Merge patch series "Universal Payload initial series"

Simon Glass <[email protected]> says:

Universal Payload (UPL) is an Industry Standard for firmware
components[1]. UPL is designed to improve interoperability within the
firmware industry, allowing mixing and matching of projects with less
friction and fewer project-specific implementations. UPL is
cross-platform, supporting ARM, x86 and RISC-V initially.

This series provides some initial support for this, targeting 0.9.1 and
sandbox only.

Features still to come include:
- Support for architectures
- FIT validation
- Handoff validation
- Interoperability tests

7 files changed, 1371 insertions, 0 deletions

diff --git a/boot/Kconfig b/boot/Kconfig
index 940389d4882..7ac34574079 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -745,6 +745,76 @@ config BOOTMETH_SCRIPT
 	  This provides a way to try out standard boot on an existing boot flow.
 	  It is not enabled by default to save space.
 
+config UPL
+	bool "upl - Universal Payload Specification"
+	imply CMD_UPL
+	imply UPL_READ
+	imply UPL_WRITE
+	imply SPL_UPL if SPL
+	help
+	  Provides support for UPL payloads and handoff information. U-Boot
+	  supports generating and accepting handoff information. The mkimage
+	  tool will eventually support creating payloads.
+
+if UPL
+
+config UPL_READ
+	bool "upl - Support reading a Universal Payload handoff"
+	help
+	  Provides support for decoding a UPL-format payload into a C structure
+	  which can be used elsewhere in U-Boot. This is just the reading
+	  implementation, useful for trying it out. See UPL_IN for how
+	  to tell U-Boot to actually read it on startup and use it for memory
+	  and device information, etc.
+
+config UPL_WRITE
+	bool "upl - Support writing a Universal Payload handoff"
+	help
+	  Provides support for encoding a UPL-format payload from a C structure
+	  so it can be passed to another program. This is just the writing
+	  implementation, useful for trying it out. See SPL_UPL_OUT
+	  for how to tell U-Boot SPL to actually write it before jumping to
+	  the next phase.
+
+config UPL_IN
+	bool "upl - Read the UPL handoff on startup"
+	select UPL_READ
+	help
+	  Read an SPL handoff when U-Boot starts and use it to provide
+	  devices, memory layout, etc. required by U-Boot. This allows U-Boot
+	  to function as a payload in the meaning of the specification.
+
+if SPL
+
+config SPL_UPL
+	bool "Write a UPL handoff in SPL"
+	imply SPL_UPL_OUT
+	help
+	  This tells SPL to write a UPL handoff and pass it to the next phase
+	  (e.g. to U-Boot or another program which SPL loads and runs). THis
+	  provides information to help that program run correctly and
+	  efficiently on the machine.
+
+config SPL_UPL_WRITE
+	bool  # upl - Support writing a Universal Payload handoff in SPL
+	select SPL_BLOBLIST
+	help
+	  Provides support for encoding a UPL-format payload from a C structure
+	  so it can be passed to another program. This is just the writing
+	  implementation, useful for trying it out.
+
+config SPL_UPL_OUT
+	bool "upl - Support writing a Universal Payload handoff in SPL"
+	select SPL_UPL_WRITE
+	help
+	  Provides support for encoding a UPL-format payload and passing it to
+	  the next firmware phase. This allows U-Boot SPL to function as
+	  Platform Init in the meaning of the specification.
+
+endif  # SPL
+
+endif  # UPL
+
 endif # BOOTSTD
 
 config LEGACY_IMAGE_FORMAT
diff --git a/boot/Makefile b/boot/Makefile
index dff6f99081a..f4675d6ffd5 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -43,6 +43,10 @@ endif
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += fdt_support.o
 obj-$(CONFIG_$(SPL_TPL_)FDT_SIMPLEFB) += fdt_simplefb.o
 
+obj-$(CONFIG_$(SPL_TPL_)UPL) += upl_common.o
+obj-$(CONFIG_$(SPL_TPL_)UPL_READ) += upl_read.o
+obj-$(CONFIG_$(SPL_TPL_)UPL_WRITE) += upl_write.o
+
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o
 obj-$(CONFIG_$(SPL_TPL_)FIT_SIGNATURE) += fdt_region.o
 obj-$(CONFIG_$(SPL_TPL_)FIT) += image-fit.o
diff --git a/boot/image-fit.c b/boot/image-fit.c
index 9253f81fff5..7d56f0b5e6e 100644
--- a/boot/image-fit.c
+++ b/boot/image-fit.c
@@ -36,6 +36,7 @@ DECLARE_GLOBAL_DATA_PTR;
 #include <bootm.h>
 #include <image.h>
 #include <bootstage.h>
+#include <upl.h>
 #include <u-boot/crc.h>
 
 /*****************************************************************************/
@@ -2294,6 +2295,8 @@ int fit_image_load(struct bootm_headers *images, ulong addr,
 
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_LOAD);
 
+	upl_add_image(fit, noffset, load, len);
+
 	*datap = load;
 	*lenp = len;
 	if (fit_unamep)
diff --git a/boot/upl_common.c b/boot/upl_common.c
new file mode 100644
index 00000000000..3924423abd5
--- /dev/null
+++ b/boot/upl_common.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * UPL handoff command functions
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <[email protected]>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <string.h>
+#include <upl.h>
+
+/* Names of bootmodes */
+const char *const bootmode_names[UPLBM_COUNT] = {
+	[UPLBM_FULL]	= "full",
+	[UPLBM_MINIMAL]	= "minimal",
+	[UPLBM_FAST]	= "fast",
+	[UPLBM_DIAG]	= "diag",
+	[UPLBM_DEFAULT]	= "default",
+	[UPLBM_S2]	= "s2",
+	[UPLBM_S3]	= "s3",
+	[UPLBM_S4]	= "s4",
+	[UPLBM_S5]	= "s5",
+	[UPLBM_FACTORY]	= "factory",
+	[UPLBM_FLASH]	= "flash",
+	[UPLBM_RECOVERY] = "recovery",
+};
+
+/* Names of memory usages */
+const char *const usage_names[UPLUS_COUNT] = {
+	[UPLUS_ACPI_RECLAIM]	= "acpi-reclaim",
+	[UPLUS_ACPI_NVS]	= "acpi-nvs",
+	[UPLUS_BOOT_CODE]	= "boot-code",
+	[UPLUS_BOOT_DATA]	= "boot-data",
+	[UPLUS_RUNTIME_CODE]	= "runtime-code",
+	[UPLUS_RUNTIME_DATA]	= "runtime-data",
+};
+
+/* Names of access types */
+const char *const access_types[UPLUS_COUNT] = {
+	[UPLAT_MMIO]	= "mmio",
+	[UPLAT_IO]	= "io",
+};
+
+/* Names of graphics formats */
+const char *const graphics_formats[UPLUS_COUNT] = {
+	[UPLGF_ARGB32]	= "a8r8g8b8",
+	[UPLGF_ABGR32]	= "a8b8g8r8",
+	[UPLGF_ABGR64]	= "a16b16g16r16",
+};
+
+void upl_init(struct upl *upl)
+{
+	memset(upl, '\0', sizeof(struct upl));
+	alist_init_struct(&upl->image, struct upl_image);
+	alist_init_struct(&upl->mem, struct upl_mem);
+	alist_init_struct(&upl->memmap, struct upl_memmap);
+	alist_init_struct(&upl->memres, struct upl_memres);
+}
diff --git a/boot/upl_common.h b/boot/upl_common.h
new file mode 100644
index 00000000000..cc517dc1de9
--- /dev/null
+++ b/boot/upl_common.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * UPL handoff command functions
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <[email protected]>
+ */
+
+#ifndef __UPL_COMMON_H
+#define __UPL_COMMON_H
+
+/* Names of bootmodes */
+extern const char *const bootmode_names[UPLBM_COUNT];
+
+/* Names of memory usages */
+extern const char *const usage_names[UPLUS_COUNT];
+
+/* Names of access types */
+extern const char *const access_types[UPLUS_COUNT];
+
+/* Names of graphics formats */
+extern const char *const graphics_formats[UPLUS_COUNT];
+
+#endif /* __UPL_COMMON_H */
diff --git a/boot/upl_read.c b/boot/upl_read.c
new file mode 100644
index 00000000000..5063897a132
--- /dev/null
+++ b/boot/upl_read.c
@@ -0,0 +1,588 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * UPL handoff parsing
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <[email protected]>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <log.h>
+#include <upl.h>
+#include <dm/ofnode.h>
+#include "upl_common.h"
+
+/**
+ * read_addr() - Read an address
+ *
+ * Reads an address in the correct format, either 32- or 64-bit
+ *
+ * @upl: UPL state
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @addr: Place to put the address
+ * Return: 0 if OK, -ve on error
+ */
+static int read_addr(const struct upl *upl, ofnode node, const char *prop,
+		     ulong *addrp)
+{
+	int ret;
+
+	if (upl->addr_cells == 1) {
+		u32 val;
+
+		ret = ofnode_read_u32(node, prop, &val);
+		if (!ret)
+			*addrp = val;
+	} else {
+		u64 val;
+
+		ret = ofnode_read_u64(node, prop, &val);
+		if (!ret)
+			*addrp = val;
+	}
+
+	return ret;
+}
+
+/**
+ * read_size() - Read a size
+ *
+ * Reads a size in the correct format, either 32- or 64-bit
+ *
+ * @upl: UPL state
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @addr: Place to put the size
+ * Return: 0 if OK, -ve on error
+ */
+static int read_size(const struct upl *upl, ofnode node, const char *prop,
+		     ulong *sizep)
+{
+	int ret;
+
+	if (upl->size_cells == 1) {
+		u32 val;
+
+		ret = ofnode_read_u32(node, prop, &val);
+		if (!ret)
+			*sizep = val;
+	} else {
+		u64 val;
+
+		ret = ofnode_read_u64(node, prop, &val);
+		if (!ret)
+			*sizep = val;
+	}
+
+	return ret;
+}
+
+/**
+ * ofnode_read_bitmask() - Read a bit mask from a string list
+ *
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @names: Array of names for each bit
+ * @count: Number of array entries
+ * @value: Returns resulting bit-mask value on success
+ * Return: 0 if OK, -EINVAL if a bit number is not defined, -ENOSPC if the
+ * string is too long for the (internal) buffer, -EINVAL if no such property
+ */
+static int ofnode_read_bitmask(ofnode node, const char *prop,
+			       const char *const names[], uint count,
+			       uint *valuep)
+{
+	const char **list;
+	const char **strp;
+	uint val;
+	uint bit;
+	int ret;
+
+	ret = ofnode_read_string_list(node, prop, &list);
+	if (ret < 0)
+		return log_msg_ret("rea", ret);
+
+	val = 0;
+	for (strp = list; *strp; strp++) {
+		const char *str = *strp;
+		bool found = false;
+
+		for (bit = 0; bit < count; bit++) {
+			if (!strcmp(str, names[bit])) {
+				found = true;
+				break;
+			}
+		}
+		if (found)
+			val |= BIT(bit);
+		else
+			log_warning("%s/%s: Invalid value '%s'\n",
+				    ofnode_get_name(node), prop, str);
+	}
+	*valuep = val;
+
+	return 0;
+}
+
+/**
+ * ofnode_read_value() - Read a string value as an int using a lookup
+ *
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @names: Array of names for each int value
+ * @count: Number of array entries
+ * @valuep: Returns int value read
+ * Return: 0 if OK, -EINVAL if a bit number is not defined, -ENOENT if the
+ * property does not exist
+ */
+static int ofnode_read_value(ofnode node, const char *prop,
+			     const char *const names[], uint count,
+			     uint *valuep)
+{
+	const char *str;
+	int i;
+
+	str = ofnode_read_string(node, prop);
+	if (!str)
+		return log_msg_ret("rd", -ENOENT);
+
+	for (i = 0; i < count; i++) {
+		if (!strcmp(names[i], str)) {
+			*valuep = i;
+			return 0;
+		}
+	}
+
+	log_debug("Unnamed value '%s'\n", str);
+	return log_msg_ret("val", -EINVAL);
+}
+
+static int read_uint(ofnode node, const char *prop, uint *valp)
+{
+	u32 val;
+	int ret;
+
+	ret = ofnode_read_u32(node, prop, &val);
+	if (ret)
+		return ret;
+	*valp = val;
+
+	return 0;
+}
+
+/**
+ * decode_root_props() - Decode root properties from the tree
+ *
+ * @upl: UPL state
+ * @node: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_root_props(struct upl *upl, ofnode node)
+{
+	int ret;
+
+	ret = read_uint(node, UPLP_ADDRESS_CELLS, &upl->addr_cells);
+	if (!ret)
+		ret = read_uint(node, UPLP_SIZE_CELLS, &upl->size_cells);
+	if (ret)
+		return log_msg_ret("cel", ret);
+
+	return 0;
+}
+
+/**
+ * decode_root_props() - Decode UPL parameters from the tree
+ *
+ * @upl: UPL state
+ * @node: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_params(struct upl *upl, ofnode options)
+{
+	ofnode node;
+	int ret;
+
+	node = ofnode_find_subnode(options, UPLN_UPL_PARAMS);
+	if (!ofnode_valid(node))
+		return log_msg_ret("par", -EINVAL);
+	log_debug("decoding '%s'\n", ofnode_get_name(node));
+
+	ret = read_addr(upl, node, UPLP_SMBIOS, &upl->smbios);
+	if (ret)
+		return log_msg_ret("smb", ret);
+	ret = read_addr(upl, node, UPLP_ACPI, &upl->acpi);
+	if (ret)
+		return log_msg_ret("acp", ret);
+	ret = ofnode_read_bitmask(node, UPLP_BOOTMODE, bootmode_names,
+				  UPLBM_COUNT, &upl->bootmode);
+	if (ret)
+		return log_msg_ret("boo", ret);
+	ret = read_uint(node, UPLP_ADDR_WIDTH, &upl->addr_width);
+	if (ret)
+		return log_msg_ret("add", ret);
+	ret = read_uint(node, UPLP_ACPI_NVS_SIZE, &upl->acpi_nvs_size);
+	if (ret)
+		return log_msg_ret("nvs", ret);
+
+	return 0;
+}
+
+/**
+ * decode_upl_images() - Decode /options/upl-image nodes
+ *
+ * @node: /options node in which to look for the node
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_images(struct upl *upl, ofnode options)
+{
+	ofnode node, images;
+	int ret;
+
+	images = ofnode_find_subnode(options, UPLN_UPL_IMAGE);
+	if (!ofnode_valid(images))
+		return log_msg_ret("img", -EINVAL);
+	log_debug("decoding '%s'\n", ofnode_get_name(images));
+
+	ret = read_addr(upl, images, UPLP_FIT, &upl->fit);
+	if (!ret)
+		ret = read_uint(images, UPLP_CONF_OFFSET, &upl->conf_offset);
+	if (ret)
+		return log_msg_ret("cnf", ret);
+
+	ofnode_for_each_subnode(node, images) {
+		struct upl_image img;
+
+		ret = read_addr(upl, node, UPLP_LOAD, &img.load);
+		if (!ret)
+			ret = read_size(upl, node, UPLP_SIZE, &img.size);
+		if (!ret)
+			ret = read_uint(node, UPLP_OFFSET, &img.offset);
+		img.description = ofnode_read_string(node, UPLP_DESCRIPTION);
+		if (!img.description)
+			return log_msg_ret("sim", ret);
+		if (!alist_add(&upl->image, img))
+			return log_msg_ret("img", -ENOMEM);
+	}
+
+	return 0;
+}
+
+/**
+ * decode_addr_size() - Decide a set of addr/size pairs
+ *
+ * Each base/size value from the devicetree is written to the region list
+ *
+ * @upl: UPL state
+ * @buf: Bytes to decode
+ * @size: Number of bytes to decode
+ * @regions: List of regions to process (struct memregion)
+ * Returns: number of regions found, if OK, else -ve on error
+ */
+static int decode_addr_size(const struct upl *upl, const char *buf, int size,
+			    struct alist *regions)
+{
+	const char *ptr, *end = buf + size;
+	int i;
+
+	alist_init_struct(regions, struct memregion);
+	ptr = buf;
+	for (i = 0; ptr < end; i++) {
+		struct memregion reg;
+
+		if (upl->addr_cells == 1)
+			reg.base = fdt32_to_cpu(*(u32 *)ptr);
+		else
+			reg.base = fdt64_to_cpu(*(u64 *)ptr);
+		ptr += upl->addr_cells * sizeof(u32);
+
+		if (upl->size_cells == 1)
+			reg.size = fdt32_to_cpu(*(u32 *)ptr);
+		else
+			reg.size = fdt64_to_cpu(*(u64 *)ptr);
+		ptr += upl->size_cells * sizeof(u32);
+		if (ptr > end)
+			return -ENOSPC;
+
+		if (!alist_add(regions, reg))
+			return log_msg_ret("reg", -ENOMEM);
+	}
+
+	return i;
+}
+
+/**
+ * node_matches_at() - Check if a node name matches "base@..."
+ *
+ * Return: true if the node name matches the base string followed by an @ sign;
+ * false otherwise
+ */
+static bool node_matches_at(ofnode node, const char *base)
+{
+	const char *name = ofnode_get_name(node);
+	int len = strlen(base);
+
+	return !strncmp(base, name, len) && name[len] == '@';
+}
+
+/**
+ * decode_upl_memory_node() - Decode a /memory node from the tree
+ *
+ * @upl: UPL state
+ * @node: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_memory_node(struct upl *upl, ofnode node)
+{
+	struct upl_mem mem;
+	const char *buf;
+	int size, len;
+
+	buf = ofnode_read_prop(node, UPLP_REG, &size);
+	if (!buf) {
+		log_warning("Node '%s': Missing '%s' property\n",
+			    ofnode_get_name(node), UPLP_REG);
+		return log_msg_ret("reg", -EINVAL);
+	}
+	len = decode_addr_size(upl, buf, size, &mem.region);
+	if (len < 0)
+		return log_msg_ret("buf", len);
+	mem.hotpluggable = ofnode_read_bool(node, UPLP_HOTPLUGGABLE);
+	if (!alist_add(&upl->mem, mem))
+		return log_msg_ret("mem", -ENOMEM);
+
+	return 0;
+}
+
+/**
+ * decode_upl_memmap() - Decode memory-map nodes from the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node containing the /memory-map nodes
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_memmap(struct upl *upl, ofnode root)
+{
+	ofnode node;
+
+	ofnode_for_each_subnode(node, root) {
+		struct upl_memmap memmap;
+		int size, len, ret;
+		const char *buf;
+
+		memmap.name = ofnode_get_name(node);
+		memmap.usage = 0;
+
+		buf = ofnode_read_prop(node, UPLP_REG, &size);
+		if (!buf) {
+			log_warning("Node '%s': Missing '%s' property\n",
+				    ofnode_get_name(node), UPLP_REG);
+			continue;
+		}
+
+		len = decode_addr_size(upl, buf, size, &memmap.region);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+		ret = ofnode_read_bitmask(node, UPLP_USAGE, usage_names,
+					  UPLUS_COUNT, &memmap.usage);
+		if (ret && ret != -EINVAL)	/* optional property */
+			return log_msg_ret("bit", ret);
+
+		if (!alist_add(&upl->memmap, memmap))
+			return log_msg_ret("mmp", -ENOMEM);
+	}
+
+	return 0;
+}
+
+/**
+ * decode_upl_memres() - Decode reserved-memory nodes from the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node containing the reserved-memory nodes
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_memres(struct upl *upl, ofnode root)
+{
+	ofnode node;
+
+	ofnode_for_each_subnode(node, root) {
+		struct upl_memres memres;
+		const char *buf;
+		int size, len;
+
+		log_debug("decoding '%s'\n", ofnode_get_name(node));
+		memres.name = ofnode_get_name(node);
+
+		buf = ofnode_read_prop(node, UPLP_REG, &size);
+		if (!buf) {
+			log_warning("Node '%s': Missing 'reg' property\n",
+				    ofnode_get_name(node));
+			continue;
+		}
+
+		len = decode_addr_size(upl, buf, size, &memres.region);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+		memres.no_map = ofnode_read_bool(node, UPLP_NO_MAP);
+
+		if (!alist_add(&upl->memres, memres))
+			return log_msg_ret("mre", -ENOMEM);
+	}
+
+	return 0;
+}
+
+/**
+ * decode_upl_serial() - Decode the serial node
+ *
+ * @upl: UPL state
+ * @root: Parent node contain node
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_serial(struct upl *upl, ofnode node)
+{
+	struct upl_serial *ser = &upl->serial;
+	const char *buf;
+	int len, size;
+	int ret;
+
+	ser->compatible = ofnode_read_string(node, UPLP_COMPATIBLE);
+	if (!ser->compatible) {
+		log_warning("Node '%s': Missing compatible string\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("com", -EINVAL);
+	}
+	ret = read_uint(node, UPLP_CLOCK_FREQUENCY, &ser->clock_frequency);
+	if (!ret)
+		ret = read_uint(node, UPLP_CURRENT_SPEED, &ser->current_speed);
+	if (ret)
+		return log_msg_ret("spe", ret);
+
+	buf = ofnode_read_prop(node, UPLP_REG, &size);
+	if (!buf) {
+		log_warning("Node '%s': Missing 'reg' property\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("reg", -EINVAL);
+	}
+
+	len = decode_addr_size(upl, buf, sizeof(buf), &ser->reg);
+	if (len < 0)
+		return log_msg_ret("buf", len);
+
+	/* set defaults */
+	ser->reg_io_shift = UPLD_REG_IO_SHIFT;
+	ser->reg_offset = UPLD_REG_OFFSET;
+	ser->reg_io_width = UPLD_REG_IO_WIDTH;
+	read_uint(node, UPLP_REG_IO_SHIFT, &ser->reg_io_shift);
+	read_uint(node, UPLP_REG_OFFSET, &ser->reg_offset);
+	read_uint(node, UPLP_REG_IO_WIDTH, &ser->reg_io_width);
+	read_addr(upl, node, UPLP_VIRTUAL_REG, &ser->virtual_reg);
+	ret = ofnode_read_value(node, UPLP_ACCESS_TYPE, access_types,
+				ARRAY_SIZE(access_types), &ser->access_type);
+	if (ret && ret != -ENOENT)
+		return log_msg_ret("ser", ret);
+
+	return 0;
+}
+
+/**
+ * decode_upl_graphics() - Decode graphics node
+ *
+ * @upl: UPL state
+ * @root: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_graphics(struct upl *upl, ofnode node)
+{
+	struct upl_graphics *gra = &upl->graphics;
+	const char *buf, *compat;
+	int len, size;
+	int ret;
+
+	compat = ofnode_read_string(node, UPLP_COMPATIBLE);
+	if (!compat) {
+		log_warning("Node '%s': Missing compatible string\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("com", -EINVAL);
+	}
+	if (strcmp(UPLC_GRAPHICS, compat)) {
+		log_warning("Node '%s': Ignoring compatible '%s'\n",
+			    ofnode_get_name(node), compat);
+		return 0;
+	}
+
+	buf = ofnode_read_prop(node, UPLP_REG, &size);
+	if (!buf) {
+		log_warning("Node '%s': Missing 'reg' property\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("reg", -EINVAL);
+	}
+
+	len = decode_addr_size(upl, buf, sizeof(buf), &gra->reg);
+	if (len < 0)
+		return log_msg_ret("buf", len);
+
+	ret = read_uint(node, UPLP_WIDTH, &gra->width);
+	if (!ret)
+		ret = read_uint(node, UPLP_HEIGHT, &gra->height);
+	if (!ret)
+		ret = read_uint(node, UPLP_STRIDE, &gra->stride);
+	if (!ret) {
+		ret = ofnode_read_value(node, UPLP_GRAPHICS_FORMAT,
+					graphics_formats,
+					ARRAY_SIZE(graphics_formats),
+					&gra->format);
+	}
+	if (ret)
+		return log_msg_ret("pro", ret);
+
+	return 0;
+}
+
+int upl_read_handoff(struct upl *upl, oftree tree)
+{
+	ofnode root, node;
+	int ret;
+
+	if (!oftree_valid(tree))
+		return log_msg_ret("tre", -EINVAL);
+
+	root = oftree_root(tree);
+
+	upl_init(upl);
+	ret = decode_root_props(upl, root);
+	if (ret)
+		return log_msg_ret("roo", ret);
+
+	ofnode_for_each_subnode(node, root) {
+		const char *name = ofnode_get_name(node);
+
+		log_debug("decoding '%s'\n", name);
+		if (!strcmp(UPLN_OPTIONS, name)) {
+			ret = decode_upl_params(upl, node);
+			if (ret)
+				return log_msg_ret("opt", ret);
+
+			ret = decode_upl_images(upl, node);
+		} else if (node_matches_at(node, UPLN_MEMORY)) {
+			ret = decode_upl_memory_node(upl, node);
+		} else if (!strcmp(UPLN_MEMORY_MAP, name)) {
+			ret = decode_upl_memmap(upl, node);
+		} else if (!strcmp(UPLN_MEMORY_RESERVED, name)) {
+			ret = decode_upl_memres(upl, node);
+		} else if (node_matches_at(node, UPLN_SERIAL)) {
+			ret = decode_upl_serial(upl, node);
+		} else if (node_matches_at(node, UPLN_GRAPHICS)) {
+			ret = decode_upl_graphics(upl, node);
+		} else {
+			log_debug("Unknown node '%s'\n", name);
+			ret = 0;
+		}
+		if (ret)
+			return log_msg_ret("err", ret);
+	}
+
+	return 0;
+}
diff --git a/boot/upl_write.c b/boot/upl_write.c
new file mode 100644
index 00000000000..7d637c15ba0
--- /dev/null
+++ b/boot/upl_write.c
@@ -0,0 +1,622 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * UPL handoff generation
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <[email protected]>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <log.h>
+#include <upl.h>
+#include <dm/ofnode.h>
+#include "upl_common.h"
+
+/**
+ * write_addr() - Write an address
+ *
+ * Writes an address in the correct format, either 32- or 64-bit
+ *
+ * @upl: UPL state
+ * @node: Node to write to
+ * @prop: Property name to write
+ * @addr: Address to write
+ * Return: 0 if OK, -ve on error
+ */
+static int write_addr(const struct upl *upl, ofnode node, const char *prop,
+		      ulong addr)
+{
+	int ret;
+
+	if (upl->addr_cells == 1)
+		ret = ofnode_write_u32(node, prop, addr);
+	else
+		ret = ofnode_write_u64(node, prop, addr);
+
+	return ret;
+}
+
+/**
+ * write_size() - Write a size
+ *
+ * Writes a size in the correct format, either 32- or 64-bit
+ *
+ * @upl: UPL state
+ * @node: Node to write to
+ * @prop: Property name to write
+ * @size: Size to write
+ * Return: 0 if OK, -ve on error
+ */
+static int write_size(const struct upl *upl, ofnode node, const char *prop,
+		      ulong size)
+{
+	int ret;
+
+	if (upl->size_cells == 1)
+		ret = ofnode_write_u32(node, prop, size);
+	else
+		ret = ofnode_write_u64(node, prop, size);
+
+	return ret;
+}
+
+/**
+ * ofnode_write_bitmask() - Write a bit mask as a string list
+ *
+ * @node: Node to write to
+ * @prop: Property name to write
+ * @names: Array of names for each bit
+ * @count: Number of array entries
+ * @value: Bit-mask value to write
+ * Return: 0 if OK, -EINVAL if a bit number is not defined, -ENOSPC if the
+ * string is too long for the (internal) buffer
+ */
+static int ofnode_write_bitmask(ofnode node, const char *prop,
+				const char *const names[], uint count,
+				uint value)
+{
+	char buf[128];
+	char *ptr, *end = buf + sizeof(buf);
+	uint bit;
+	int ret;
+
+	ptr = buf;
+	for (bit = 0; bit < count; bit++) {
+		if (value & BIT(bit)) {
+			const char *str = names[bit];
+			uint len;
+
+			if (!str) {
+				log_debug("Unnamed bit number %d\n", bit);
+				return log_msg_ret("bit", -EINVAL);
+			}
+			len = strlen(str) + 1;
+			if (ptr + len > end) {
+				log_debug("String array too long\n");
+				return log_msg_ret("bit", -ENOSPC);
+			}
+
+			memcpy(ptr, str, len);
+			ptr += len;
+		}
+	}
+
+	ret = ofnode_write_prop(node, prop, buf, ptr - buf, true);
+	if (ret)
+		return log_msg_ret("wri", ret);
+
+	return 0;
+}
+
+/**
+ * ofnode_write_value() - Write an int as a string value using a lookup
+ *
+ * @node: Node to write to
+ * @prop: Property name to write
+ * @names: Array of names for each int value
+ * @count: Number of array entries
+ * @value: Int value to write
+ * Return: 0 if OK, -EINVAL if a bit number is not defined, -ENOSPC if the
+ * string is too long for the (internal) buffer
+ */
+static int ofnode_write_value(ofnode node, const char *prop,
+			      const char *const names[], uint count,
+			      uint value)
+{
+	const char *str;
+	int ret;
+
+	if (value >= count) {
+		log_debug("Value of range %d\n", value);
+		return log_msg_ret("val", -ERANGE);
+	}
+	str = names[value];
+	if (!str) {
+		log_debug("Unnamed value %d\n", value);
+		return log_msg_ret("val", -EINVAL);
+	}
+	ret = ofnode_write_string(node, prop, str);
+	if (ret)
+		return log_msg_ret("wri", ret);
+
+	return 0;
+}
+
+/**
+ * add_root_props() - Add root properties to the tree
+ *
+ * @node: Node to add to
+ * Return 0 if OK, -ve on error
+ */
+static int add_root_props(const struct upl *upl, ofnode node)
+{
+	int ret;
+
+	ret = ofnode_write_u32(node, UPLP_ADDRESS_CELLS, upl->addr_cells);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_SIZE_CELLS, upl->size_cells);
+	if (ret)
+		return log_msg_ret("cel", ret);
+
+	return 0;
+}
+
+/**
+ * add_upl_params() - Add UPL parameters node
+ *
+ * @upl: UPL state
+ * @options: /options node to add to
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_params(const struct upl *upl, ofnode options)
+{
+	ofnode node;
+	int ret;
+
+	ret = ofnode_add_subnode(options, UPLN_UPL_PARAMS, &node);
+	if (ret)
+		return log_msg_ret("img", ret);
+
+	ret = write_addr(upl, node, UPLP_SMBIOS, upl->smbios);
+	if (!ret)
+		ret = write_addr(upl, node, UPLP_ACPI, upl->acpi);
+	if (!ret && upl->bootmode)
+		ret = ofnode_write_bitmask(node, UPLP_BOOTMODE, bootmode_names,
+					   UPLBM_COUNT, upl->bootmode);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_ADDR_WIDTH, upl->addr_width);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_ACPI_NVS_SIZE,
+				       upl->acpi_nvs_size);
+	if (ret)
+		return log_msg_ret("cnf", ret);
+
+	return 0;
+}
+
+/**
+ * add_upl_image() - Add /options/upl-image nodes and properties to the tree
+ *
+ * @upl: UPL state
+ * @node: /options node to add to
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_image(const struct upl *upl, ofnode options)
+{
+	ofnode node;
+	int ret, i;
+
+	ret = ofnode_add_subnode(options, UPLN_UPL_IMAGE, &node);
+	if (ret)
+		return log_msg_ret("img", ret);
+
+	if (upl->fit)
+		ret = ofnode_write_u32(node, UPLP_FIT, upl->fit);
+	if (!ret && upl->conf_offset)
+		ret = ofnode_write_u32(node, UPLP_CONF_OFFSET,
+				       upl->conf_offset);
+	if (ret)
+		return log_msg_ret("cnf", ret);
+
+	for (i = 0; i < upl->image.count; i++) {
+		const struct upl_image *img = alist_get(&upl->image, i,
+							struct upl_image);
+		ofnode subnode;
+		char name[10];
+
+		snprintf(name, sizeof(name), UPLN_IMAGE "-%d", i + 1);
+		ret = ofnode_add_subnode(node, name, &subnode);
+		if (ret)
+			return log_msg_ret("sub", ret);
+
+		ret = write_addr(upl, subnode, UPLP_LOAD, img->load);
+		if (!ret)
+			ret = write_size(upl, subnode, UPLP_SIZE, img->size);
+		if (!ret && img->offset)
+			ret = ofnode_write_u32(subnode, UPLP_OFFSET,
+					       img->offset);
+		ret = ofnode_write_string(subnode, UPLP_DESCRIPTION,
+					  img->description);
+		if (ret)
+			return log_msg_ret("sim", ret);
+	}
+
+	return 0;
+}
+
+/**
+ * buffer_addr_size() - Generate a set of addr/size pairs
+ *
+ * Each base/size value from each region is written to the buffer in a suitable
+ * format to be written to the devicetree
+ *
+ * @upl: UPL state
+ * @buf: Buffer to write to
+ * @size: Buffer size
+ * @num_regions: Number of regions to process
+ * @region: List of regions to process (struct memregion)
+ * Returns: Number of bytes written, or -ENOSPC if the buffer is too small
+ */
+static int buffer_addr_size(const struct upl *upl, char *buf, int size,
+			    uint num_regions, const struct alist *region)
+{
+	char *ptr, *end = buf + size;
+	int i;
+
+	ptr = buf;
+	for (i = 0; i < num_regions; i++) {
+		const struct memregion *reg = alist_get(region, i,
+							struct memregion);
+
+		if (upl->addr_cells == 1)
+			*(u32 *)ptr = cpu_to_fdt32(reg->base);
+		else
+			*(u64 *)ptr = cpu_to_fdt64(reg->base);
+		ptr += upl->addr_cells * sizeof(u32);
+
+		if (upl->size_cells == 1)
+			*(u32 *)ptr = cpu_to_fdt32(reg->size);
+		else
+			*(u64 *)ptr = cpu_to_fdt64(reg->size);
+		ptr += upl->size_cells * sizeof(u32);
+		if (ptr > end)
+			return -ENOSPC;
+	}
+
+	return ptr - buf;
+}
+
+/**
+ * add_upl_memory() - Add /memory nodes to the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node to contain the new /memory nodes
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_memory(const struct upl *upl, ofnode root)
+{
+	int i;
+
+	for (i = 0; i < upl->mem.count; i++) {
+		const struct upl_mem *mem = alist_get(&upl->mem, i,
+						      struct upl_mem);
+		char buf[mem->region.count * sizeof(64) * 2];
+		const struct memregion *first;
+		char name[26];
+		int ret, len;
+		ofnode node;
+
+		if (!mem->region.count) {
+			log_debug("Memory %d has no regions\n", i);
+			return log_msg_ret("reg", -EINVAL);
+		}
+		first = alist_get(&mem->region, 0, struct memregion);
+		sprintf(name, UPLN_MEMORY "@0x%lx", first->base);
+		ret = ofnode_add_subnode(root, name, &node);
+		if (ret)
+			return log_msg_ret("mem", ret);
+
+		len = buffer_addr_size(upl, buf, sizeof(buf), mem->region.count,
+				       &mem->region);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+
+		ret = ofnode_write_prop(node, UPLP_REG, buf, len, true);
+		if (!ret && mem->hotpluggable)
+			ret = ofnode_write_bool(node, UPLP_HOTPLUGGABLE,
+						mem->hotpluggable);
+		if (ret)
+			return log_msg_ret("lst", ret);
+	}
+
+	return 0;
+}
+
+/**
+ * add_upl_memmap() - Add memory-map nodes to the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node to contain the new /memory-map node and its subnodes
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_memmap(const struct upl *upl, ofnode root)
+{
+	ofnode mem_node;
+	int i, ret;
+
+	if (!upl->memmap.count)
+		return 0;
+	ret = ofnode_add_subnode(root, UPLN_MEMORY_MAP, &mem_node);
+	if (ret)
+		return log_msg_ret("img", ret);
+
+	for (i = 0; i < upl->memmap.count; i++) {
+		const struct upl_memmap *memmap = alist_get(&upl->memmap, i,
+							struct upl_memmap);
+		char buf[memmap->region.count * sizeof(64) * 2];
+		const struct memregion *first;
+		char name[26];
+		int ret, len;
+		ofnode node;
+
+		if (!memmap->region.count) {
+			log_debug("Memory %d has no regions\n", i);
+			return log_msg_ret("reg", -EINVAL);
+		}
+		first = alist_get(&memmap->region, 0, struct memregion);
+		sprintf(name, "%s@0x%lx", memmap->name, first->base);
+		ret = ofnode_add_subnode(mem_node, name, &node);
+		if (ret)
+			return log_msg_ret("memmap", ret);
+
+		len = buffer_addr_size(upl, buf, sizeof(buf),
+				       memmap->region.count, &memmap->region);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+		ret = ofnode_write_prop(node, UPLP_REG, buf, len, true);
+		if (!ret && memmap->usage)
+			ret = ofnode_write_bitmask(node, UPLP_USAGE,
+						   usage_names,
+						   UPLUS_COUNT, memmap->usage);
+		if (ret)
+			return log_msg_ret("lst", ret);
+	}
+
+	return 0;
+}
+
+/**
+ * add_upl_memres() - Add /memory-reserved nodes to the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node to contain the new node
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_memres(const struct upl *upl, ofnode root,
+			  bool skip_existing)
+{
+	ofnode mem_node;
+	int i, ret;
+
+	if (!upl->memmap.count)
+		return 0;
+	ret = ofnode_add_subnode(root, UPLN_MEMORY_RESERVED, &mem_node);
+	if (ret) {
+		if (skip_existing && ret == -EEXIST)
+			return 0;
+		return log_msg_ret("img", ret);
+	}
+
+	for (i = 0; i < upl->memres.count; i++) {
+		const struct upl_memres *memres = alist_get(&upl->memres, i,
+							struct upl_memres);
+		char buf[memres->region.count * sizeof(64) * 2];
+		const struct memregion *first;
+		char name[26];
+		int ret, len;
+		ofnode node;
+
+		if (!memres->region.count) {
+			log_debug("Memory %d has no regions\n", i);
+			return log_msg_ret("reg", -EINVAL);
+		}
+		first = alist_get(&memres->region, 0, struct memregion);
+		sprintf(name, "%s@0x%lx", memres->name, first->base);
+		ret = ofnode_add_subnode(mem_node, name, &node);
+		if (ret)
+			return log_msg_ret("memres", ret);
+
+		len = buffer_addr_size(upl, buf, sizeof(buf),
+				       memres->region.count, &memres->region);
+		ret = ofnode_write_prop(node, UPLP_REG, buf, len, true);
+		if (!ret && memres->no_map)
+			ret = ofnode_write_bool(node, UPLP_NO_MAP,
+						memres->no_map);
+		if (ret)
+			return log_msg_ret("lst", ret);
+	}
+
+	return 0;
+}
+
+/**
+ * add_upl_serial() - Add serial node
+ *
+ * @upl: UPL state
+ * @root: Parent node to contain the new node
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_serial(const struct upl *upl, ofnode root,
+			  bool skip_existing)
+{
+	const struct upl_serial *ser = &upl->serial;
+	const struct memregion *first;
+	char name[26];
+	ofnode node;
+	int ret;
+
+	if (!ser->compatible || skip_existing)
+		return 0;
+	if (!ser->reg.count)
+		return log_msg_ret("ser", -EINVAL);
+	first = alist_get(&ser->reg, 0, struct memregion);
+	sprintf(name, UPLN_SERIAL "@0x%lx", first->base);
+	ret = ofnode_add_subnode(root, name, &node);
+	if (ret)
+		return log_msg_ret("img", ret);
+	ret = ofnode_write_string(node, UPLP_COMPATIBLE, ser->compatible);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_CLOCK_FREQUENCY,
+				       ser->clock_frequency);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_CURRENT_SPEED,
+				       ser->current_speed);
+	if (!ret) {
+		char buf[16];
+		int len;
+
+		len = buffer_addr_size(upl, buf, sizeof(buf), 1, &ser->reg);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+
+		ret = ofnode_write_prop(node, UPLP_REG, buf, len, true);
+	}
+	if (!ret && ser->reg_io_shift != UPLD_REG_IO_SHIFT)
+		ret = ofnode_write_u32(node, UPLP_REG_IO_SHIFT,
+				       ser->reg_io_shift);
+	if (!ret && ser->reg_offset != UPLD_REG_OFFSET)
+		ret = ofnode_write_u32(node, UPLP_REG_OFFSET, ser->reg_offset);
+	if (!ret && ser->reg_io_width != UPLD_REG_IO_WIDTH)
+		ret = ofnode_write_u32(node, UPLP_REG_IO_WIDTH,
+				       ser->reg_io_width);
+	if (!ret && ser->virtual_reg)
+		ret = write_addr(upl, node, UPLP_VIRTUAL_REG, ser->virtual_reg);
+	if (!ret) {
+		ret = ofnode_write_value(node, UPLP_ACCESS_TYPE, access_types,
+					 ARRAY_SIZE(access_types),
+					 ser->access_type);
+	}
+	if (ret)
+		return log_msg_ret("ser", ret);
+
+	return 0;
+}
+
+/**
+ * add_upl_graphics() - Add graphics node
+ *
+ * @upl: UPL state
+ * @root: Parent node to contain the new node
+ * Return 0 if OK, -ve on error
+ */
+static int add_upl_graphics(const struct upl *upl, ofnode root)
+{
+	const struct upl_graphics *gra = &upl->graphics;
+	const struct memregion *first;
+	char name[36];
+	ofnode node;
+	int ret;
+
+	if (!gra->reg.count)
+		return log_msg_ret("gra", -ENOENT);
+	first = alist_get(&gra->reg, 0, struct memregion);
+	sprintf(name, UPLN_GRAPHICS "@0x%lx", first->base);
+	ret = ofnode_add_subnode(root, name, &node);
+	if (ret)
+		return log_msg_ret("gra", ret);
+
+	ret = ofnode_write_string(node, UPLP_COMPATIBLE, UPLC_GRAPHICS);
+	if (!ret) {
+		char buf[16];
+		int len;
+
+		len = buffer_addr_size(upl, buf, sizeof(buf), 1, &gra->reg);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+
+		ret = ofnode_write_prop(node, UPLP_REG, buf, len, true);
+	}
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_WIDTH, gra->width);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_HEIGHT, gra->height);
+	if (!ret)
+		ret = ofnode_write_u32(node, UPLP_STRIDE, gra->stride);
+	if (!ret) {
+		ret = ofnode_write_value(node, UPLP_GRAPHICS_FORMAT,
+					 graphics_formats,
+					 ARRAY_SIZE(graphics_formats),
+					 gra->format);
+	}
+	if (ret)
+		return log_msg_ret("pro", ret);
+
+	return 0;
+}
+
+int upl_write_handoff(const struct upl *upl, ofnode root, bool skip_existing)
+{
+	ofnode options;
+	int ret;
+
+	ret = add_root_props(upl, root);
+	if (ret)
+		return log_msg_ret("ad1", ret);
+	ret = ofnode_add_subnode(root, UPLN_OPTIONS, &options);
+	if (ret && ret != -EEXIST)
+		return log_msg_ret("opt", -EINVAL);
+
+	ret = add_upl_params(upl, options);
+	if (ret)
+		return log_msg_ret("ad1", ret);
+
+	ret = add_upl_image(upl, options);
+	if (ret)
+		return log_msg_ret("ad2", ret);
+
+	ret = add_upl_memory(upl, root);
+	if (ret)
+		return log_msg_ret("ad3", ret);
+
+	ret = add_upl_memmap(upl, root);
+	if (ret)
+		return log_msg_ret("ad4", ret);
+
+	ret = add_upl_memres(upl, root, skip_existing);
+	if (ret)
+		return log_msg_ret("ad5", ret);
+
+	ret = add_upl_serial(upl, root, skip_existing);
+	if (ret)
+		return log_msg_ret("ad6", ret);
+
+	ret = add_upl_graphics(upl, root);
+	if (ret && ret != -ENOENT)
+		return log_msg_ret("ad6", ret);
+
+	return 0;
+}
+
+int upl_create_handoff_tree(const struct upl *upl, oftree *treep)
+{
+	ofnode root;
+	oftree tree;
+	int ret;
+
+	ret = oftree_new(&tree);
+	if (ret)
+		return log_msg_ret("new", ret);
+
+	root = oftree_root(tree);
+	if (!ofnode_valid(root))
+		return log_msg_ret("roo", -EINVAL);
+
+	ret = upl_write_handoff(upl, root, false);
+	if (ret)
+		return log_msg_ret("wr", ret);
+
+	*treep = tree;
+
+	return 0;
+}