target, flash: prepare infrastructure for multi-block blank check

'flash erase_check' command runs a check algorithm on a target
if possible. The algorithm is run repeatedly for each flash sector.
Unfortunately every start and stop of the algorithm impose not negligible
overhead.
In practice it means checking is faster than plain read only for
sectors of size approx 4 kByte or bigger. And checking sectors
as short as 512 bytes runs approx 4 times slower than plain read.

The patch changes API call target_blank_check_memory() and related
to take an array of sectors (or arbitrary memory blocks).

Changes in target-specific checking routines are kept minimal.
They use only the first block from the array and process it by
the unchanged algorithm.

default_flash_blank_check() routine repeats target_blank_check_memory()
until all blocks are checked, so it works with both multi-block
and single-block based checkers.

Change-Id: I0e6c60f2d71364c9c07c09416b04de9268807f5e
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4297
Tested-by: jenkins
Reviewed-by: Andreas Bolsch <hyphen0break@gmail.com>

src/flash/nor/at91sam7.c

@@ -639,14 +639,6 @@ static int at91sam7_read_part_info(struct flash_bank *bank)
 
 static int at91sam7_erase_check(struct flash_bank *bank)
 {
-	struct target *target = bank->target;
-	uint16_t retval;
-	uint32_t blank;
-	uint16_t fast_check;
-	uint8_t *buffer;
-	uint16_t nSector;
-	uint16_t nByte;
-
 	if (bank->target->state != TARGET_HALTED) {
 		LOG_ERROR("Target not halted");
 		return ERROR_TARGET_NOT_HALTED;
@@ -656,45 +648,7 @@ static int at91sam7_erase_check(struct flash_bank *bank)
 	at91sam7_read_clock_info(bank);
 	at91sam7_set_flash_mode(bank, FMR_TIMING_FLASH);
 
-	fast_check = 1;
+	return default_flash_blank_check(bank);
-	for (nSector = 0; nSector < bank->num_sectors; nSector++) {
-		retval = target_blank_check_memory(target,
-				bank->base + bank->sectors[nSector].offset,
-				bank->sectors[nSector].size,
-				&blank, bank->erased_value);
-		if (retval != ERROR_OK) {
-			fast_check = 0;
-			break;
-		}
-		if (blank == 0xFF)
-			bank->sectors[nSector].is_erased = 1;
-		else
-			bank->sectors[nSector].is_erased = 0;
-	}
-
-	if (fast_check)
-		return ERROR_OK;
-
-	LOG_USER("Running slow fallback erase check - add working memory");
-
-	buffer = malloc(bank->sectors[0].size);
-	for (nSector = 0; nSector < bank->num_sectors; nSector++) {
-		bank->sectors[nSector].is_erased = 1;
-		retval = target_read_memory(target, bank->base + bank->sectors[nSector].offset, 4,
-				bank->sectors[nSector].size/4, buffer);
-		if (retval != ERROR_OK)
-			return retval;
-
-		for (nByte = 0; nByte < bank->sectors[nSector].size; nByte++) {
-			if (buffer[nByte] != 0xFF) {
-				bank->sectors[nSector].is_erased = 0;
-				break;
-			}
-		}
-	}
-	free(buffer);
-
-	return ERROR_OK;
 }
 
 static int at91sam7_protect_check(struct flash_bank *bank)

src/flash/nor/core.c

@@ -339,36 +339,49 @@ int default_flash_blank_check(struct flash_bank *bank)
 	struct target *target = bank->target;
 	int i;
 	int retval;
-	int fast_check = 0;
-	uint32_t blank;
 
 	if (bank->target->state != TARGET_HALTED) {
 		LOG_ERROR("Target not halted");
 		return ERROR_TARGET_NOT_HALTED;
 	}
 
-	for (i = 0; i < bank->num_sectors; i++) {
+	struct target_memory_check_block *block_array;
-		uint32_t address = bank->base + bank->sectors[i].offset;
+	block_array = malloc(bank->num_sectors * sizeof(struct target_memory_check_block));
-		uint32_t size = bank->sectors[i].size;
+	if (block_array == NULL)
+		return default_flash_mem_blank_check(bank);
 
-		retval = target_blank_check_memory(target, address, size, &blank, bank->erased_value);
+	for (i = 0; i < bank->num_sectors; i++) {
-		if (retval != ERROR_OK) {
+		block_array[i].address = bank->base + bank->sectors[i].offset;
-			fast_check = 0;
+		block_array[i].size = bank->sectors[i].size;
+		block_array[i].result = UINT32_MAX; /* erase state unknown */
+	}
+
+	bool fast_check = true;
+	for (i = 0; i < bank->num_sectors; ) {
+		retval = target_blank_check_memory(target,
+				block_array + i, bank->num_sectors - i,
+				bank->erased_value);
+		if (retval < 1) {
+			/* Run slow fallback if the first run gives no result
+			 * otherwise use possibly incomplete results */
+			if (i == 0)
+				fast_check = false;
 			break;
 		}
-		if (blank == bank->erased_value)
+		i += retval; /* add number of blocks done this round */
-			bank->sectors[i].is_erased = 1;
-		else
-			bank->sectors[i].is_erased = 0;
-		fast_check = 1;
 	}
 
-	if (!fast_check) {
+	if (fast_check) {
+		for (i = 0; i < bank->num_sectors; i++)
+			bank->sectors[i].is_erased = block_array[i].result;
+		retval = ERROR_OK;
+	} else {
 		LOG_USER("Running slow fallback erase check - add working memory");
-		return default_flash_mem_blank_check(bank);
+		retval = default_flash_mem_blank_check(bank);
 	}
+	free(block_array);
 
-	return ERROR_OK;
+	return retval;
 }
 
 /* Manipulate given flash region, selecting the bank according to target

src/target/arm.h

@@ -308,7 +308,7 @@ int armv4_5_run_algorithm_inner(struct target *target,
 int arm_checksum_memory(struct target *target,
 		target_addr_t address, uint32_t count, uint32_t *checksum);
 int arm_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value);
 
 void arm_set_cpsr(struct arm *arm, uint32_t cpsr);
 struct reg *arm_reg_current(struct arm *arm, unsigned regnum);

src/target/armv4_5.c

@@ -1663,7 +1663,7 @@ cleanup:
  *
  */
 int arm_blank_check_memory(struct target *target,
-	target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+	struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value)
 {
 	struct working_area *check_algorithm;
 	struct reg_param reg_params[3];
@@ -1706,10 +1706,10 @@ int arm_blank_check_memory(struct target *target,
 	arm_algo.core_state = ARM_STATE_ARM;
 
 	init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);
-	buf_set_u32(reg_params[0].value, 0, 32, address);
+	buf_set_u32(reg_params[0].value, 0, 32, blocks[0].address);
 
 	init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);
-	buf_set_u32(reg_params[1].value, 0, 32, count);
+	buf_set_u32(reg_params[1].value, 0, 32, blocks[0].size);
 
 	init_reg_param(&reg_params[2], "r2", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[2].value, 0, 32, erased_value);
@@ -1724,7 +1724,7 @@ int arm_blank_check_memory(struct target *target,
 			10000, &arm_algo);
 
 	if (retval == ERROR_OK)
-		*blank = buf_get_u32(reg_params[2].value, 0, 32);
+		blocks[0].result = buf_get_u32(reg_params[2].value, 0, 32);
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);
@@ -1733,7 +1733,10 @@ int arm_blank_check_memory(struct target *target,
 cleanup:
 	target_free_working_area(target, check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;       /* only one block has been checked */
 }
 
 static int arm_full_context(struct target *target)

src/target/armv7m.c

@@ -733,7 +733,7 @@ cleanup:
 
 /** Checks whether a memory region is erased. */
 int armv7m_blank_check_memory(struct target *target,
-	target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+	struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value)
 {
 	struct working_area *erase_check_algorithm;
 	struct reg_param reg_params[3];
@@ -774,10 +774,10 @@ int armv7m_blank_check_memory(struct target *target,
 	armv7m_info.core_mode = ARM_MODE_THREAD;
 
 	init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);
-	buf_set_u32(reg_params[0].value, 0, 32, address);
+	buf_set_u32(reg_params[0].value, 0, 32, blocks->address);
 
 	init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);
-	buf_set_u32(reg_params[1].value, 0, 32, count);
+	buf_set_u32(reg_params[1].value, 0, 32, blocks->size);
 
 	init_reg_param(&reg_params[2], "r2", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[2].value, 0, 32, erased_value);
@@ -793,7 +793,7 @@ int armv7m_blank_check_memory(struct target *target,
 			&armv7m_info);
 
 	if (retval == ERROR_OK)
-		*blank = buf_get_u32(reg_params[2].value, 0, 32);
+		blocks->result = buf_get_u32(reg_params[2].value, 0, 32);
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);
@@ -802,7 +802,10 @@ int armv7m_blank_check_memory(struct target *target,
 cleanup:
 	target_free_working_area(target, erase_check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;	/* only one block checked */
 }
 
 int armv7m_maybe_skip_bkpt_inst(struct target *target, bool *inst_found)

src/target/armv7m.h

@@ -225,7 +225,7 @@ int armv7m_restore_context(struct target *target);
 int armv7m_checksum_memory(struct target *target,
 		target_addr_t address, uint32_t count, uint32_t *checksum);
 int armv7m_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value);
 
 int armv7m_maybe_skip_bkpt_inst(struct target *target, bool *inst_found);
 

src/target/mips32.c

@@ -827,7 +827,8 @@ int mips32_checksum_memory(struct target *target, target_addr_t address,
 
 /** Checks whether a memory region is erased. */
 int mips32_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+		struct target_memory_check_block *blocks, int num_blocks,
+		uint8_t erased_value)
 {
 	struct working_area *erase_check_algorithm;
 	struct reg_param reg_params[3];
@@ -866,16 +867,16 @@ int mips32_blank_check_memory(struct target *target,
 	int retval = target_write_buffer(target, erase_check_algorithm->address,
 						sizeof(erase_check_code), erase_check_code_8);
 	if (retval != ERROR_OK)
-		return retval;
+		goto cleanup;
 
 	mips32_info.common_magic = MIPS32_COMMON_MAGIC;
 	mips32_info.isa_mode = isa ? MIPS32_ISA_MMIPS32 : MIPS32_ISA_MIPS32;
 
 	init_reg_param(&reg_params[0], "r4", 32, PARAM_OUT);
-	buf_set_u32(reg_params[0].value, 0, 32, address);
+	buf_set_u32(reg_params[0].value, 0, 32, blocks[0].address);
 
 	init_reg_param(&reg_params[1], "r5", 32, PARAM_OUT);
-	buf_set_u32(reg_params[1].value, 0, 32, count);
+	buf_set_u32(reg_params[1].value, 0, 32, blocks[0].size);
 
 	init_reg_param(&reg_params[2], "r6", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[2].value, 0, 32, erased_value);
@@ -884,15 +885,19 @@ int mips32_blank_check_memory(struct target *target,
 			erase_check_algorithm->address + (sizeof(erase_check_code) - 4), 10000, &mips32_info);
 
 	if (retval == ERROR_OK)
-		*blank = buf_get_u32(reg_params[2].value, 0, 32);
+		blocks[0].result = buf_get_u32(reg_params[2].value, 0, 32);
 
 	destroy_reg_param(&reg_params[0]);
 	destroy_reg_param(&reg_params[1]);
 	destroy_reg_param(&reg_params[2]);
 
+cleanup:
 	target_free_working_area(target, erase_check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;       /* only one block has been checked */
 }
 
 static int mips32_verify_pointer(struct command_context *cmd_ctx,

src/target/mips32.h

@@ -428,6 +428,6 @@ int mips32_get_gdb_reg_list(struct target *target,
 int mips32_checksum_memory(struct target *target, target_addr_t address,
 		uint32_t count, uint32_t *checksum);
 int mips32_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value);
 
 #endif /* OPENOCD_TARGET_MIPS32_H */

src/target/stm8.c

@@ -1750,7 +1750,7 @@ static int stm8_examine(struct target *target)
 
 /** Checks whether a memory region is erased. */
 static int stm8_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t count, uint32_t *blank, uint8_t erased_value)
+		struct target_memory_check_block *blocks, int num_blocks, uint8_t erased_value)
 {
 	struct working_area *erase_check_algorithm;
 	struct reg_param reg_params[2];
@@ -1778,10 +1778,10 @@ static int stm8_blank_check_memory(struct target *target,
 	stm8_info.common_magic = STM8_COMMON_MAGIC;
 
 	init_mem_param(&mem_params[0], 0x0, 3, PARAM_OUT);
-	buf_set_u32(mem_params[0].value, 0, 24, address);
+	buf_set_u32(mem_params[0].value, 0, 24, blocks[0].address);
 
 	init_mem_param(&mem_params[1], 0x3, 3, PARAM_OUT);
-	buf_set_u32(mem_params[1].value, 0, 24, count);
+	buf_set_u32(mem_params[1].value, 0, 24, blocks[0].size);
 
 	init_reg_param(&reg_params[0], "a", 32, PARAM_IN_OUT);
 	buf_set_u32(reg_params[0].value, 0, 32, erased_value);
@@ -1795,7 +1795,7 @@ static int stm8_blank_check_memory(struct target *target,
 			10000, &stm8_info);
 
 	if (retval == ERROR_OK)
-		*blank = (*(reg_params[0].value) == 0xff);
+		blocks[0].result = (*(reg_params[0].value) == 0xff);
 
 	destroy_mem_param(&mem_params[0]);
 	destroy_mem_param(&mem_params[1]);
@@ -1803,7 +1803,10 @@ static int stm8_blank_check_memory(struct target *target,
 
 	target_free_working_area(target, erase_check_algorithm);
 
-	return retval;
+	if (retval != ERROR_OK)
+		return retval;
+
+	return 1;	/* only one block has been checked */
 }
 
 static int stm8_checksum_memory(struct target *target, target_addr_t address,

src/target/target.c

@@ -2253,21 +2253,19 @@ int target_checksum_memory(struct target *target, target_addr_t address, uint32_
 	return retval;
 }
 
-int target_blank_check_memory(struct target *target, target_addr_t address, uint32_t size, uint32_t* blank,
+int target_blank_check_memory(struct target *target,
+	struct target_memory_check_block *blocks, int num_blocks,
 	uint8_t erased_value)
 {
-	int retval;
 	if (!target_was_examined(target)) {
 		LOG_ERROR("Target not examined yet");
 		return ERROR_FAIL;
 	}
 
-	if (target->type->blank_check_memory == 0)
+	if (target->type->blank_check_memory == NULL)
 		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 
-	retval = target->type->blank_check_memory(target, address, size, blank, erased_value);
+	return target->type->blank_check_memory(target, blocks, num_blocks, erased_value);
-
-	return retval;
 }
 
 int target_read_u64(struct target *target, target_addr_t address, uint64_t *value)

src/target/target.h

@@ -312,6 +312,12 @@ struct target_timer_callback {
 	struct target_timer_callback *next;
 };
 
+struct target_memory_check_block {
+	target_addr_t address;
+	uint32_t size;
+	uint32_t result;
+};
+
 int target_register_commands(struct command_context *cmd_ctx);
 int target_examine(void);
 
@@ -585,7 +591,8 @@ int target_read_buffer(struct target *target,
 int target_checksum_memory(struct target *target,
 		target_addr_t address, uint32_t size, uint32_t *crc);
 int target_blank_check_memory(struct target *target,
-		target_addr_t address, uint32_t size, uint32_t *blank, uint8_t erased_value);
+		struct target_memory_check_block *blocks, int num_blocks,
+		uint8_t erased_value);
 int target_wait_state(struct target *target, enum target_state state, int ms);
 
 /**

src/target/target_type.h

@@ -130,8 +130,9 @@ struct target_type {
 
 	int (*checksum_memory)(struct target *target, target_addr_t address,
 			uint32_t count, uint32_t *checksum);
-	int (*blank_check_memory)(struct target *target, target_addr_t address,
+	int (*blank_check_memory)(struct target *target,
-			uint32_t count, uint32_t *blank, uint8_t erased_value);
+			struct target_memory_check_block *blocks, int num_blocks,
+			uint8_t erased_value);
 
 	/*
 	 * target break-/watchpoint control