sfdp: Implemented the logic needed to read the headers and basic parameter table

src/Makefile

@@ -53,6 +53,7 @@ SRC =			\
 	sam4l.c		\
 	samd.c		\
 	samx5x.c	\
+	sfdp.c      \
 	stm32f1.c	\
 	ch32f1.c	\
 	stm32f4.c	\

src/target/sfdp.c

@@ -0,0 +1,90 @@
+/*
+ * This file is part of the Black Magic Debug project.
+ *
+ * Copyright (C) 2022 1BitSquared <info@1bitsquared.com>
+ * Written by Rachel Mant <git@dragonmux.network>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include "sfdp_internal.h"
+
+#ifdef MIN
+#undef MIN
+#endif
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
+static inline size_t sfdp_memory_density_to_capacity_bits(const uint8_t *const density)
+{
+	if (SFDP_DENSITY_IS_EXPONENTIAL(density))
+		return 1U << SFDP_DENSITY_VALUE(density);
+	else /* NOLINT(readability-else-after-return) */
+		return SFDP_DENSITY_VALUE(density) + 1U;
+}
+
+static spi_parameters_s sfdp_read_basic_parameter_table(target *const t, const uint32_t address, const size_t length,
+	const read_sfdp_func sfdp_read)
+{
+	sfdp_basic_parameter_table_s parameter_table;
+	const size_t table_length = MIN(sizeof(sfdp_basic_parameter_table_s), length);
+	sfdp_read(t, address, &parameter_table, table_length);
+
+	spi_parameters_s result;
+	result.capacity = sfdp_memory_density_to_capacity_bits(parameter_table.memory_density) >> 3U;
+	for (size_t i = 0; i < SFDP_ERASE_TYPES; ++i) {
+		erase_parameters_s *erase_type = &parameter_table.erase_types[i];
+		if (erase_type->opcode == parameter_table.sector_erase_opcode) {
+			result.sector_erase_opcode = erase_type->opcode;
+			result.sector_size = SFDP_ERASE_SIZE(erase_type);
+			break;
+		}
+	}
+	result.page_size = SFDP_PAGE_SIZE(parameter_table);
+	return result;
+}
+
+bool sfdp_read_parameters(target *const t, spi_parameters_s *params, const read_sfdp_func sfdp_read)
+{
+	sfdp_header_s header;
+	sfdp_read(t, SFDP_HEADER_ADDRESS, &header, sizeof(header));
+	if (memcmp(header.magic, SFDP_MAGIC, 4) != 0)
+		return false;
+
+	for (size_t i = 0; i <= header.parameter_headers_count; ++i) {
+		sfdp_parameter_table_header_s table_header;
+		sfdp_read(t, SFDP_TABLE_HEADER_ADDRESS + (sizeof(table_header) * i), &table_header, sizeof(table_header));
+		const uint16_t jedec_parameter_id = SFDP_JEDEC_PARAMETER_ID(table_header);
+		if (jedec_parameter_id == SFDP_BASIC_SPI_PARAMETER_TABLE) {
+			const uint32_t table_address = SFDP_TABLE_ADDRESS(table_header);
+			const uint16_t table_length = table_header.table_length_in_u32s * 4U;
+			*params = sfdp_read_basic_parameter_table(t, table_address, table_length, sfdp_read);
+			return true;
+		}
+	}
+	return false;
+}