flash/stm32f1x: add support for RISC-V GigaDevice GD32VF103

The device has compatible flash macro with STM32F1 family, reuse
stm32f1x driver code.

Detect non-ARM target - for simplicy test target type name 'riscv'
and the address has 32 bits.

In case of RISC-V CPU use simple chunked write algo - async algo
cannot be used as the core implemented in this device doesn't
allow memory access while running.

Change-Id: Ie3886fbd8573652691f91a02335812a7300689f7
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/6704
Tested-by: jenkins
Reviewed-by: Tim Newsome <tim@sifive.com>

contrib/loaders/flash/gd32vf103/Makefile

@@ -0,0 +1,28 @@
+BIN2C = ../../../../src/helper/bin2char.sh
+
+CROSS_COMPILE ?= riscv-none-embed-
+
+CC=$(CROSS_COMPILE)gcc
+OBJCOPY=$(CROSS_COMPILE)objcopy
+OBJDUMP=$(CROSS_COMPILE)objdump
+
+CFLAGS = -march=rv32i -mabi=ilp32 -static -nostartfiles -nostdlib -Os -g -fPIC
+
+all: gd32vf103.inc
+
+.PHONY: clean
+
+%.elf: %.c
+	$(CC) $(CFLAGS) $< -o $@
+
+%.lst: %.elf
+	$(OBJDUMP) -S $< > $@
+
+%.bin: %.elf
+	$(OBJCOPY) -Obinary $< $@
+
+%.inc: %.bin
+	$(BIN2C) < $< > $@
+
+clean:
+	-rm -f *.elf *.lst *.bin *.inc

contrib/loaders/flash/gd32vf103/gd32vf103.c

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <stdint.h>
+
+#define FLASH_BSY	(1 << 0)
+#define FLASH_PGERR	(1 << 2)
+#define FLASH_WRPRTERR	(1 << 4)
+
+void flash_write(volatile uint32_t *flash_sr,
+		uint32_t hwords_count,
+		uint16_t *buffer,
+		uint16_t *target_addr) __attribute__((naked));
+
+void flash_write(volatile uint32_t *flash_sr,
+		uint32_t hwords_count,
+		uint16_t *buffer,
+		uint16_t *target_addr)
+{
+	do {
+		*target_addr = *buffer++;
+
+		register uint32_t sr;
+		do {
+			sr = *flash_sr;
+		} while (sr & FLASH_BSY);
+
+		if (sr & (FLASH_PGERR | FLASH_WRPRTERR))
+			break;
+
+		target_addr++;
+	} while (--hwords_count);
+	asm("ebreak");
+}

contrib/loaders/flash/gd32vf103/gd32vf103.inc

@@ -0,0 +1,4 @@
+/* Autogenerated with ../../../../src/helper/bin2char.sh */
+0x83,0x57,0x06,0x00,0x13,0x06,0x26,0x00,0x23,0x90,0xf6,0x00,0x83,0x27,0x05,0x00,
+0x13,0xf7,0x17,0x00,0xe3,0x1c,0x07,0xfe,0x93,0xf7,0x47,0x01,0x63,0x98,0x07,0x00,
+0x93,0x85,0xf5,0xff,0x93,0x86,0x26,0x00,0xe3,0x9c,0x05,0xfc,0x73,0x00,0x10,0x00,