flash/nor/stm32f1x: Add support for GD32E23x

GD32E23x from GigaDevice is cortex-M23 microcontroller and it can work with the stm32f1x driver.
Modifications are similar to this done for GD32F1x0 in #6164 (https://review.openocd.org/c/openocd/+/6164).
Configuration file is added because its cortex-M23 CPU ID is different.
I think that GigaDevice microcontrollers should be handled in an independent unit to separate them from STM32,
but nowadays quick solution is welcome.

Signed-off-by: asier70Andrzej Sierżęga <asier70@gmail.com>
Change-Id: I91f31f5f66808bc50a8f607ac2c107e6b7c5e2b8
Reviewed-on: https://review.openocd.org/c/openocd/+/6527
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

doc/openocd.texi

@@ -7120,8 +7120,8 @@ applied to all of them.
 
 @deffn {Flash Driver} {stm32f1x}
 All members of the STM32F0, STM32F1 and STM32F3 microcontroller families
-from STMicroelectronics and all members of the GD32F1x0 and GD32F3x0 microcontroller
+from STMicroelectronics and all members of the GD32F1x0, GD32F3x0 and GD32E23x microcontroller
-families from GigaDevice include internal flash and use ARM Cortex-M0/M3/M4 cores.
+families from GigaDevice include internal flash and use ARM Cortex-M0/M3/M4/M23 cores.
 The driver automatically recognizes a number of these chips using
 the chip identification register, and autoconfigures itself.
 

src/flash/nor/stm32f1x.c

@@ -640,6 +640,9 @@ static int stm32x_get_device_id(struct flash_bank *bank, uint32_t *device_id)
 	case CORTEX_M4_PARTNO: /* STM32F3x devices */
 		device_id_register = 0xE0042000;
 		break;
+	case CORTEX_M23_PARTNO: /* GD32E23x devices */
+		device_id_register = 0x40015800;
+		break;
 	default:
 		LOG_ERROR("Cannot identify target as a stm32x");
 		return ERROR_FAIL;
@@ -674,6 +677,9 @@ static int stm32x_get_flash_size(struct flash_bank *bank, uint16_t *flash_size_i
 	case CORTEX_M4_PARTNO: /* STM32F3x devices */
 		flash_size_reg = 0x1FFFF7CC;
 		break;
+	case CORTEX_M23_PARTNO: /* GD32E23x devices */
+		flash_size_reg = 0x1FFFF7E0;
+		break;
 	default:
 		LOG_ERROR("Cannot identify target as a stm32x");
 		return ERROR_FAIL;
@@ -756,8 +762,8 @@ static int stm32x_probe(struct flash_bank *bank)
 		page_size = 1024;
 		stm32x_info->ppage_size = 4;
 		max_flash_size_in_kb = 128;
-		/* GigaDevice GD32F1x0 & GD32F3x0 series devices share DEV_ID
+		/* GigaDevice GD32F1x0 & GD32F3x0 & GD32E23x series devices
-		   with STM32F101/2/3 medium-density line,
+		   share DEV_ID with STM32F101/2/3 medium-density line,
 		   however they use a REV_ID different from any STM32 device.
 		   The main difference is another offset of user option bits
 		   (like WDG_SW, nRST_STOP, nRST_STDBY) in option byte register
@@ -774,6 +780,11 @@ static int stm32x_probe(struct flash_bank *bank)
 			stm32x_info->user_data_offset = 16;
 			stm32x_info->option_offset = 6;
 			break;
+		case 0x1909: /* gd32e23x */
+			stm32x_info->user_data_offset = 16;
+			stm32x_info->option_offset = 6;
+			max_flash_size_in_kb = 64;
+			break;
 		}
 		break;
 	case 0x412: /* stm32f1x low-density */
@@ -984,6 +995,10 @@ static int get_stm32x_info(struct flash_bank *bank, struct command_invocation *c
 			device_str = "GD32F3x0";
 			break;
 
+		case 0x1909: /* gd32e23x */
+			device_str = "GD32E23x";
+			break;
+
 		case 0x2000:
 			rev_str = "B";
 			break;

src/flash/startup.tcl

@@ -121,3 +121,6 @@ proc stm32l5x args { eval stm32l4x $args }
 proc stm32u5x args { eval stm32l4x $args }
 proc stm32wbx args { eval stm32l4x $args }
 proc stm32wlx args { eval stm32l4x $args }
+
+# gd32e23x uses the same flash driver as the stm32f1x
+proc gd32e23x args { eval stm32f1x $args }

tcl/target/gd32e23x.cfg

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# script for GigaDevice gd32e23x Cortex-M23 Series
+
+# https://www.gigadevice.com/microcontroller/gd32e230c8t6/
+
+#
+# gd32e23x devices support SWD transports only.
+#
+source [find target/swj-dp.tcl]
+source [find mem_helper.tcl]
+
+if { [info exists CHIPNAME] } {
+   set _CHIPNAME $CHIPNAME
+} else {
+   set _CHIPNAME gd32e23x
+}
+
+# Work-area is a space in RAM used for flash programming
+# By default use 4kB (as found on some GD32E230s)
+if { [info exists WORKAREASIZE] } {
+   set _WORKAREASIZE $WORKAREASIZE
+} else {
+   set _WORKAREASIZE 0x1000
+}
+
+# Allow overriding the Flash bank size
+if { [info exists FLASH_SIZE] } {
+    set _FLASH_SIZE $FLASH_SIZE
+} else {
+    # autodetect size
+    set _FLASH_SIZE 0
+}
+
+#jtag scan chain
+if { [info exists CPUTAPID] } {
+   set _CPUTAPID $CPUTAPID
+} else {
+   # this is the SW-DP tap id not the jtag tap id
+   set _CPUTAPID 0x0bf11477
+}
+
+swj_newdap $_CHIPNAME cpu -irlen 4 -ircapture 0x1 -irmask 0xf -expected-id $_CPUTAPID
+dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.cpu
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME cortex_m -dap $_CHIPNAME.dap
+
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
+
+# flash size will be probed
+set _FLASHNAME $_CHIPNAME.flash
+flash bank $_FLASHNAME stm32f1x 0x08000000 $_FLASH_SIZE 0 0 $_TARGETNAME
+
+# SWD speed (may be updated to higher value in board config file)
+adapter speed 1000
+
+reset_config srst_nogate
+
+if {![using_hla]} {
+    # if srst is not fitted use SYSRESETREQ to
+    # perform a soft reset
+    cortex_m reset_config sysresetreq
+}
+
+$_TARGETNAME configure -event examine-end {
+	# Debug clock enable
+	# RCU_APB2EN |= DBGMCUEN
+	mmw 0x40021018 0x00400000 0
+
+	# Stop watchdog counters during halt
+	# DBG_CTL0 |= WWDGT_HOLD | FWDGT_HOLD | STB_HOLD | DSLP_HOLD | SLP_HOLD
+	mmw 0x40015804 0x00000307 0
+}