new file mode 100644
@@ -0,0 +1,488 @@
+From f9881d01669cd98e6f897214f407dce8a245bdfe Mon Sep 17 00:00:00 2001
+From: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+Date: Mon, 19 Feb 2024 16:01:28 +0000
+Subject: [PATCH 1/6] remoteproc: Add Arm remoteproc driver
+
+introduce remoteproc support for Arm remote processors
+
+The supported remote processors are those that come with a reset
+control register and a reset status register. The driver allows to
+switch on or off the remote processor.
+
+The current use case is Corstone-1000 External System (Cortex-M3).
+
+The driver can be extended to support other remote processors
+controlled with a reset control and a reset status registers.
+
+The driver also supports control of multiple remote processors at the
+same time.
+
+Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+Upstream-Status: Submitted [cover letter: https://lore.kernel.org/all/20240301164227.339208-1-abdellatif.elkhlifi@arm.com/]
+---
+ MAINTAINERS | 6 +
+ drivers/remoteproc/Kconfig | 18 ++
+ drivers/remoteproc/Makefile | 1 +
+ drivers/remoteproc/arm_rproc.c | 395 +++++++++++++++++++++++++++++++++
+ 4 files changed, 420 insertions(+)
+ create mode 100644 drivers/remoteproc/arm_rproc.c
+
+diff --git a/MAINTAINERS b/MAINTAINERS
+index 8d1052fa6a69..54d6a40feea5 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -1764,6 +1764,12 @@ S: Maintained
+ F: Documentation/devicetree/bindings/interrupt-controller/arm,vic.yaml
+ F: drivers/irqchip/irq-vic.c
+
++ARM REMOTEPROC DRIVER
++M: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
++L: linux-remoteproc@vger.kernel.org
++S: Maintained
++F: drivers/remoteproc/arm_rproc.c
++
+ ARM SMC WATCHDOG DRIVER
+ M: Julius Werner <jwerner@chromium.org>
+ R: Evan Benn <evanbenn@chromium.org>
+diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
+index 48845dc8fa85..57fbac454a5d 100644
+--- a/drivers/remoteproc/Kconfig
++++ b/drivers/remoteproc/Kconfig
+@@ -365,6 +365,24 @@ config XLNX_R5_REMOTEPROC
+
+ It's safe to say N if not interested in using RPU r5f cores.
+
++config ARM_REMOTEPROC
++ tristate "Arm remoteproc support"
++ depends on HAS_IOMEM && ARM64
++ default n
++ help
++ Say y here to support Arm remote processors via the remote
++ processor framework.
++
++ The supported processors are those that come with a reset control register
++ and a reset status register. The design can be extended to support different
++ processors meeting these requirements.
++ The driver also supports control of multiple remote cores at the same time.
++
++ Supported remote cores:
++ Corstone-1000 External System (Cortex-M3)
++
++ It's safe to say N here.
++
+ endif # REMOTEPROC
+
+ endmenu
+diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
+index 91314a9b43ce..73126310835b 100644
+--- a/drivers/remoteproc/Makefile
++++ b/drivers/remoteproc/Makefile
+@@ -39,3 +39,4 @@ obj-$(CONFIG_STM32_RPROC) += stm32_rproc.o
+ obj-$(CONFIG_TI_K3_DSP_REMOTEPROC) += ti_k3_dsp_remoteproc.o
+ obj-$(CONFIG_TI_K3_R5_REMOTEPROC) += ti_k3_r5_remoteproc.o
+ obj-$(CONFIG_XLNX_R5_REMOTEPROC) += xlnx_r5_remoteproc.o
++obj-$(CONFIG_ARM_REMOTEPROC) += arm_rproc.o
+diff --git a/drivers/remoteproc/arm_rproc.c b/drivers/remoteproc/arm_rproc.c
+new file mode 100644
+index 000000000000..6afa78ae7ad3
+--- /dev/null
++++ b/drivers/remoteproc/arm_rproc.c
+@@ -0,0 +1,395 @@
++// SPDX-License-Identifier: GPL-2.0-only
++/*
++ * Copyright 2024 Arm Limited and/or its affiliates <open-source-office@arm.com>
++ *
++ * Authors:
++ * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
++ */
++
++#include <linux/delay.h>
++#include <linux/err.h>
++#include <linux/firmware.h>
++#include <linux/kernel.h>
++#include <linux/module.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
++#include <linux/remoteproc.h>
++
++#include "remoteproc_internal.h"
++
++/**
++ * struct arm_rproc_reset_cfg - remote processor reset configuration
++ * @ctrl_reg: address of the control register
++ * @state_reg: address of the reset status register
++ */
++struct arm_rproc_reset_cfg {
++ void __iomem *ctrl_reg;
++ void __iomem *state_reg;
++};
++
++struct arm_rproc;
++
++/**
++ * struct arm_rproc_dcfg - Arm remote processor configuration
++ * @stop: stop callback function
++ * @start: start callback function
++ */
++struct arm_rproc_dcfg {
++ int (*stop)(struct rproc *rproc);
++ int (*start)(struct rproc *rproc);
++};
++
++/**
++ * struct arm_rproc - Arm remote processor instance
++ * @rproc: rproc handler
++ * @core_dcfg: device configuration pointer
++ * @reset_cfg: reset configuration registers
++ */
++struct arm_rproc {
++ struct rproc *rproc;
++ const struct arm_rproc_dcfg *core_dcfg;
++ struct arm_rproc_reset_cfg reset_cfg;
++};
++
++/* Definitions for Arm Corstone-1000 External System */
++
++#define EXTSYS_RST_CTRL_CPUWAIT BIT(0)
++#define EXTSYS_RST_CTRL_RST_REQ BIT(1)
++
++#define EXTSYS_RST_ACK_MASK GENMASK(2, 1)
++#define EXTSYS_RST_ST_RST_ACK(x) \
++ ((u8)(FIELD_GET(EXTSYS_RST_ACK_MASK, (x))))
++
++#define EXTSYS_RST_ACK_NO_RESET_REQ (0x0)
++#define EXTSYS_RST_ACK_NOT_COMPLETE (0x1)
++#define EXTSYS_RST_ACK_COMPLETE (0x2)
++#define EXTSYS_RST_ACK_RESERVED (0x3)
++
++#define EXTSYS_RST_ACK_POLL_TRIES (3)
++#define EXTSYS_RST_ACK_POLL_TIMEOUT (1000)
++
++/**
++ * arm_rproc_start_cs1000_extsys() - custom start function
++ * @rproc: pointer to the remote processor object
++ *
++ * Start function for Corstone-1000 External System.
++ * Allow the External System core start execute instructions.
++ *
++ * Return:
++ *
++ * 0 on success. Otherwise, failure
++ */
++static int arm_rproc_start_cs1000_extsys(struct rproc *rproc)
++{
++ struct arm_rproc *priv = rproc->priv;
++ u32 ctrl_reg;
++
++ /* CPUWAIT signal of the External System is de-asserted */
++ ctrl_reg = readl(priv->reset_cfg.ctrl_reg);
++ ctrl_reg &= ~EXTSYS_RST_CTRL_CPUWAIT;
++ writel(ctrl_reg, priv->reset_cfg.ctrl_reg);
++
++ return 0;
++}
++
++/**
++ * arm_rproc_cs1000_extsys_poll_rst_ack() - poll RST_ACK bits
++ * @rproc: pointer to the remote processor object
++ * @exp_ack: expected bits value
++ * @rst_ack: bits value read
++ *
++ * Tries to read RST_ACK bits until the timeout expires.
++ * EXTSYS_RST_ACK_POLL_TRIES tries are made,
++ * every EXTSYS_RST_ACK_POLL_TIMEOUT milliseconds.
++ *
++ * Return:
++ *
++ * 0 on success. Otherwise, failure
++ */
++static int arm_rproc_cs1000_extsys_poll_rst_ack(struct rproc *rproc,
++ u8 exp_ack, u8 *rst_ack)
++{
++ struct arm_rproc *priv = rproc->priv;
++ struct device *dev = rproc->dev.parent;
++ u32 state_reg;
++ int tries = EXTSYS_RST_ACK_POLL_TRIES;
++ unsigned long timeout;
++
++ do {
++ state_reg = readl(priv->reset_cfg.state_reg);
++ *rst_ack = EXTSYS_RST_ST_RST_ACK(state_reg);
++
++ if (*rst_ack == EXTSYS_RST_ACK_RESERVED) {
++ dev_err(dev, "unexpected RST_ACK value: 0x%x\n",
++ *rst_ack);
++ return -EINVAL;
++ }
++
++ /* expected ACK value read */
++ if ((*rst_ack & exp_ack) || (*rst_ack == exp_ack))
++ return 0;
++
++ timeout = msleep_interruptible(EXTSYS_RST_ACK_POLL_TIMEOUT);
++
++ if (timeout) {
++ dev_err(dev, "polling RST_ACK aborted\n");
++ return -ECONNABORTED;
++ }
++ } while (--tries);
++
++ dev_err(dev, "polling RST_ACK timed out\n");
++
++ return -ETIMEDOUT;
++}
++
++/**
++ * arm_rproc_stop_cs1000_extsys() - custom stop function
++ * @rproc: pointer to the remote processor object
++ *
++ * Reset all logic within the External System, the core will be in a halt state.
++ *
++ * Return:
++ *
++ * 0 on success. Otherwise, failure
++ */
++static int arm_rproc_stop_cs1000_extsys(struct rproc *rproc)
++{
++ struct arm_rproc *priv = rproc->priv;
++ struct device *dev = rproc->dev.parent;
++ u32 ctrl_reg;
++ u8 rst_ack, req_status;
++ int ret;
++
++ ctrl_reg = readl(priv->reset_cfg.ctrl_reg);
++ ctrl_reg |= EXTSYS_RST_CTRL_RST_REQ;
++ writel(ctrl_reg, priv->reset_cfg.ctrl_reg);
++
++ ret = arm_rproc_cs1000_extsys_poll_rst_ack(rproc,
++ EXTSYS_RST_ACK_COMPLETE |
++ EXTSYS_RST_ACK_NOT_COMPLETE,
++ &rst_ack);
++ if (ret)
++ return ret;
++
++ req_status = rst_ack;
++
++ ctrl_reg = readl(priv->reset_cfg.ctrl_reg);
++ ctrl_reg &= ~EXTSYS_RST_CTRL_RST_REQ;
++ writel(ctrl_reg, priv->reset_cfg.ctrl_reg);
++
++ ret = arm_rproc_cs1000_extsys_poll_rst_ack(rproc, 0, &rst_ack);
++ if (ret)
++ return ret;
++
++ if (req_status == EXTSYS_RST_ACK_COMPLETE) {
++ dev_dbg(dev, "the requested reset has been accepted\n");
++ return 0;
++ }
++
++ dev_err(dev, "the requested reset has been denied\n");
++ return -EACCES;
++}
++
++static const struct arm_rproc_dcfg arm_rproc_cfg_corstone1000_extsys = {
++ .stop = arm_rproc_stop_cs1000_extsys,
++ .start = arm_rproc_start_cs1000_extsys,
++};
++
++/**
++ * arm_rproc_stop() - Stop function for rproc_ops
++ * @rproc: pointer to the remote processor object
++ *
++ * Calls the stop() callback of the remote core
++ *
++ * Return:
++ *
++ * 0 on success. Otherwise, failure
++ */
++static int arm_rproc_stop(struct rproc *rproc)
++{
++ struct arm_rproc *priv = rproc->priv;
++
++ return priv->core_dcfg->stop(rproc);
++}
++
++/**
++ * arm_rproc_start() - Start function for rproc_ops
++ * @rproc: pointer to the remote processor object
++ *
++ * Calls the start() callback of the remote core
++ *
++ * Return:
++ *
++ * 0 on success. Otherwise, failure
++ */
++static int arm_rproc_start(struct rproc *rproc)
++{
++ struct arm_rproc *priv = rproc->priv;
++
++ return priv->core_dcfg->start(rproc);
++}
++
++/**
++ * arm_rproc_parse_fw() - Parse firmware function for rproc_ops
++ * @rproc: pointer to the remote processor object
++ * @fw: pointer to the firmware
++ *
++ * Does nothing currently.
++ *
++ * Return:
++ *
++ * 0 for success.
++ */
++static int arm_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
++{
++ return 0;
++}
++
++/**
++ * arm_rproc_load() - Load firmware to memory function for rproc_ops
++ * @rproc: pointer to the remote processor object
++ * @fw: pointer to the firmware
++ *
++ * Does nothing currently.
++ *
++ * Return:
++ *
++ * 0 for success.
++ */
++static int arm_rproc_load(struct rproc *rproc, const struct firmware *fw)
++{
++ return 0;
++}
++
++static const struct rproc_ops arm_rproc_ops = {
++ .start = arm_rproc_start,
++ .stop = arm_rproc_stop,
++ .load = arm_rproc_load,
++ .parse_fw = arm_rproc_parse_fw,
++};
++
++/**
++ * arm_rproc_probe() - the platform device probe
++ * @pdev: the platform device
++ *
++ * Read from the device tree the properties needed to setup
++ * the reset and comms for the remote processor.
++ * Also, allocate a rproc device and register it with the remoteproc subsystem.
++ *
++ * Return:
++ *
++ * 0 on success. Otherwise, failure
++ */
++static int arm_rproc_probe(struct platform_device *pdev)
++{
++ const struct arm_rproc_dcfg *core_dcfg;
++ struct device *dev = &pdev->dev;
++ struct device_node *np = dev->of_node;
++ struct arm_rproc *priv;
++ struct rproc *rproc;
++ const char *fw_name;
++ int ret;
++ struct resource *res;
++
++ core_dcfg = of_device_get_match_data(dev);
++ if (!core_dcfg)
++ return -ENODEV;
++
++ ret = rproc_of_parse_firmware(dev, 0, &fw_name);
++ if (ret) {
++ dev_err(dev,
++ "can't parse firmware-name from device tree (%pe)\n",
++ ERR_PTR(ret));
++ return ret;
++ }
++
++ dev_dbg(dev, "firmware-name: %s\n", fw_name);
++
++ rproc = rproc_alloc(dev, np->name, &arm_rproc_ops, fw_name,
++ sizeof(*priv));
++ if (!rproc)
++ return -ENOMEM;
++
++ priv = rproc->priv;
++ priv->rproc = rproc;
++ priv->core_dcfg = core_dcfg;
++
++ res = platform_get_resource_byname(pdev,
++ IORESOURCE_MEM, "reset-control");
++ priv->reset_cfg.ctrl_reg = devm_ioremap_resource(&pdev->dev, res);
++ if (IS_ERR(priv->reset_cfg.ctrl_reg)) {
++ ret = PTR_ERR(priv->reset_cfg.ctrl_reg);
++ dev_err(dev,
++ "can't map the reset-control register (%pe)\n",
++ ERR_PTR((unsigned long)priv->reset_cfg.ctrl_reg));
++ goto err_free_rproc;
++ } else {
++ dev_dbg(dev, "reset-control: %p\n", priv->reset_cfg.ctrl_reg);
++ }
++
++ res = platform_get_resource_byname(pdev,
++ IORESOURCE_MEM, "reset-status");
++ priv->reset_cfg.state_reg = devm_ioremap_resource(&pdev->dev, res);
++ if (IS_ERR(priv->reset_cfg.state_reg)) {
++ ret = PTR_ERR(priv->reset_cfg.state_reg);
++ dev_err(dev,
++ "can't map the reset-status register (%pe)\n",
++ ERR_PTR((unsigned long)priv->reset_cfg.state_reg));
++ goto err_free_rproc;
++ } else {
++ dev_dbg(dev, "reset-status: %p\n",
++ priv->reset_cfg.state_reg);
++ }
++
++ platform_set_drvdata(pdev, rproc);
++
++ ret = rproc_add(rproc);
++ if (ret) {
++ dev_err(dev, "can't add remote processor (%pe)\n",
++ ERR_PTR(ret));
++ goto err_free_rproc;
++ } else {
++ dev_dbg(dev, "remote processor added\n");
++ }
++
++ return 0;
++
++err_free_rproc:
++ rproc_free(rproc);
++
++ return ret;
++}
++
++/**
++ * arm_rproc_remove() - the platform device remove
++ * @pdev: the platform device
++ *
++ * Delete and free the resources used.
++ */
++static void arm_rproc_remove(struct platform_device *pdev)
++{
++ struct rproc *rproc = platform_get_drvdata(pdev);
++
++ rproc_del(rproc);
++ rproc_free(rproc);
++}
++
++static const struct of_device_id arm_rproc_of_match[] = {
++ { .compatible = "arm,corstone1000-extsys", .data = &arm_rproc_cfg_corstone1000_extsys },
++ {},
++};
++MODULE_DEVICE_TABLE(of, arm_rproc_of_match);
++
++static struct platform_driver arm_rproc_driver = {
++ .probe = arm_rproc_probe,
++ .remove_new = arm_rproc_remove,
++ .driver = {
++ .name = "arm-rproc",
++ .of_match_table = arm_rproc_of_match,
++ },
++};
++module_platform_driver(arm_rproc_driver);
++
++MODULE_LICENSE("GPL");
++MODULE_DESCRIPTION("Arm Remote Processor Control Driver");
++MODULE_AUTHOR("Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>");
+--
+2.25.1
+
new file mode 100644
@@ -0,0 +1,42 @@
+From 0122f194e4a6fb50750dadd08f2354e78d4dd79c Mon Sep 17 00:00:00 2001
+From: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+Date: Mon, 19 Feb 2024 16:18:37 +0000
+Subject: [PATCH 2/6] arm64: dts: Add corstone1000 external system device node
+
+add device tree node for the external system core in Corstone-1000
+
+Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+Upstream-Status: Submitted [cover letter: https://lore.kernel.org/all/20240301164227.339208-1-abdellatif.elkhlifi@arm.com/]
+---
+ arch/arm64/boot/dts/arm/corstone1000.dtsi | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/arch/arm64/boot/dts/arm/corstone1000.dtsi b/arch/arm64/boot/dts/arm/corstone1000.dtsi
+index 6ad7829f9e28..67df642363e9 100644
+--- a/arch/arm64/boot/dts/arm/corstone1000.dtsi
++++ b/arch/arm64/boot/dts/arm/corstone1000.dtsi
+@@ -1,6 +1,6 @@
+ // SPDX-License-Identifier: GPL-2.0 OR MIT
+ /*
+- * Copyright (c) 2022, Arm Limited. All rights reserved.
++ * Copyright 2022, 2024, Arm Limited and/or its affiliates <open-source-office@arm.com>
+ * Copyright (c) 2022, Linaro Limited. All rights reserved.
+ *
+ */
+@@ -157,5 +157,13 @@ mhu_seh1: mailbox@1b830000 {
+ secure-status = "okay"; /* secure-world-only */
+ status = "disabled";
+ };
++
++ extsys0: remoteproc@1a010310 {
++ compatible = "arm,corstone1000-extsys";
++ reg = <0x1a010310 0x4>,
++ <0x1a010314 0X4>;
++ reg-names = "reset-control", "reset-status";
++ firmware-name = "es_flashfw.elf";
++ };
+ };
+ };
+--
+2.25.1
+
new file mode 100644
@@ -0,0 +1,105 @@
+From af50eca3e3b408f2f1f378c1d0c48fb6c3107c8c Mon Sep 17 00:00:00 2001
+From: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+Date: Mon, 19 Feb 2024 20:47:26 +0000
+Subject: [PATCH 3/6] dt-bindings: remoteproc: Add Arm remoteproc
+
+introduce the bindings for Arm remoteproc support.
+
+Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+Upstream-Status: Submitted [cover letter: https://lore.kernel.org/all/20240301164227.339208-1-abdellatif.elkhlifi@arm.com/]
+---
+ .../bindings/remoteproc/arm,rproc.yaml | 69 +++++++++++++++++++
+ MAINTAINERS | 1 +
+ 2 files changed, 70 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/remoteproc/arm,rproc.yaml
+
+diff --git a/Documentation/devicetree/bindings/remoteproc/arm,rproc.yaml b/Documentation/devicetree/bindings/remoteproc/arm,rproc.yaml
+new file mode 100644
+index 000000000000..322197158059
+--- /dev/null
++++ b/Documentation/devicetree/bindings/remoteproc/arm,rproc.yaml
+@@ -0,0 +1,69 @@
++# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
++%YAML 1.2
++---
++$id: http://devicetree.org/schemas/remoteproc/arm,rproc.yaml#
++$schema: http://devicetree.org/meta-schemas/core.yaml#
++
++title: Arm Remoteproc Devices
++
++maintainers:
++ - Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
++
++description: |
++ Some Arm heterogeneous System-On-Chips feature remote processors that can
++ be controlled with a reset control register and a reset status register to
++ start or stop the processor.
++
++ This document defines the bindings for these remote processors.
++
++properties:
++ compatible:
++ enum:
++ - arm,corstone1000-extsys
++
++ reg:
++ minItems: 2
++ maxItems: 2
++ description: |
++ Address and size in bytes of the reset control register
++ and the reset status register.
++ Expects the registers to be in the order as above.
++ Should contain an entry for each value in 'reg-names'.
++
++ reg-names:
++ description: |
++ Required names for each of the reset registers defined in
++ the 'reg' property. Expects the names from the following
++ list, in the specified order, each representing the corresponding
++ reset register.
++ items:
++ - const: reset-control
++ - const: reset-status
++
++ firmware-name:
++ description: |
++ Default name of the firmware to load to the remote processor.
++
++required:
++ - compatible
++ - reg
++ - reg-names
++ - firmware-name
++
++additionalProperties: false
++
++examples:
++ - |
++ extsys0: remoteproc@1a010310 {
++ compatible = "arm,corstone1000-extsys";
++ reg = <0x1a010310 0x4>, <0x1a010314 0x4>;
++ reg-names = "reset-control", "reset-status";
++ firmware-name = "es0_flashfw.elf";
++ };
++
++ extsys1: remoteproc@1a010318 {
++ compatible = "arm,corstone1000-extsys";
++ reg = <0x1a010318 0x4>, <0x1a01031c 0x4>;
++ reg-names = "reset-control", "reset-status";
++ firmware-name = "es1_flashfw.elf";
++ };
+diff --git a/MAINTAINERS b/MAINTAINERS
+index 54d6a40feea5..eddaa3841a65 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -1768,6 +1768,7 @@ ARM REMOTEPROC DRIVER
+ M: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+ L: linux-remoteproc@vger.kernel.org
+ S: Maintained
++F: Documentation/devicetree/bindings/remoteproc/arm,rproc.yaml
+ F: drivers/remoteproc/arm_rproc.c
+
+ ARM SMC WATCHDOG DRIVER
+--
+2.25.1
+
new file mode 100644
@@ -0,0 +1,2 @@
+CONFIG_REMOTEPROC=y
+CONFIG_ARM_REMOTEPROC=y
@@ -37,6 +37,13 @@ SRC_URI:append:corstone1000 = " ${@bb.utils.contains('MACHINE_FEATURES', \
'', \
d)}"
+SRC_URI:append:corstone1000 = " \
+ file://extsys.cfg \
+ file://0001-remoteproc-Add-Arm-remoteproc-driver.patch \
+ file://0002-arm64-dts-Add-corstone1000-external-system-device-no.patch \
+ file://0003-dt-bindings-remoteproc-Add-Arm-remoteproc.patch \
+ "
+
# Default kernel features not needed for corstone1000
# otherwise the extra kernel modules will increase the rootfs size
# corstone1000 has limited flash memory constraints