(ipType, "pidr4", node->IPType.pidr.PIDR4);
		break;
	}

	json_object_object_add(root, "ipType", ipType);

	add_untrusted_string(root, "userData", (const char *)node->UserData,
			     sizeof(node->UserData));
}

static json_object *arm_ras_parse_descriptors(const UINT8 *section,
					      const EFI_ARM_RAS_NODE *node,
					      UINT32 descriptorCount)
{
	json_object *descArrObj = json_object_new_array();
	const UINT8 *desc_ptr = section + node->ErrorSyndromeArrayOffset;

	for (UINT32 i = 0; i < descriptorCount; i++) {
		const UINT8 *cur =
			desc_ptr +
			i * sizeof(EFI_ARM_RAS_ERROR_RECORD_DESCRIPTOR);
		EFI_ARM_RAS_ERROR_RECORD_DESCRIPTOR d;
		memcpy(&d, cur, sizeof(d));
		json_object *desc = json_object_new_object();
		add_uint(desc, "errorRecordIndex", d.ErrorRecordIndex);
		add_uint(desc, "rasExtensionRevisionField",
			 (d.RasExtensionRevision >> 4) & 0x0F);
		add_uint(desc, "rasExtensionArchVersion",
			 d.RasExtensionRevision & 0x0F);
		add_int_hex_64(desc, "errorRecordFeatureRegister", d.ERR_FR);
		add_int_hex_64(desc, "errorRecordControlRegister", d.ERR_CTLR);
		add_int_hex_64(desc, "errorRecordPrimaryStatusRegister",
			       d.ERR_STATUS);
		add_int_hex_64(desc, "errorRecordAddressRegister", d.ERR_ADDR);
		add_int_hex_64(desc, "errorRecordMiscRegister0", d.ERR_MISC0);
		add_int_hex_64(desc, "errorRecordMiscRegister1", d.ERR_MISC1);
		if (d.RasExtensionRevision) {
			add_int_hex_64(desc, "errorRecordMiscRegister2",
				       d.ERR_MISC2);
			add_int_hex_64(desc, "errorRecordMiscRegister3",
				       d.ERR_MISC3);
		}
		json_object_array_add(descArrObj, desc);
	}

	return descArrObj;
}

/*
 * Validate the fixed-size ARM RAS auxiliary header fields.
 */
static bool arm_ras_aux_hdr_valid(const EFI_ARM_RAS_AUX_DATA_HEADER *auxHdr,
				  UINT32 auxLen)
{
	/*
	 * KVP array layout:
	 *   - When there are no entries, the offset must be exactly the
	 *     end of the aux blob.
	 *   - When entries are present, the offset must be somewhere inside
	 *     the aux blob (the upper bound is checked here, the lower
	 *     bound below).
	 */
	bool kvOffsetValid =
		((auxHdr->KeyValuePairArrayEntryCount == 0 &&
		  auxHdr->KeyValuePairArrayOffset ==
			  auxHdr->AuxiliaryDataSize) ||
		 (auxHdr->KeyValuePairArrayOffset < auxHdr->AuxiliaryDataSize));
	/*
	* The spec requires (Table 22):
	*   - Version must be 1
	*   - AuxiliaryDataSize is the total size of the aux block, including
	*     the header itself, and must:
	*       * fit within the remaining section buffer (<= auxLen) and
	*       * be at least large enough to hold the header.
	*/
	return (auxHdr->Version == 1) &&
	       (auxHdr->AuxiliaryDataSize <= auxLen) &&
	       (auxHdr->AuxiliaryDataSize >=
		sizeof(EFI_ARM_RAS_AUX_DATA_HEADER)) &&
	       kvOffsetValid &&
	       (auxHdr->KeyValuePairArrayOffset >=
		sizeof(EFI_ARM_RAS_AUX_DATA_HEADER));
}

static json_object *
arm_ras_aux_emit_header_fields(const EFI_ARM_RAS_AUX_DATA_HEADER *auxHdr)
{
	/* Emit auxiliary header fields in spec order (Table 22):
	 * version, reserved0 (omitted - always zero), addressSpaceArrayEntryCount,
	 * auxiliaryDataSize, keyValuePairArrayOffset, keyValuePairArrayEntryCount,
	 * reserved1 (omitted).
	 */
	json_object *auxStructured = json_object_new_object();
	add_uint(auxStructured, "version", auxHdr->Version);
	return auxStructured;
}

static bool
arm_ras_aux_parse_contexts(json_object *auxStructured, const UINT8 *aux_ptr,
			   const EFI_ARM_RAS_AUX_DATA_HEADER *auxHdr)
{
	json_object *contexts = json_object_new_array();
	const UINT8 *cursor = aux_ptr + sizeof(EFI_ARM_RAS_AUX_DATA_HEADER);
	UINT32 remaining =
		auxHdr->AuxiliaryDataSize - sizeof(EFI_ARM_RAS_AUX_DATA_HEADER);
	bool ok = true;

	for (UINT16 ci = 0; ci < auxHdr->AddressSpaceArrayEntryCount; ci++) {
		if (remaining < sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER)) {
			ok = false;
			cper_print_log(
				"ARM RAS Auxiliary Data too small for context header: %u < %zu",
				remaining,
				sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER));
			break;
		}
		const EFI_ARM_RAS_AUX_CONTEXT_HEADER *ctx =
			(const EFI_ARM_RAS_AUX_CONTEXT_HEADER *)cursor;
		if (ctx->Length < sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER)) {
			ok = false;
			cper_print_log(
				"ARM RAS Auxiliary Context length too small: %u < %zu",
				ctx->Length,
				sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER));
			break;
		}
		UINT32 needed = sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER) +
				ctx->RegisterArrayEntryCount *
					sizeof(EFI_ARM_RAS_AUX_MM_REG_ENTRY);
		if (ctx->Length < needed || needed > remaining) {
			ok = false;
			cper_print_log(
				"ARM RAS Auxiliary Context length too small or exceeds remaining data: %u < %u or %u > %u",
				ctx->Length, needed, needed, remaining);
			break;
		}
		UINT32 afterCtxOffset =
			(UINT32)(cursor - aux_ptr) + ctx->Length;
		if (afterCtxOffset > auxHdr->KeyValuePairArrayOffset) {
			ok = false;
			cper_print_log(
				"ARM RAS Auxiliary Context overlaps KVP array");
			break;
		}

		json_object *ctxObjInstance = json_object_new_object();
		json_object *flags = json_object_new_object();

		static const char *addressSpaceIdentifierScope[2] = {
			"SystemPhysicalAddressSpace",
			"LocalAddressSpace",
		};

		add_bool_enum(flags, "addressSpaceIdentifierScope",
			      addressSpaceIdentifierScope,
			      ctx->AddressSpaceIdentifierScope);
		json_object_object_add(ctxObjInstance, "flags", flags);

		if (ctx->AddressSpaceIdentifierScope == 1) {
			add_uint(ctxObjInstance, "addressSpaceIdentifier",
				 (UINT64)ctx->AddressSpaceIdentifier);
		}

		json_object *regs = json_object_new_array();
		const EFI_ARM_RAS_AUX_MM_REG_ENTRY *regArr =
			(const EFI_ARM_RAS_AUX_MM_REG_ENTRY
				 *)(cursor +
				    sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER));
		for (UINT16 ri = 0; ri < ctx->RegisterArrayEntryCount; ri++) {
			json_object *r = json_object_new_object();
			add_int_hex_64(r, "address",
				       regArr[ri].RegisterAddress);
			add_int_hex_64(r, "value", regArr[ri].RegisterValue);
			json_object_array_add(regs, r);
		}
		json_object_object_add(ctxObjInstance, "registers", regs);
		json_object_array_add(contexts, ctxObjInstance);

		cursor += ctx->Length;
		remaining -= ctx->Length;
	}

	if (ok) {
		json_object_object_add(auxStructured, "contexts", contexts);
	}

	return ok;
}

int is_mpam(EFI_GUID *key)
{
	if (guid_equal(key, &EFI_ARM_RAS_KVP_UUID_MPAM_PARTID)) {
		return 1;
	}
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
	// The exact byte used here is arbitrary.
	return key->Data4[0] % 2;
#endif
	return 0;
}

static void arm_ras_aux_parse_kvps(json_object *auxStructured,
				   const UINT8 *aux_ptr,
				   EFI_ARM_RAS_AUX_DATA_HEADER *auxHdr)
{
	const UINT8 *kvBase = aux_ptr + auxHdr->KeyValuePairArrayOffset;
	UINT32 kvAvail =
		auxHdr->AuxiliaryDataSize - auxHdr->KeyValuePairArrayOffset;
	UINT32 kvNeeded = auxHdr->KeyValuePairArrayEntryCount *
			  sizeof(EFI_ARM_RAS_AUX_KEY_VALUE_PAIR);
	if (kvNeeded > kvAvail) {
		return;
	}

	json_object *kvps = json_object_new_array();
	EFI_ARM_RAS_AUX_KEY_VALUE_PAIR *kvArr =
		(EFI_ARM_RAS_AUX_KEY_VALUE_PAIR *)kvBase;
	for (UINT16 ki = 0; ki < auxHdr->KeyValuePairArrayEntryCount; ki++) {
		json_object *kv = json_object_new_object();
		EFI_ARM_RAS_AUX_KEY_VALUE_PAIR *kvEntry = &kvArr[ki];
		EFI_GUID key = kvEntry->Key;
		add_guid(kv, "key", &key);

		if (is_mpam(&key)) {
			UINT16 partId = (UINT16)(kvEntry->Value & 0xFFFF);
			add_uint(kv, "mpamPartId", partId);
		} else {
			add_int_hex_64(kv, "value", kvEntry->Value);
		}
		json_object_array_add(kvps, kv);
	}
	json_object_object_add(auxStructured, "keyValuePairs", kvps);
}

static json_object *arm_ras_parse_aux_data(const UINT8 *section, UINT32 size,
					   const EFI_ARM_RAS_NODE *node,
					   UINT64 descBytes)
{
	if (!node->AuxiliaryDataOffset) {
		return NULL;
	}

	const UINT8 *aux_ptr = section + node->AuxiliaryDataOffset;
	if (node->AuxiliaryDataOffset < sizeof(EFI_ARM_RAS_NODE) + descBytes) {
		cper_print_log("ARM RAS aux offset overlaps descriptors");
		return NULL;
	}

	UINT32 auxLen = size - node->AuxiliaryDataOffset;
	if (auxLen < sizeof(EFI_ARM_RAS_AUX_DATA_HEADER)) {
		cper_print_log("ARM RAS Auxiliary Data too small: %u < %zu",
			       auxLen, sizeof(EFI_ARM_RAS_AUX_DATA_HEADER));
		return NULL;
	}

	EFI_ARM_RAS_AUX_DATA_HEADER *auxHdr =
		(EFI_ARM_RAS_AUX_DATA_HEADER *)aux_ptr;
	if (!arm_ras_aux_hdr_valid(auxHdr, auxLen)) {
		cper_print_log(
			"Invalid ARM RAS auxiliary header: version=%u, auxSize=%u, kvOffset=%u, kvCount=%u",
			auxHdr->Version, auxHdr->AuxiliaryDataSize,
			auxHdr->KeyValuePairArrayOffset,
			auxHdr->KeyValuePairArrayEntryCount);
		return NULL;
	}

	json_object *auxStructured = arm_ras_aux_emit_header_fields(auxHdr);
	if (!arm_ras_aux_parse_contexts(auxStructured, aux_ptr, auxHdr)) {
		return auxStructured;
	}
	arm_ras_aux_parse_kvps(auxStructured, aux_ptr, auxHdr);
	return auxStructured;
}

json_object *cper_section_arm_ras_to_ir(const UINT8 *section, UINT32 size,
					char **desc_string)
{
	EFI_ARM_RAS_NODE node;
	json_object *root = NULL;
	if (!arm_ras_read_node(&node, section, size, desc_string, &root)) {
		return root;
	}

	UINT32 descriptorCount = node.ErrorSyndromeArrayNumEntries;
	UINT64 descBytes = (UINT64)descriptorCount *
			   (UINT64)sizeof(EFI_ARM_RAS_ERROR_RECORD_DESCRIPTOR);

	arm_ras_set_desc_string_valid(desc_string);
	arm_ras_add_fixed_fields(root, &node);

	json_object *descArray =
		arm_ras_parse_descriptors(section, &node, descriptorCount);
	json_object_object_add(root, "errorSyndromes", descArray);

	json_object *auxStructured =
		arm_ras_parse_aux_data(section, size, &node, descBytes);

	if (auxStructured) {
		json_object_object_add(root, "auxData", auxStructured);
	}

	return root;
}

static void arm_ras_fill_node_fixed_fields(EFI_ARM_RAS_NODE *node,
					   json_object *section)
{
	json_object *obj = NULL;
	memset(node, 0, sizeof(*node));
	if (json_object_object_get_ex(section, "revision", &obj)) {
		node->Revision = (UINT32)json_object_get_uint64(obj);
	}
	if (json_object_object_get_ex(section, "componentType", &obj)) {
		if (json_object_object_get_ex(obj, "raw", &obj)) {
			node->ComponentType = (UINT8)json_object_get_int(obj);
		}
	}
	if (json_object_object_get_ex(section, "ipInstanceFormat", &obj)) {
		if (json_object_object_get_ex(obj, "raw", &obj)) {
			node->IPInstanceFormat =
				(UINT8)json_object_get_int(obj);
		}
	}
	if (json_object_object_get_ex(section, "ipTypeFormat", &obj)) {
		if (json_object_object_get_ex(obj, "raw", &obj)) {
			node->IPTypeFormat = (UINT8)json_object_get_int(obj);
		}
	}
}

static void arm_ras_fill_node_identifiers(EFI_ARM_RAS_NODE *node,
					  json_object *section)
{
	json_object *obj = NULL;
	if (json_object_object_get_ex(section, "ipInstance", &obj)) {
		get_value_hex_64(obj, "mpidrEl1",
				 &node->IPInstance.pe.MPIDR_EL1);
		get_value_hex_64(obj, "systemPhysicalAddress",
				 &node->IPInstance.systemPhysicalAddress
					  .SystemPhysicalAddress);
		get_value_hex_64(obj, "localAddressIdentifier",
				 &node->IPInstance.localAddressIdentifier
					  .SocSpecificLocalAddressSpace);
		get_value_hex_64(
			obj, "baseAddress",
			&node->IPInstance.localAddressIdentifier.BaseAddress);

		//get_value_hex_64(obj, "socSpecificIpIdentifier", &node->IPInstance.socSpecificIpIdentifier.SocSpecificIPIdentifier);
	}
	if (json_object_object_get_ex(section, "ipType", &obj)) {
		get_value_hex_64(obj, "midrEl1",
				 &node->IPType.smmuIidr.MIDR_EL1);
		get_value_hex_64(obj, "revidrEl1",
				 &node->IPType.smmuIidr.REVIDR_EL1);
		get_value_hex_64(obj, "aidrEl1",
				 &node->IPType.smmuIidr.AIDR_EL1);
		get_value_hex_32(obj, "iidr", &node->IPType.gicIidr.IIDR);
		get_value_hex_32(obj, "aidr", &node->IPType.gicIidr.AIDR);
		get_value_hex_8(obj, "pidr3", &node->IPType.pidr.PIDR3);
		get_value_hex_8(obj, "pidr2", &node->IPType.pidr.PIDR2);
		get_value_hex_8(obj, "pidr1", &node->IPType.pidr.PIDR1);
		get_value_hex_8(obj, "pidr0", &node->IPType.pidr.PIDR0);
		get_value_hex_8(obj, "pidr7", &node->IPType.pidr.PIDR7);
		get_value_hex_8(obj, "pidr6", &node->IPType.pidr.PIDR6);
		get_value_hex_8(obj, "pidr5", &node->IPType.pidr.PIDR5);
		get_value_hex_8(obj, "pidr4", &node->IPType.pidr.PIDR4);
	}
}

static void arm_ras_fill_node_user_data(EFI_ARM_RAS_NODE *node,
					json_object *section)
{
	json_object *t = NULL;
	if (json_object_object_get_ex(section, "userData", &t)) {
		const char *s = json_object_get_string(t);
		int len = cper_printable_string_length(s, strlen(s) + 1);

		if (len < 0) {
			cper_print_log("ARM RAS user data invalid len=%d", len);
			return;
		}
		if ((size_t)len > sizeof(node->UserData)) {
			cper_print_log("ARM RAS user data too long: %d > %zu",
				       len, sizeof(node->UserData));
			return;
		}
		memcpy(node->UserData, s, len);
		node->UserData[len] = 0;
	}
}

static void arm_ras_init_descriptor_metadata(EFI_ARM_RAS_NODE *node,
					     json_object *section,
					     json_object **descArr,
					     UINT32 *descCount,
					     UINT32 *afterDescriptors)
{
	*descArr = NULL;
	*descCount = 0;
	if (json_object_object_get_ex(section, "errorSyndromes", descArr)) {
		*descCount = json_object_array_length(*descArr);
	}
	if (*descCount > 896) {
		/*
		 * Per the RAS System Architecture (Arm IHI0100), the error_syndrome_array
		 * has at most 896 entries. Clamp larger inputs to avoid emitting
		 * non-architectural records.
		 */
		cper_print_log(
			"ARM RAS error_syndrome_array entry count too large: %u > 896; clamping to 0",
			(unsigned)*descCount);
		*descCount = 0;
	}
	/* Compute offsets */
	node->ErrorSyndromeArrayOffset = (UINT16)sizeof(EFI_ARM_RAS_NODE);
	*afterDescriptors =
		sizeof(EFI_ARM_RAS_ERROR_RECORD_DESCRIPTOR) * (*descCount) +
		node->ErrorSyndromeArrayOffset;
}

static void arm_ras_build_aux_contexts(UINT8 *builtAux, UINT16 ctxCount,
				       json_object *contextsArr,
				       UINT32 headerSize)
{
	UINT8 *cursor = builtAux + headerSize;
	for (UINT16 ci = 0; ci < ctxCount; ci++) {
		json_object *ctx = json_object_array_get_idx(contextsArr, ci);
		if (!ctx) {
			continue;
		}
		json_object *regsArr = NULL;
		json_object_object_get_ex(ctx, "registers", &regsArr);
		UINT16 regCount =
			regsArr ? (UINT16)json_object_array_length(regsArr) : 0;
		UINT32 length = (UINT32)sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER) +
				regCount * sizeof(EFI_ARM_RAS_AUX_MM_REG_ENTRY);
		EFI_ARM_RAS_AUX_CONTEXT_HEADER *ch =
			(EFI_ARM_RAS_AUX_CONTEXT_HEADER *)cursor;
		ch->Length = length;
		json_object *flagsObj = NULL;
		json_object_object_get_ex(ctx, "flags", &flagsObj);
		json_object *addressSpaceIdentifierScopeObj = NULL;
		json_object_object_get_ex(flagsObj,
					  "addressSpaceIdentifierScope",
					  &addressSpaceIdentifierScopeObj);
		const char *scope =
			json_object_get_string(addressSpaceIdentifierScopeObj);
		if (strcmp(scope, "LocalAddressSpace") == 0) {
			ch->AddressSpaceIdentifierScope = 1;
		}
		ch->AddressSpaceIdentifierScope =
			addressSpaceIdentifierScopeObj ?
				(UINT8)json_object_get_int(
					addressSpaceIdentifierScopeObj) :
				0;
		ch->Reserved0 = 0;
		ch->RegisterArrayEntryCount = regCount;
		json_object *asidObj = NULL;
		json_object_object_get_ex(ctx, "addressSpaceIdentifier",
					  &asidObj);
		memset(ch->Reserved1, 0, sizeof(ch->Reserved1));
		EFI_ARM_RAS_AUX_MM_REG_ENTRY *regEntries =
			(EFI_ARM_RAS_AUX_MM_REG_ENTRY
				 *)(cursor +
				    sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER));
		for (UINT16 ri = 0; ri < regCount; ri++) {
			json_object *r = json_object_array_get_idx(regsArr, ri);
			if (!r) {
				regEntries[ri].RegisterAddress = 0;
				regEntries[ri].RegisterValue = 0;
				continue;
			}
			get_value_hex_64(r, "address",
					 &regEntries[ri].RegisterAddress);
			get_value_hex_64(r, "value",
					 &regEntries[ri].RegisterValue);
		}
		cursor += length;
	}
}

static void arm_ras_build_aux_kvps(UINT8 *builtAux, UINT16 kvpCount,
				   json_object *kvpArr, UINT32 kvpOffset)
{
	EFI_ARM_RAS_AUX_KEY_VALUE_PAIR *kvOut =
		(EFI_ARM_RAS_AUX_KEY_VALUE_PAIR *)(builtAux + kvpOffset);
	for (UINT16 ki = 0; ki < kvpCount; ki++) {
		json_object *kv = json_object_array_get_idx(kvpArr, ki);
		if (!kv) {
			continue;
		}
		json_object *keyObj = NULL;
		json_object_object_get_ex(kv, "key", &keyObj);
		const char *key = json_object_get_string(keyObj);
		if (key) {
			string_to_guid(&kvOut[ki].Key, key);
		}
		get_value_hex_64(kv, "value", &kvOut[ki].Value);
		json_object *mpamPartIdObj = NULL;
		if (json_object_object_get_ex(kv, "mpamPartId",
					      &mpamPartIdObj)) {
			kvOut[ki].Value =
				(UINT64)json_object_get_uint64(mpamPartIdObj);
		}
	}
}

static void arm_ras_build_aux_blob(json_object *auxStructured, UINT8 **builtAux,
				   UINT32 *builtAuxLen)
{
	*builtAux = NULL;
	*builtAuxLen = 0;
	if (!auxStructured) {
		return;
	}

	json_object *contextsArr = NULL;
	json_object_object_get_ex(auxStructured, "contexts", &contextsArr);
	json_object *kvpArr = NULL;
	json_object_object_get_ex(auxStructured, "keyValuePairs", &kvpArr);
	UINT16 ctxCount =
		contextsArr ? (UINT16)json_object_array_length(contextsArr) : 0;
	UINT16 kvpCount = kvpArr ? (UINT16)json_object_array_length(kvpArr) : 0;
	/* First compute size of contexts region */
	UINT32 contextsSize = 0;
	for (UINT16 i = 0; i < ctxCount; i++) {
		json_object *ctx = json_object_array_get_idx(contextsArr, i);
		if (!ctx) {
			continue;
		}
		json_object *regsArr = NULL;
		json_object_object_get_ex(ctx, "registers", &regsArr);
		UINT16 regCount =
			regsArr ? (UINT16)json_object_array_length(regsArr) : 0;
		UINT32 length = (UINT32)sizeof(EFI_ARM_RAS_AUX_CONTEXT_HEADER) +
				regCount * sizeof(EFI_ARM_RAS_AUX_MM_REG_ENTRY);
		contextsSize += length;
	}
	UINT32 headerSize = sizeof(EFI_ARM_RAS_AUX_DATA_HEADER);
	UINT32 kvpOffset =
		headerSize + contextsSize; /* from start of aux block */
	UINT32 kvpSize = kvpCount * sizeof(EFI_ARM_RAS_AUX_KEY_VALUE_PAIR);
	UINT32 auxSize = headerSize + contextsSize + kvpSize;

	/* Per the spec, AuxiliaryDataSize can be up to 2^32, but that's extreme and unrealistic.
	 * We limit auxSize to 0xFFFF to support reasonable sizes while keeping the code simple.
	 */
	if (auxSize > 0xFFFF) {
		cper_print_log(
			"Implementation doesn't support large AuxiliaryDataSize: %u > 0xFFFF",
			auxSize);
		return;
	}

	UINT8 *buf = (UINT8 *)calloc(1, auxSize);
	if (!buf) {
		return;
	}

	EFI_ARM_RAS_AUX_DATA_HEADER *hdr = (EFI_ARM_RAS_AUX_DATA_HEADER *)buf;
	hdr->Version = 1;
	hdr->Reserved0 = 0;
	hdr->AddressSpaceArrayEntryCount = ctxCount;
	hdr->AuxiliaryDataSize = auxSize;
	hdr->KeyValuePairArrayOffset = kvpOffset;
	hdr->KeyValuePairArrayEntryCount = kvpCount;
	hdr->Reserved1 = 0;

	/* Write contexts */
	arm_ras_build_aux_contexts(buf, ctxCount, contextsArr, headerSize);
	/* Write key-value pairs */
	arm_ras_build_aux_kvps(buf, kvpCount, kvpArr, kvpOffset);

	*builtAux = buf;
	*builtAuxLen = auxSize;
}

static void arm_ras_write_descriptors(json_object *descArr, UINT32 descCount,
				      FILE *out)
{
	for (UINT32 i = 0; i < descCount; i++) {
		EFI_ARM_RAS_ERROR_RECORD_DESCRIPTOR d;
		memset(&d, 0, sizeof(d));
		json_object *dj = json_object_array_get_idx(descArr, i);
		json_object *x = NULL;
		if (json_object_object_get_ex(dj, "errorRecordIndex", &x)) {
			d.ErrorRecordIndex = json_object_get_uint64(x);
		}
		/* Reconstruct rasExtensionRevision from split fields */
		UINT8 rev = 0;
		UINT8 arch = 0;
		if (json_object_object_get_ex(dj, "rasExtensionRevisionField",
					      &x)) {
			rev = (UINT8)json_object_get_uint64(x);
		}
		if (json_object_object_get_ex(dj, "rasExtensionArchVersion",
					      &x)) {
			arch = (UINT8)json_object_get_uint64(x);
		}
		d.RasExtensionRevision = ((rev & 0x0F) << 4) | (arch & 0x0F);
		get_value_hex_64(dj, "errorRecordFeatureRegister", &d.ERR_FR);
		get_value_hex_64(dj, "errorRecordControlRegister", &d.ERR_CTLR);
		get_value_hex_64(dj, "errorRecordPrimaryStatusRegister",
				 &d.ERR_STATUS);
		get_value_hex_64(dj, "errorRecordAddressRegister", &d.ERR_ADDR);
		get_value_hex_64(dj, "errorRecordMiscRegister0", &d.ERR_MISC0);
		get_value_hex_64(dj, "errorRecordMiscRegister1", &d.ERR_MISC1);
		get_value_hex_64(dj, "errorRecordMiscRegister2", &d.ERR_MISC2);
		get_value_hex_64(dj, "errorRecordMiscRegister3", &d.ERR_MISC3);
		fwrite(&d, sizeof(d), 1, out);
	}
}

void ir_section_arm_ras_to_cper(json_object *section, FILE *out)
{
	EFI_ARM_RAS_NODE node;
	arm_ras_fill_node_fixed_fields(&node, section);
	arm_ras_fill_node_identifiers(&node, section);
	arm_ras_fill_node_user_data(&node, section);

	json_object *descArr = NULL;
	UINT32 descCount = 0;
	UINT32 afterDescriptors = 0;
	arm_ras_init_descriptor_metadata(&node, section, &descArr, &descCount,
					 &afterDescriptors);

	json_object *auxStructured = NULL;
	json_object_object_get_ex(section, "auxData", &auxStructured);
	UINT8 *builtAux = NULL;
	UINT32 builtAuxLen = 0;
	arm_ras_build_aux_blob(auxStructured, &builtAux, &builtAuxLen);
	if (builtAux) {
		/*
		 * Architecturally safe: from the RAS System Architecture (Arm IHI0100),
		 * the header is 80 bytes and each ErrorSyndromes entry is 72 bytes,
		 * with at most 896 entries. So the maximum AuxiliaryDataOffset is
		 *   80 + 896 * 72 < 2^16,
		 * and fits in the UINT16 field.
		 */
		node.AuxiliaryDataOffset = (UINT16)afterDescriptors;
	} else {
		node.AuxiliaryDataOffset = 0;
	}
	node.ErrorSyndromeArrayNumEntries = descCount; // N

	fwrite(&node, sizeof(node), 1, out);
	arm_ras_write_descriptors(descArr, descCount, out);
	if (builtAux) {
		fwrite(builtAux, builtAuxLen, 1, out);
		free(builtAux);
	}
	fflush(out);
}