[PATCH 1/4] RISC-V: Add support for riscv kexec/kdump on kexec-tools

Björn Töpel
2025-04-09T20:14:57Z

From: Nick Kossifidis <mick@ics.forth.gr>

This patch adds support for loading the ELF kernel image. It parses
the current/provided device tree to determine the system's memory
layout, and /proc/iomem for the various kernel segments.

Tested on Qemu's rv64 virt machine and SoC of T-Head RISC-V Xuantie
910 CPU.

Now, some history: The first stab at supporting kexec-tools on RISC-V
was done by Nick Kossifidis. The initial patch has since then had a
number of improvements/fixes by other authors. Given, this is the
first commit for RISC-V, carrying the fixes/changes commits in the
upstream tree does not really add anything (bisectability).

Instead all the fixes that were applied to Nick's first commit is
outlined below:

Yixun Lan, and Xianting Tian:
* Fixed a failure to fail to find free memory area for dtb load when
using initrd image [1].
* Fixed memory range size calculation in
kexec/arch/riscv/crashdump-riscv.c:85

Simon Horman:
* RISC-V: distribute purgatory/riscv/Makefile

Include purgatory/riscv/Makefile in distribution tarball.

Local patch as it is planned to suggest this as a fix for the
patch that introduced this problem. [2]

Song Shuai:
* RISC-V: Fix the undeclared ‘EM_RISCV’ build failure

Use local `elf.h` instead of `linux/elf.h` to fix this build
error:

```
kexec/arch/riscv/crashdump-riscv.c:17:13: error: ‘EM_RISCV’ undeclared here (not in a function); did you mean ‘EM_CRIS’?
.machine = EM_RISCV,
^~~~~~~~
EM_CRIS
```

* RISC-V: Correct the usage of command line option

RISC-V process OPT_CMDLINE with the "command-line" partten, but
the riscv_opts_usage shows the "cmdline" option. So correct the
usage's output.

* RISC-V: Use linux,usable-memory-range for crash kernel

Now we use "memeory::linux,usable-memory" to indicate the
available memory for the crash kernel.

While booting with UEFI, the crash kernel would use efi.memmap to
re-populate memblock and then first kernel's memory would be
corrputed. Consequently, the /proc/vmcore file failed to create in
my local test.

And according to "chosen" dtschema [3], the available memory for
the crash kernel should be held via
"chosen::linux,usable-memory-range" property which will re-cap
memblock even after UEFI's re-population.

* RISC-V: Get memory ranges from iomem

When booting with UEFI, Linux marks the Runtime Code/Data memory
as no-map and then exports it to "Reserved" iomem_resource.

Kexc-tools uses dtb_get_memory_ranges() function to get memory
ranges via parsing dtb, but it can't see the Reserved EFI Runtime
memory. That would corrupt EFI Runtime memory and fail the kexeced
kernel to deal EFI stuff.

In my test, the kexeced kernel warned "efi: System table signature
incorrect!" and then paniced at efi_call_rts() due to the null
efi.runtime.

So we should use /proc/iomem to get memory ranges.

Björn Töpel:
* Massaged this commit message!
* Fixed up the build, by adding missing RV stub.
* RISC-V: Only cap the upper/end usable memory window

When loading the initrd in the kexec_load flow, memory for the
segments are searched from end to start. Only the max_usable
should be capped, after a successful initrd addtion.

Currently min/max usable is set to the same value, making it
impossible from subsequent segment allocations to success.

* RISC-V: Make get_memory_ranges() properly exclude "Reserved"
regions

The get_memory_ranges() did not exclude "Reserved" regions from
"System RAM" regions. It simply added "Reserved" as IOMEM, and
IOMEM is not considered when looking for holes to place kexec
segments.

Instead, do a two pass of the /proc/iomem file. First pass, adds
all the "System RAM" memory, and the second pass removes all
intersecting "Reserved" regions.

[1] https://lore.kernel.org/linux-riscv/CALecT5gQWn0PRO4Q24b6qkrfVE5OxsCp65TuhWTb30ceK_OJ0A@mail.gmail.com/
[2] https://lore.kernel.org/kexec/20221020031548.47587-1-xianting.tian@linux.alibaba.com/
[3] https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/chosen.yaml

Tested-by: Yixun Lan <yixun.lan@gmail.com>
Co-developed-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Co-developed-by: Yixun Lan <yixun.lan@gmail.com>
Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Simon Horman <horms@kernel.org>
Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
---
configure.ac | 3 +
include/elf.h | 1 +
kexec/Makefile | 1 +
kexec/arch/riscv/Makefile | 35 ++
kexec/arch/riscv/crashdump-riscv.c | 140 ++++++++
kexec/arch/riscv/include/arch/options.h | 43 +++
kexec/arch/riscv/iomem.h | 10 +
kexec/arch/riscv/kexec-elf-riscv.c | 255 ++++++++++++++
kexec/arch/riscv/kexec-riscv.c | 431 +++++++++++++++++++++++
kexec/arch/riscv/kexec-riscv.h | 32 ++
kexec/dt-ops.c | 442 +++++++++++++++++++++++-
kexec/dt-ops.h | 7 +
kexec/kexec-syscall.h | 4 +
purgatory/Makefile | 1 +
purgatory/arch/riscv/Makefile | 7 +
15 files changed, 1411 insertions(+), 1 deletion(-)
create mode 100644 kexec/arch/riscv/Makefile
create mode 100644 kexec/arch/riscv/crashdump-riscv.c
create mode 100644 kexec/arch/riscv/include/arch/options.h
create mode 100644 kexec/arch/riscv/iomem.h
create mode 100644 kexec/arch/riscv/kexec-elf-riscv.c
create mode 100644 kexec/arch/riscv/kexec-riscv.c
create mode 100644 kexec/arch/riscv/kexec-riscv.h
create mode 100644 purgatory/arch/riscv/Makefile

diff --git a/configure.ac b/configure.ac
index 43cdb64bc91b..fa96d1782f4f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -61,6 +61,9 @@ case $target_cpu in
loongarch*)
ARCH="loongarch"
;;
+ riscv32|riscv64)
+ ARCH="riscv"
+ ;;
* )
AC_MSG_ERROR([unsupported architecture $target_cpu])
;;
diff --git a/include/elf.h b/include/elf.h
index 1c8d2ccf6d26..93a5ee5eeffa 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -259,6 +259,7 @@ typedef struct
#define EM_ARC_A5 93 /* ARC Cores Tangent-A5 */
#define EM_XTENSA 94 /* Tensilica Xtensa Architecture */
#define EM_AARCH64 183 /* ARM AARCH64 */
+#define EM_RISCV 243 /* RISC-V */
#define EM_LOONGARCH 258 /* Loongson Loongarch*/
#define EM_NUM 184

diff --git a/kexec/Makefile b/kexec/Makefile
index e969d1e18c5a..8b5851decaea 100644
--- a/kexec/Makefile
+++ b/kexec/Makefile
@@ -92,6 +92,7 @@ include $(srcdir)/kexec/arch/mips/Makefile
include $(srcdir)/kexec/arch/cris/Makefile
include $(srcdir)/kexec/arch/ppc/Makefile
include $(srcdir)/kexec/arch/ppc64/Makefile
+include $(srcdir)/kexec/arch/riscv/Makefile
include $(srcdir)/kexec/arch/s390/Makefile
include $(srcdir)/kexec/arch/sh/Makefile
include $(srcdir)/kexec/arch/x86_64/Makefile
diff --git a/kexec/arch/riscv/Makefile b/kexec/arch/riscv/Makefile
new file mode 100644
index 000000000000..f26cc9025e77
--- /dev/null
+++ b/kexec/arch/riscv/Makefile
@@ -0,0 +1,35 @@
+#
+# kexec riscv
+#
+riscv_KEXEC_SRCS = kexec/arch/riscv/kexec-riscv.c
+riscv_KEXEC_SRCS += kexec/arch/riscv/kexec-elf-riscv.c
+riscv_KEXEC_SRCS += kexec/arch/riscv/crashdump-riscv.c
+
+riscv_MEM_REGIONS = kexec/mem_regions.c
+
+riscv_DT_OPS += kexec/dt-ops.c
+
+riscv_ARCH_REUSE_INITRD =
+
+riscv_CPPFLAGS += -I $(srcdir)/kexec/
+
+dist += kexec/arch/riscv/Makefile $(riscv_KEXEC_SRCS) \
+ kexec/arch/riscv/kexec-riscv.h \
+ kexec/arch/riscv/include/arch/options.h
+
+ifdef HAVE_LIBFDT
+
+LIBS += -lfdt
+
+else
+
+include $(srcdir)/kexec/libfdt/Makefile.libfdt
+
+libfdt_SRCS += $(LIBFDT_SRCS:%=kexec/libfdt/%)
+
+riscv_CPPFLAGS += -I$(srcdir)/kexec/libfdt
+
+riscv_KEXEC_SRCS += $(libfdt_SRCS)
+
+endif
+
diff --git a/kexec/arch/riscv/crashdump-riscv.c b/kexec/arch/riscv/crashdump-riscv.c
new file mode 100644
index 000000000000..336d7a7f5646
--- /dev/null
+++ b/kexec/arch/riscv/crashdump-riscv.c
@@ -0,0 +1,140 @@
+#include <errno.h>
+#include <elf.h>
+#include <unistd.h>
+
+#include "kexec.h"
+#include "crashdump.h"
+#include "kexec-elf.h"
+#include "mem_regions.h"
+
+static struct crash_elf_info elf_info = {
+#if __riscv_xlen == 64
+ .class = ELFCLASS64,
+#else
+ .class = ELFCLASS32,
+#endif
+ .data = ELFDATA2LSB,
+ .machine = EM_RISCV,
+};
+
+static struct memory_ranges crash_mem_ranges = {0};
+struct memory_range elfcorehdr_mem = {0};
+
+static unsigned long long get_page_offset(struct kexec_info *info)
+{
+ unsigned long long vaddr_off = 0;
+ unsigned long long page_size = sysconf(_SC_PAGESIZE);
+ unsigned long long init_start = get_kernel_sym("_sinittext");
+
+ /*
+ * Begining of init section is aligned to page size
+ */
+ vaddr_off = init_start - page_size;
+
+ return vaddr_off;
+}
+
+int load_elfcorehdr(struct kexec_info *info)
+{
+ struct memory_range crashkern_range = {0};
+ struct memory_range *ranges = NULL;
+ unsigned long start = 0;
+ unsigned long end = 0;
+ unsigned long buf_size = 0;
+ unsigned long elfcorehdr_addr = 0;
+ void* buf = NULL;
+ int i = 0;
+ int ret = 0;
+
+ ret = parse_iomem_single("Kernel code\n", &start, NULL);
+ if (ret) {
+ fprintf(stderr, "Cannot determine kernel physical base addr\n");
+ return -EINVAL;
+ }
+ elf_info.kern_paddr_start = start;
+
+ ret = parse_iomem_single("Kernel bss\n", NULL, &end);
+ if (ret) {
+ fprintf(stderr, "Cannot determine kernel physical bss addr\n");
+ return -EINVAL;
+ }
+ elf_info.kern_paddr_start = start;
+ elf_info.kern_size = end - start;
+
+ elf_info.kern_vaddr_start = get_kernel_sym("_text");
+ if (!elf_info.kern_vaddr_start) {
+ elf_info.kern_vaddr_start = UINT64_MAX;
+ }
+
+ elf_info.page_offset = get_page_offset(info);
+ dbgprintf("page_offset: %016llx\n", elf_info.page_offset);
+
+ ret = parse_iomem_single("Crash kernel\n", &start, &end);
+ if (ret) {
+ fprintf(stderr, "Cannot determine kernel physical bss addr\n");
+ return -EINVAL;
+ }
+ crashkern_range.start = start;
+ crashkern_range.end = end;
+ crashkern_range.type = RANGE_RESERVED;
+
+ ranges = info->memory_range;
+ for (i = 0; i < info->memory_ranges; i++) {
+ ret = mem_regions_alloc_and_add(&crash_mem_ranges,
+ ranges[i].start,
+ ranges[i].end - ranges[i].start + 1,
+ ranges[i].type);
+ if (ret ) {
+ fprintf(stderr, "Could not create crash_mem_ranges\n");
+ return ret;
+ }
+ }
+
+ ret = mem_regions_alloc_and_exclude(&crash_mem_ranges,
+ &crashkern_range);
+ if (ret) {
+ fprintf(stderr, "Could not exclude crashkern_range\n");
+ return ret;
+ }
+
+#if __riscv_xlen == 64
+ crash_create_elf64_headers(info, &elf_info, crash_mem_ranges.ranges,
+ crash_mem_ranges.size, &buf, &buf_size,
+ ELF_CORE_HEADER_ALIGN);
+
+#else
+ crash_create_elf32_headers(info, &elf_info, crash_mem_ranges.ranges,
+ crash_mem_ranges.size, &buf, &buf_size,
+ ELF_CORE_HEADER_ALIGN);
+#endif
+
+
+ elfcorehdr_addr = add_buffer_phys_virt(info, buf, buf_size,
+ buf_size, 0,
+ crashkern_range.start,
+ crashkern_range.end,
+ -1, 0);
+
+ elfcorehdr_mem.start = elfcorehdr_addr;
+ elfcorehdr_mem.end = elfcorehdr_addr + buf_size - 1;
+
+ dbgprintf("%s: elfcorehdr 0x%llx-0x%llx\n", __func__,
+ elfcorehdr_mem.start, elfcorehdr_mem.end);
+
+ return 0;
+}
+
+int is_crashkernel_mem_reserved(void)
+{
+ uint64_t start = 0;
+ uint64_t end = 0;
+
+ return parse_iomem_single("Crash kernel\n", &start, &end) == 0 ?
+ (start != end) : 0;
+}
+
+int get_crash_kernel_load_range(uint64_t *start, uint64_t *end)
+{
+ return parse_iomem_single("Crash kernel\n", start, end);
+}
+
diff --git a/kexec/arch/riscv/include/arch/options.h b/kexec/arch/riscv/include/arch/options.h
new file mode 100644
index 000000000000..7c24184b1f3e
--- /dev/null
+++ b/kexec/arch/riscv/include/arch/options.h
@@ -0,0 +1,43 @@
+#ifndef KEXEC_ARCH_RISCV_OPTIONS_H
+#define KEXEC_ARCH_RISCV_OPTIONS_H
+
+#define OPT_APPEND ((OPT_MAX)+0)
+#define OPT_DTB ((OPT_MAX)+1)
+#define OPT_INITRD ((OPT_MAX)+2)
+#define OPT_CMDLINE ((OPT_MAX)+3)
+#define OPT_REUSE_CMDLINE ((OPT_MAX)+4)
+#define OPT_ARCH_MAX ((OPT_MAX)+5)
+
+/* Options relevant to the architecture (excluding loader-specific ones),
+ * in this case none:
+ */
+#define KEXEC_ARCH_OPTIONS \
+ KEXEC_OPTIONS \
+ { "append", 1, 0, OPT_APPEND}, \
+ { "dtb", 1, 0, OPT_DTB }, \
+ { "initrd", 1, 0, OPT_INITRD }, \
+ { "command-line", 1, 0, OPT_CMDLINE}, \
+ { "reuse-cmdline", 0, NULL, OPT_REUSE_CMDLINE }, \
+
+
+#define KEXEC_ARCH_OPT_STR KEXEC_OPT_STR ""
+
+/* The following two #defines list ALL of the options added by all of the
+ * architecture's loaders.
+ * o main() uses this complete list to scan for its options, ignoring
+ * arch-specific/loader-specific ones.
+ * o Then, arch_process_options() uses this complete list to scan for its
+ * options, ignoring general/loader-specific ones.
+ * o Then, the file_type[n].load re-scans for options, using
+ * KEXEC_ARCH_OPTIONS plus its loader-specific options subset.
+ * Any unrecognised options cause an error here.
+ *
+ * This is done so that main()'s/arch_process_options()'s getopt_long() calls
+ * don't choose a kernel filename from random arguments to options they don't
+ * recognise -- as they now recognise (if not act upon) all possible options.
+ */
+#define KEXEC_ALL_OPTIONS KEXEC_ARCH_OPTIONS
+
+#define KEXEC_ALL_OPT_STR KEXEC_ARCH_OPT_STR
+
+#endif /* KEXEC_ARCH_RISCV_OPTIONS_H */
diff --git a/kexec/arch/riscv/iomem.h b/kexec/arch/riscv/iomem.h
new file mode 100644
index 000000000000..7671e26a9594
--- /dev/null
+++ b/kexec/arch/riscv/iomem.h
@@ -0,0 +1,10 @@
+#ifndef IOMEM_H
+#define IOMEM_H
+
+#define SYSTEM_RAM "System RAM\n"
+#define KERNEL_CODE "Kernel code\n"
+#define KERNEL_DATA "Kernel data\n"
+#define CRASH_KERNEL "Crash kernel\n"
+#define IOMEM_RESERVED "Reserved\n"
+
+#endif
diff --git a/kexec/arch/riscv/kexec-elf-riscv.c b/kexec/arch/riscv/kexec-elf-riscv.c
new file mode 100644
index 000000000000..f3c011c4c1dc
--- /dev/null
+++ b/kexec/arch/riscv/kexec-elf-riscv.c
@@ -0,0 +1,255 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 FORTH-ICS/CARV
+ * Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#include "kexec.h"
+#include "dt-ops.h" /* For dtb_set/clear_initrd() */
+#include <elf.h> /* For ELF header handling */
+#include <errno.h> /* For EFBIG/EINVAL */
+#include <unistd.h> /* For getpagesize() */
+#include "kexec-syscall.h" /* For KEXEC_ON_CRASH */
+#include "kexec-riscv.h"
+
+
+/*********\
+* HELPERS *
+\*********/
+
+/*
+ * Go through the available physical memory regions and
+ * find one that can hold an image of the specified size.
+ * Note: This is called after get_memory_ranges so
+ * info->memory_range[] should be populated. Also note that
+ * memory ranges are sorted, so we'll return the first region
+ * that's big enough for holding the image.
+ */
+static int elf_riscv_find_pbase(struct kexec_info *info, off_t *addr,
+ off_t size)
+{
+ int i = 0;
+ off_t start = 0;
+ off_t end = 0;
+ int ret = 0;
+
+ /*
+ * If this image is for a crash kernel, use the region
+ * the primary kernel has already reserved for us.
+ */
+ if (info->kexec_flags & KEXEC_ON_CRASH) {
+ ret = get_crash_kernel_load_range((uint64_t *) &start,
+ (uint64_t *) &end);
+ if (!ret) {
+ /*
+ * Kernel should be aligned to the nearest
+ * hugepage (2MB for RV64, 4MB for RV32).
+ */
+#if __riscv_xlen == 64
+ start = _ALIGN_UP(start, 0x200000);
+#else
+ start = _ALIGN_UP(start, 0x400000);
+#endif
+ if (end > start && ((end - start) >= size)) {
+ *addr = start;
+ return 0;
+ }
+
+ return -EFBIG;
+ } else
+ return ENOCRASHKERNEL;
+ }
+
+ for (i = 0; i < info->memory_ranges; i++) {
+ if (info->memory_range[i].type != RANGE_RAM)
+ continue;
+
+ start = info->memory_range[i].start;
+ end = info->memory_range[i].end;
+
+#if __riscv_xlen == 64
+ start = _ALIGN_UP(start, 0x200000);
+#else
+ start = _ALIGN_UP(start, 0x400000);
+#endif
+
+ if (end > start && ((end - start) >= size)) {
+ *addr = start;
+ return 0;
+ }
+ }
+
+ return -EFBIG;
+}
+
+/**************\
+* ENTRY POINTS *
+\**************/
+
+int elf_riscv_probe(const char *buf, off_t len)
+{
+ struct mem_ehdr ehdr = {0};
+ int ret = 0;
+
+ ret = build_elf_exec_info(buf, len, &ehdr, 0);
+ if (ret < 0)
+ goto cleanup;
+
+ if (ehdr.e_machine != EM_RISCV) {
+ fprintf(stderr, "Not for this architecture.\n");
+ ret = -EINVAL;
+ goto cleanup;
+ }
+
+ ret = 0;
+
+ cleanup:
+ free_elf_info(&ehdr);
+ return ret;
+}
+
+void elf_riscv_usage(void)
+{
+}
+
+int elf_riscv_load(int argc, char **argv, const char *buf, off_t len,
+ struct kexec_info *info)
+{
+ struct mem_ehdr ehdr = {0};
+ struct mem_phdr *phdr = NULL;
+ off_t new_base_addr = 0;
+ off_t kernel_size = 0;
+ off_t page_size = getpagesize();
+ off_t max_addr = 0;
+ off_t old_base_addr = 0;
+ off_t old_start_addr = 0;
+ int i = 0;
+ int ret = 0;
+
+ if (info->file_mode) {
+ fprintf(stderr, "kexec_file not supported on this "
+ "architecture\n");
+ return -EINVAL;
+ }
+
+ /* Parse the ELF file */
+ ret = build_elf_exec_info(buf, len, &ehdr, 0);
+ if (ret < 0) {
+ fprintf(stderr, "ELF exec parse failed\n");
+ return -EINVAL;
+ }
+
+ max_addr = elf_max_addr(&ehdr);
+ old_base_addr = max_addr;
+ old_start_addr = max_addr;
+
+ /*
+ * Get the memory footprint, base physical
+ * and start address of the ELF image
+ */
+ for (i = 0; i < ehdr.e_phnum; i++) {
+ phdr = &ehdr.e_phdr[i];
+ if (phdr->p_type != PT_LOAD)
+ continue;
+
+ /*
+ * Note: According to ELF spec the loadable regions
+ * are sorted on p_vaddr, not p_paddr.
+ */
+ if (old_base_addr > phdr->p_paddr)
+ old_base_addr = phdr->p_paddr;
+
+ if (phdr->p_vaddr == ehdr.e_entry ||
+ phdr->p_paddr == ehdr.e_entry)
+ old_start_addr = phdr->p_paddr;
+
+ kernel_size += _ALIGN_UP(phdr->p_memsz, page_size);
+ }
+
+ if (old_base_addr == max_addr || kernel_size == 0) {
+ fprintf(stderr, "No loadable segments present on the "
+ "provided ELF image\n");
+ return -EINVAL;
+ }
+
+ if (old_start_addr == max_addr) {
+ fprintf(stderr, "Could not find the entry point address of "
+ "provided ELF image\n");
+ return -EINVAL;
+ }
+
+ dbgprintf("Got ELF with total memsz %luKB\n"
+ "Base paddr: 0x%lX, start_addr: 0x%lX\n",
+ kernel_size / 1024, old_base_addr, old_start_addr);
+
+ /* Get a continuous physical region that can hold the kernel */
+ ret = elf_riscv_find_pbase(info, &new_base_addr, kernel_size);
+ if (ret < 0) {
+ fprintf(stderr, "Could not find a memory region for the "
+ "provided ELF image\n");
+ return ret;
+ }
+
+ dbgprintf("New base paddr for the ELF: 0x%lX\n", new_base_addr);
+
+ /* Re-set the base physical address of the ELF */
+ for (i = 0; i < ehdr.e_phnum; i++) {
+ phdr = &ehdr.e_phdr[i];
+ if (phdr->p_type != PT_LOAD)
+ continue;
+
+ phdr->p_paddr -= old_base_addr;
+ phdr->p_paddr += new_base_addr;
+ }
+
+ /* Re-set the entry point address */
+ ehdr.e_entry = (old_start_addr - old_base_addr) + new_base_addr;
+ info->entry = (void *) ehdr.e_entry;
+ dbgprintf("New entry point for the ELF: 0x%llX\n", ehdr.e_entry);
+
+
+ /* Load the ELF executable */
+ ret = elf_exec_load(&ehdr, info);
+ if (ret < 0) {
+ fprintf(stderr, "ELF exec load failed\n");
+ return ret;
+ }
+
+ ret = load_extra_segments(info, new_base_addr,
+ kernel_size, max_addr);
+ return ret;
+}
+
+
+/*******\
+* STUBS *
+\*******/
+
+int machine_verify_elf_rel(struct mem_ehdr *ehdr)
+{
+ if (ehdr->ei_data != ELFDATA2LSB)
+ return 0;
+#if __riscv_xlen == 64
+ if (ehdr->ei_class != ELFCLASS64)
+#else
+ if (ehdr->ei_class != ELFCLASS32)
+#endif
+ return 0;
+ if (ehdr->e_machine != EM_RISCV)
+ return 0;
+ return 1;
+}
+
+void machine_apply_elf_rel(struct mem_ehdr *UNUSED(ehdr),
+ struct mem_sym *UNUSED(sym),
+ unsigned long r_type,
+ void *UNUSED(location),
+ unsigned long UNUSED(address),
+ unsigned long UNUSED(value))
+{
+ switch (r_type) {
+ default:
+ die("Unknown rela relocation: %lu\n", r_type);
+ break;
+ }
+}
diff --git a/kexec/arch/riscv/kexec-riscv.c b/kexec/arch/riscv/kexec-riscv.c
new file mode 100644
index 000000000000..38d9a394aadd
--- /dev/null
+++ b/kexec/arch/riscv/kexec-riscv.c
@@ -0,0 +1,431 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 FORTH-ICS/CARV
+ * Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+#include "kexec-syscall.h" /* For KEXEC_ARCH_RISCV */
+#include "kexec.h" /* For OPT_MAX and concat_cmdline() */
+#include "mem_regions.h" /* For mem_regions_sort() */
+#include "dt-ops.h" /* For dtb_set_bootargs() */
+#include <arch/options.h> /* For KEXEC_ARCH_OPTIONS */
+#include <getopt.h> /* For struct option */
+#include <sys/stat.h> /* For stat() and struct stat */
+#include <stdlib.h> /* For free() */
+#include <errno.h> /* For EINVAL */
+#include <libfdt.h> /* For DeviceTree handling */
+#include "kexec-riscv.h"
+#include "iomem.h"
+#include <stdbool.h>
+
+const struct arch_map_entry arches[] = {
+ { "riscv32", KEXEC_ARCH_RISCV },
+ { "riscv64", KEXEC_ARCH_RISCV },
+ { NULL, 0 },
+};
+
+
+struct file_type file_type[] = {
+ {"elf-riscv", elf_riscv_probe, elf_riscv_load, elf_riscv_usage},
+};
+int file_types = sizeof(file_type) / sizeof(file_type[0]);
+
+static const char riscv_opts_usage[] =
+" --append=STRING Append STRING to the kernel command line.\n"
+" --dtb=FILE Use FILE as the device tree blob.\n"
+" --initrd=FILE Use FILE as the kernel initial ramdisk.\n"
+" --command-line=STRING Use STRING as the kernel's command line.\n"
+" --reuse-cmdline Use kernel command line from running system.\n";
+
+static struct riscv_opts arch_options = {0};
+static struct fdt_image provided_fdt = {0};
+
+/****************\
+* COMMON HELPERS *
+\****************/
+
+int load_extra_segments(struct kexec_info *info, uint64_t kernel_base,
+ uint64_t kernel_size, uint64_t max_addr)
+{
+ struct fdt_image *fdt = arch_options.fdt;
+ char *initrd_buf = NULL;
+ off_t initrd_size = 0;
+ uint64_t initrd_base = 0;
+ uint64_t start = 0;
+ uint64_t end = 0;
+ uint64_t min_usable = kernel_base + kernel_size;
+ uint64_t max_usable = max_addr;
+ int ret = 0;
+
+ /* Prepare the device tree */
+ if (info->kexec_flags & KEXEC_ON_CRASH) {
+ ret = load_elfcorehdr(info);
+ if (ret) {
+ fprintf(stderr, "Couldn't create elfcorehdr\n");
+ return ret;
+ }
+
+ ret = dtb_add_range_property(&fdt->buf, &fdt->size,
+ elfcorehdr_mem.start, elfcorehdr_mem.end,
+ "chosen", "linux,elfcorehdr");
+ if (ret) {
+ fprintf(stderr, "Couldn't add elfcorehdr to fdt\n");
+ return ret;
+ }
+
+ ret = get_crash_kernel_load_range(&start, &end);
+ if (ret) {
+ fprintf(stderr, "Couldn't get crashkenel region\n");
+ return ret;
+ }
+
+ ret = dtb_add_range_property(&fdt->buf, &fdt->size, start, end,
+ "chosen", "linux,usable-memory-range");
+ if (ret) {
+ fprintf(stderr, "Couldn't add usable-memory-range to fdt\n");
+ return ret;
+ }
+
+ max_usable = end;
+ } else {
+ /*
+ * Make sure we remove elfcorehdr and usable-memory-range
+ * when switching from crash kernel to a normal one.
+ */
+ dtb_delete_property(fdt->buf, "chosen", "linux,elfcorehdr");
+ dtb_delete_property(fdt->buf, "chosen", "linux,usable-memory-range");
+ }
+
+ /* Do we need to include an initrd image ? */
+ if (!arch_options.initrd_path && !arch_options.initrd_end)
+ dtb_clear_initrd(&fdt->buf, &fdt->size);
+ else if (arch_options.initrd_path) {
+ if (arch_options.initrd_end)
+ fprintf(stderr, "Warning: An initrd image was provided"
+ ", will ignore reuseinitrd\n");
+
+ initrd_buf = slurp_file(arch_options.initrd_path,
+ &initrd_size);
+ if (!initrd_buf) {
+ fprintf(stderr, "Couldn't read provided initrd\n");
+ return -EINVAL;
+ }
+
+ initrd_base = add_buffer_phys_virt(info, initrd_buf,
+ initrd_size,
+ initrd_size, 0,
+ min_usable,
+ max_usable, -1, 0);
+
+ dtb_set_initrd(&fdt->buf, &fdt->size, initrd_base,
+ initrd_base + initrd_size);
+
+ dbgprintf("Base addr for initrd image: 0x%lX\n", initrd_base);
+ max_usable = initrd_base;
+ }
+
+ /* Add device tree */
+ add_buffer_phys_virt(info, fdt->buf, fdt->size, fdt->size, 0,
+ min_usable, max_usable, -1, 0);
+
+ return 0;
+}
+
+
+/**************\
+* ENTRY POINTS *
+\**************/
+
+void arch_usage(void)
+{
+ printf(riscv_opts_usage);
+}
+
+int arch_process_options(int argc, char **argv)
+{
+ static const struct option options[] = {
+ KEXEC_ARCH_OPTIONS
+ { 0 },
+ };
+ static const char short_options[] = KEXEC_ARCH_OPT_STR;
+ struct stat st = {0};
+ char *append = NULL;
+ char *cmdline = NULL;
+ void *tmp = NULL;
+ off_t tmp_size = 0;
+ int opt = 0;
+ int ret = 0;
+
+ while ((opt = getopt_long(argc, argv, short_options,
+ options, 0)) != -1) {
+ switch (opt) {
+ case OPT_APPEND:
+ append = optarg;
+ break;
+ case OPT_CMDLINE:
+ if (cmdline)
+ fprintf(stderr,
+ "Warning: Kernel's cmdline "
+ "set twice !\n");
+ cmdline = optarg;
+ break;
+ case OPT_REUSE_CMDLINE:
+ if (cmdline)
+ fprintf(stderr,
+ "Warning: Kernel's cmdline "
+ "set twice !\n");
+ cmdline = get_command_line();
+ break;
+ case OPT_DTB:
+ ret = stat(optarg, &st);
+ if (ret) {
+ fprintf(stderr,
+ "Could not find the provided dtb !\n");
+ return -EINVAL;
+ }
+ arch_options.fdt_path = optarg;
+ break;
+ case OPT_INITRD:
+ ret = stat(optarg, &st);
+ if (ret) {
+ fprintf(stderr,
+ "Could not find the provided "
+ "initrd image !\n");
+ return -EINVAL;
+ }
+ arch_options.initrd_path = optarg;
+ break;
+ default:
+ break;
+ }
+ }
+
+ /* Handle Kernel's command line */
+ if (append && !cmdline)
+ fprintf(stderr, "Warning: No cmdline provided, "
+ "using append string as cmdline\n");
+ if (!append && !cmdline)
+ fprintf(stderr, "Warning: No cmdline or append string "
+ "provided\n");
+
+ if (append || cmdline)
+ /*
+ * Note that this also handles the case where "cmdline"
+ * or "append" is NULL.
+ */
+ arch_options.cmdline = concat_cmdline(cmdline, append);
+
+ /* Handle FDT image */
+ if (!arch_options.fdt_path) {
+ ret = stat("/sys/firmware/fdt", &st);
+ if (ret) {
+ fprintf(stderr, "No dtb provided and "
+ "/sys/firmware/fdt is not present\n");
+ return -EINVAL;
+ }
+ fprintf(stderr, "Warning: No dtb provided, "
+ "using /sys/firmware/fdt\n");
+ arch_options.fdt_path = "/sys/firmware/fdt";
+ }
+
+ tmp = slurp_file(arch_options.fdt_path, &tmp_size);
+ if (!tmp) {
+ fprintf(stderr, "Couldn't read provided fdt\n");
+ return -EINVAL;
+ }
+
+ ret = fdt_check_header(tmp);
+ if (ret) {
+ fprintf(stderr, "Got an ivalid fdt image !\n");
+ free(tmp);
+ return -EINVAL;
+ }
+ provided_fdt.buf = tmp;
+ provided_fdt.size = tmp_size;
+
+ if (arch_options.cmdline) {
+ ret = dtb_set_bootargs(&provided_fdt.buf, &provided_fdt.size,
+ arch_options.cmdline);
+ if (ret < 0) {
+ fprintf(stderr, "Could not set bootargs on "
+ "the fdt image\n");
+ return ret;
+ }
+ }
+
+ arch_options.fdt = &provided_fdt;
+
+ return 0;
+}
+
+/*
+ * This one is called after arch_process_options so we already
+ * have an fdt image in place.
+ */
+void arch_reuse_initrd(void)
+{
+ const uint32_t *prop32 = NULL;
+ uint32_t addr_cells = 0;
+ const void *prop = 0;
+ int prop_size = 0;
+ uint64_t initrd_start = 0;
+ uint64_t initrd_end = 0;
+ int chosen_offset = 0;
+ struct fdt_image *fdt = &provided_fdt;
+
+ chosen_offset = fdt_subnode_offset(fdt->buf, 0, "chosen");
+ if (chosen_offset < 0) {
+ fprintf(stderr, "No /chosen node found on fdt image "
+ "unable to reuse initrd\n");
+ return;
+ }
+
+ prop32 = fdt_getprop(fdt->buf, 0, "#address-cells", NULL);
+ if (!prop32) {
+ fprintf(stderr, "No #address-cells property on root node\n");
+ return;
+ }
+ addr_cells = be32_to_cpu(*prop32);
+
+ prop = fdt_getprop(fdt->buf, chosen_offset,
+ "linux,initrd-start", &prop_size);
+ if (!prop) {
+ fprintf(stderr, "Could not get linux,initrd-start\n");
+ return;
+ }
+ dtb_extract_int_property(&initrd_start, prop, addr_cells);
+
+ prop = fdt_getprop(fdt->buf, chosen_offset,
+ "linux,initrd-end", &prop_size);
+ if (!prop) {
+ fprintf(stderr, "Could not get linux,initrd-end\n");
+ return;
+ }
+ dtb_extract_int_property(&initrd_end, prop, addr_cells);
+
+ arch_options.initrd_start = initrd_start;
+ arch_options.initrd_end = initrd_end;
+ dbgprintf("initrd_start: 0x%lX, initrd_end: 0x%lX\n",
+ initrd_start, initrd_end);
+
+}
+
+static bool to_be_excluded(char *str, unsigned long long start, unsigned long long end)
+{
+ if (!strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL))) {
+ uint64_t load_start, load_end;
+
+ if (!get_crash_kernel_load_range(&load_start, &load_end) &&
+ (load_start == start) && (load_end == end))
+ return false;
+
+ return true;
+ }
+
+ if (!strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) ||
+ !strncmp(str, KERNEL_CODE, strlen(KERNEL_CODE)) ||
+ !strncmp(str, KERNEL_DATA, strlen(KERNEL_DATA)))
+ return false;
+ else
+ return true;
+}
+
+int get_memory_ranges(struct memory_range **range, int *num_ranges,
+ unsigned long kexec_flags)
+{
+ struct memory_ranges sysmem_ranges = {0};
+ const char *iomem = proc_iomem();
+ struct memory_range excl_range;
+ unsigned long long start, end;
+ int consumed, count, ret = 0;
+ FILE *fp = NULL, *sp = NULL;
+ char line[MAX_LINE], *str;
+
+ fp = fopen(iomem, "r");
+ if (!fp) {
+ fprintf(stderr, "Cannot open %s: %s\n", iomem, strerror(errno));
+ return -1;
+ }
+
+ sp = fopen(iomem, "r");
+ if (!sp) {
+ fprintf(stderr, "Cannot open %s: %s\n", iomem, strerror(errno));
+ ret = -1;
+ goto err;
+ }
+
+ /*
+ * Perform two passes: First add all System RAM, and then
+ * exclude the "Reserved" ranges"
+ */
+ while (fgets(line, sizeof(line), fp) != 0) {
+ count = sscanf(line, "%llx-%llx : %n", &start, &end, &consumed);
+ if (count != 2)
+ continue;
+ str = line + consumed;
+
+ if (!strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM))) {
+ ret = mem_regions_alloc_and_add(&sysmem_ranges,
+ start, end - start + 1, RANGE_RAM);
+ if (ret) {
+ fprintf(stderr,
+ "Cannot allocate memory for ranges\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ }
+ }
+
+ while (fgets(line, sizeof(line), sp) != 0) {
+ count = sscanf(line, "%llx-%llx : %n", &start, &end, &consumed);
+ if (count != 2)
+ continue;
+ str = line + consumed;
+
+ if (to_be_excluded(str, start, end)) {
+ excl_range.start = start;
+ excl_range.end = end;
+
+ ret = mem_regions_alloc_and_exclude(&sysmem_ranges, &excl_range);
+ if (ret) {
+ fprintf(stderr,
+ "Cannot allocate memory for ranges (exclude)\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
+ }
+
+ *range = sysmem_ranges.ranges;
+ *num_ranges = sysmem_ranges.size;
+
+ dbgprint_mem_range("System RAM ranges;",
+ sysmem_ranges.ranges, sysmem_ranges.size);
+
+ ret = 0;
+ err:
+ if (fp)
+ fclose(fp);
+ if (sp)
+ fclose(sp);
+ return ret;
+}
+
+/*******\
+* STUBS *
+\*******/
+
+int arch_compat_trampoline(struct kexec_info *UNUSED(info))
+{
+ return 0;
+}
+
+void arch_update_purgatory(struct kexec_info *UNUSED(info))
+{
+}
+
+int arch_do_exclude_segment(struct kexec_info *UNUSED(info), struct kexec_segment *UNUSED(segment))
+{
+ return 0;
+}
diff --git a/kexec/arch/riscv/kexec-riscv.h b/kexec/arch/riscv/kexec-riscv.h
new file mode 100644
index 000000000000..c4323a65dacf
--- /dev/null
+++ b/kexec/arch/riscv/kexec-riscv.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 FORTH-ICS/CARV
+ * Nick Kossifidis <mick@ics.forth.gr>
+ */
+
+struct fdt_image {
+ char *buf;
+ off_t size;
+};
+
+struct riscv_opts {
+ char *cmdline;
+ char *fdt_path;
+ char *initrd_path;
+ uint64_t initrd_start;
+ uint64_t initrd_end;
+ struct fdt_image *fdt;
+};
+
+/* crashdump-riscv.c */
+extern struct memory_range elfcorehdr_mem;
+int load_elfcorehdr(struct kexec_info *info);
+
+/* kexec-riscv.c */
+int load_extra_segments(struct kexec_info *info, uint64_t kernel_base,
+ uint64_t kernel_size, uint64_t max_addr);
+
+int elf_riscv_probe(const char *buf, off_t len);
+void elf_riscv_usage(void);
+int elf_riscv_load(int argc, char **argv, const char *buf, off_t len,
+ struct kexec_info *info);
diff --git a/kexec/dt-ops.c b/kexec/dt-ops.c
index 0a96b75f65aa..3e285ab2043b 100644
--- a/kexec/dt-ops.c
+++ b/kexec/dt-ops.c
@@ -4,9 +4,11 @@
#include <libfdt.h>
#include <stdio.h>
#include <stdlib.h>
+#include <stdbool.h>

#include "kexec.h"
#include "dt-ops.h"
+#include "mem_regions.h"

static const char n_chosen[] = "chosen";

@@ -95,7 +97,7 @@ int dtb_set_property(char **dtb, off_t *dtb_size, const char *node,

strcpy(new_node, "/");
strcat(new_node, node);
-
+
nodeoffset = fdt_path_offset(new_dtb, new_node);

if (nodeoffset == -FDT_ERR_NOTFOUND) {
@@ -174,3 +176,441 @@ int dtb_delete_property(char *dtb, const char *node, const char *prop)
free(new_node);
return result;
}
+
+static int dtb_get_num_cells(char *dtb, int nodeoffset, uint32_t *addr_cells,
+ uint32_t *size_cells, bool recursive)
+{
+ const uint32_t *prop32 = NULL;
+ int curr_offset = nodeoffset;
+ int prop_len = 0;
+ *addr_cells = 0;
+ *size_cells = 0;
+
+ do {
+ prop32 = fdt_getprop(dtb, curr_offset, "#address-cells", &prop_len);
+ curr_offset = fdt_parent_offset(dtb, curr_offset);
+ } while (!prop32 && prop_len == -FDT_ERR_NOTFOUND && recursive);
+
+ if (!prop32) {
+ dbgprintf("Could not get #address-cells property for %s (%s)\n",
+ fdt_get_name(dtb, nodeoffset, NULL), fdt_strerror(nodeoffset));
+ return -EINVAL;
+ }
+ *addr_cells = fdt32_to_cpu(*prop32);
+
+ curr_offset = nodeoffset;
+ do {
+ prop32 = fdt_getprop(dtb, curr_offset, "#size-cells", &prop_len);
+ curr_offset = fdt_parent_offset(dtb, curr_offset);
+ } while (!prop32 && prop_len == -FDT_ERR_NOTFOUND && recursive);
+
+ if (!prop32) {
+ dbgprintf("Could not get #size-cells property for %s (%s)\n",
+ fdt_get_name(dtb, nodeoffset, NULL), fdt_strerror(nodeoffset));
+ return -EINVAL;
+ }
+ *size_cells = fdt32_to_cpu(*prop32);
+
+ dbgprintf("%s: #address-cells:%d #size-cells:%d\n",
+ fdt_get_name(dtb, nodeoffset, NULL), *addr_cells, *size_cells);
+
+ return 0;
+}
+
+void dtb_extract_int_property(uint64_t *val, const void *buf, uint32_t cells)
+{
+ const uint32_t *prop32 = NULL;
+ const uint64_t *prop64 = NULL;
+
+ if (cells == 1) {
+ prop32 = (const uint32_t *) buf;
+ *val = (uint64_t) be32_to_cpu(*prop32);
+ } else {
+ /* Skip any leading cells */
+ prop64 = (const uint64_t *) (uint32_t *)buf + cells - 2;
+ *val = (uint64_t) be64_to_cpu(*prop64);
+ }
+}
+
+void dtb_fill_int_property(void *buf, uint64_t val, uint32_t cells)
+{
+ uint32_t prop32 = 0;
+ uint64_t prop64 = 0;
+
+ if (cells == 1) {
+ prop32 = cpu_to_fdt32((uint32_t) val);
+ memcpy(buf, &prop32, sizeof(uint32_t));
+ } else {
+ prop64 = cpu_to_fdt64(val);
+ /* Skip any leading cells */
+ memcpy((uint64_t *)(uint32_t *)buf + cells - 2,
+ &prop64, sizeof(uint64_t));
+ }
+}
+
+int dtb_add_range_property(char **dtb, off_t *dtb_size, uint64_t start, uint64_t end,
+ const char *parent, const char *name)
+{
+ uint32_t addr_cells = 0;
+ uint32_t size_cells = 0;
+ char *nodepath = NULL;
+ void *prop = NULL;
+ int nodeoffset = 0;
+ int prop_size = 0;
+ int ret = 0;
+
+ nodepath = malloc(strlen("/") + strlen(parent) + 1);
+ if (!nodepath) {
+ dbgprintf("%s: malloc failed\n", __func__);
+ return -ENOMEM;
+ }
+
+ strcpy(nodepath, "/");
+ strcat(nodepath, parent);
+
+ nodeoffset = fdt_path_offset(*dtb, nodepath);
+ if (nodeoffset < 0) {
+ dbgprintf("%s: fdt_path_offset(%s) failed: %s\n", __func__,
+ nodepath, fdt_strerror(nodeoffset));
+ free(nodepath);
+ return nodeoffset;
+ }
+ free(nodepath);
+
+ ret = dtb_get_num_cells(*dtb, nodeoffset, &addr_cells, &size_cells, true);
+ if (ret < 0)
+ return ret;
+
+ /* Can the range fit with the given address/size cells ? */
+ if ((addr_cells == 1) && (start >= (1ULL << 32)))
+ return -EINVAL;
+
+ if ((size_cells == 1) && ((end - start + 1) >= (1ULL << 32)))
+ return -EINVAL;
+
+ prop_size = sizeof(uint32_t) * (addr_cells + size_cells);
+ prop = malloc(prop_size);
+
+ dtb_fill_int_property(prop, start, addr_cells);
+ dtb_fill_int_property((void *)((uint32_t *)prop + addr_cells),
+ end - start + 1, size_cells);
+
+ /* Add by node path name */
+ return dtb_set_property(dtb, dtb_size, parent, name, prop, prop_size);
+}
+
+/************************\
+* MEMORY RANGES HANDLING *
+\************************/
+
+static int dtb_add_memory_range(struct memory_ranges *mem_ranges, uint64_t start,
+ uint64_t end, unsigned type)
+{
+ struct memory_range this_region = {0};
+ struct memory_range *ranges = mem_ranges->ranges;
+ int i = 0;
+ int ret = 0;
+
+ if (start == end) {
+ dbgprintf("Ignoring empty region\n");
+ return -EINVAL;
+ }
+
+ /* Check if we are adding an existing region */
+ for (i = 0; i < mem_ranges->size; i++) {
+ if (start == ranges[i].start && end == ranges[i].end) {
+ dbgprintf("Duplicate: 0x%lx - 0x%lx\n", start, end);
+
+ if (type == ranges[i].type)
+ return 0;
+ else if (type == RANGE_RESERVED) {
+ ranges[i].type = RANGE_RESERVED;
+ return 0;
+ }
+
+ dbgprintf("Conflicting types for region: 0x%lx - 0x%lx\n",
+ start, end);
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * Reserved regions may be part of an existing /memory
+ * region and shouldn't overlap according to spec, so
+ * since we add /memory regions first, we can exclude
+ * reserved regions here from the existing /memory regions
+ * included in ranges[], so that we don't have the same
+ * region twice.
+ */
+ if (type == RANGE_RESERVED) {
+ this_region.start = start;
+ this_region.end = end - 1;
+ this_region.type = type;
+ ret = mem_regions_exclude(mem_ranges, &this_region);
+ if (ret)
+ return ret;
+ }
+
+ ret = mem_regions_alloc_and_add(mem_ranges, start,
+ end - start, type);
+
+ return ret;
+}
+
+static int dtb_add_memory_region(char *dtb, int nodeoffset,
+ struct memory_ranges *mem_ranges, int type)
+{
+ uint32_t root_addr_cells = 0;
+ uint32_t root_size_cells = 0;
+ uint64_t addr = 0;
+ uint64_t size = 0;
+ const char *reg = NULL;
+ int prop_size = 0;
+ int offset = 0;
+ int entry_size = 0;
+ int num_entries = 0;
+ int ret = 0;
+
+ /*
+ * Get address-cells and size-cells properties (according to
+ * binding spec these are the same as in the root node)
+ */
+ ret = dtb_get_num_cells(dtb, 0, &root_addr_cells, &root_size_cells, false);
+ if (ret < 0) {
+ dbgprintf("No address/size cells on root node !\n");
+ return ret;
+ }
+
+ /*
+ * Parse the reg array, acording to device tree spec it includes
+ * an arbitary number of <size> pairs
+ */
+ entry_size = (root_addr_cells + root_size_cells) * sizeof(uint32_t);
+ reg = fdt_getprop(dtb, nodeoffset, "reg", &prop_size);
+ if (!reg) {
+ dbgprintf("Warning: Malformed memory region with no reg property (%s) !\n",
+ fdt_get_name(dtb, nodeoffset, NULL));
+ return -EINVAL;
+ }
+
+ num_entries = prop_size / entry_size;
+ dbgprintf("Got region with %i entries: %s\n", num_entries,
+ fdt_get_name(dtb, nodeoffset, NULL));
+
+ for (num_entries--; num_entries >= 0; num_entries--) {
+ offset = num_entries * entry_size;
+
+ dtb_extract_int_property(&addr, reg + offset,
+ root_addr_cells);
+ offset += root_addr_cells * sizeof(uint32_t);
+
+ dtb_extract_int_property(&size, reg + offset,
+ root_size_cells);
+
+ ret = dtb_add_memory_range(mem_ranges, addr,
+ addr + size, type);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int dtb_parse_memory_reservations_table(char *dtb, struct memory_ranges *mem_ranges)
+{
+ int total_memrsrv = 0;
+ uint64_t addr = 0;
+ uint64_t size = 0;
+ int ret = 0;
+ int i = 0;
+
+ total_memrsrv = fdt_num_mem_rsv(dtb);
+ for (i = 0; i < total_memrsrv; i++) {
+ ret = fdt_get_mem_rsv(dtb, i, &addr, &size);
+ if (ret)
+ continue;
+ ret = dtb_add_memory_range(mem_ranges, addr, addr + size - 1,
+ RANGE_RESERVED);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int dtb_get_reserved_memory_node(char *dtb)
+{
+ uint32_t root_addr_cells = 0;
+ uint32_t root_size_cells = 0;
+ uint32_t addr_cells = 0;
+ uint32_t size_cells = 0;
+ int prop_size = 0;
+ int nodeoffset = 0;
+ int ret = 0;
+
+ /* Get address / size cells from root node */
+ ret = dtb_get_num_cells(dtb, 0, &root_addr_cells, &root_size_cells, false);
+ if (ret < 0) {
+ dbgprintf("No address/size cells on root node !\n");
+ return ret;
+ }
+
+ /* This calls fdt_next_node internaly */
+ nodeoffset = fdt_subnode_offset(dtb, 0, "reserved-memory");
+ if (nodeoffset == -FDT_ERR_NOTFOUND) {
+ return nodeoffset;
+ } else if (nodeoffset < 0) {
+ dbgprintf("Error while looking for reserved-memory: %s\n",
+ fdt_strerror(nodeoffset));
+ return nodeoffset;
+ }
+
+ /* Look for the ranges property */
+ fdt_getprop(dtb, nodeoffset, "ranges", &prop_size);
+ if (prop_size < 0) {
+ fprintf(stderr, "Malformed reserved-memory node (no ranges property) !\n");
+ return -EINVAL;
+ }
+
+ /* Verify address-cells / size-cells */
+ ret = dtb_get_num_cells(dtb, nodeoffset, &addr_cells, &size_cells, false);
+ if (ret < 0) {
+ dbgprintf("No address/size cells property on reserved-memory node\n");
+ return ret;
+ }
+
+ if (addr_cells != root_addr_cells) {
+ fprintf(stderr, "Invalid #address-cells property on reserved-memory node\n");
+ return -EINVAL;
+ }
+
+ if (size_cells != root_size_cells) {
+ fprintf(stderr, "Invalid #size-cells property on reserved-memory node\n");
+ return -EINVAL;
+
+ }
+
+ return nodeoffset;
+}
+
+static int dtb_parse_reserved_memory_node(char *dtb, struct memory_ranges *mem_ranges)
+{
+ int nodeoffset = 0;
+ int node_depth = 0;
+ int parent_depth = 0;
+ int ret = 0;
+
+ nodeoffset = dtb_get_reserved_memory_node(dtb);
+ if (nodeoffset == -FDT_ERR_NOTFOUND)
+ return 0;
+ else if (nodeoffset < 0)
+ return nodeoffset;
+
+ /* Got the parent node, check for sub-nodes */
+
+ /* fdt_next_node() increases or decreases depth */
+ node_depth = parent_depth;
+ nodeoffset = fdt_next_node(dtb, nodeoffset, &node_depth);
+ if (ret < 0) {
+ dbgprintf("Unable to get next node: %s\n",
+ fdt_strerror(ret));
+ return -EINVAL;
+ }
+
+ while (node_depth != parent_depth) {
+
+ ret = dtb_add_memory_region(dtb, nodeoffset,
+ mem_ranges, RANGE_RESERVED);
+ if (ret)
+ return ret;
+
+ nodeoffset = fdt_next_node(dtb, nodeoffset, &node_depth);
+ if (ret < 0) {
+ dbgprintf("Unable to get next node: %s\n",
+ fdt_strerror(ret));
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int dtb_parse_memory_nodes(char *dtb, struct memory_ranges *mem_ranges)
+{
+ int nodeoffset = 0;
+ int num_regions = 0;
+ const char* dev_type = 0;
+ int prop_size = 0;
+ int ret = 0;
+
+ for (; ; num_regions++) {
+ nodeoffset = fdt_subnode_offset(dtb, nodeoffset,
+ "memory");
+ if (nodeoffset < 0)
+ break;
+
+ dbgprintf("Got memory node at depth: %i\n", fdt_node_depth(dtb, nodeoffset));
+
+ /* Look for the device_type property */
+ dev_type = fdt_getprop(dtb, nodeoffset, "device_type", &prop_size);
+ if (prop_size < 0) {
+ fprintf(stderr, "Malformed /memory node (no device-type property) !\n");
+ return -EINVAL;
+ }
+
+ if (strncmp(dev_type, "memory", prop_size)) {
+ dbgprintf("Got unknown dev_type property: %s\n", dev_type);
+ continue;
+ }
+
+ ret = dtb_add_memory_region(dtb, nodeoffset, mem_ranges, RANGE_RAM);
+ if (ret)
+ return ret;
+ }
+
+ if (!num_regions) {
+ dbgprintf("Malformed dtb, no /memory nodes present !\n");
+ return -EINVAL;
+ }
+
+ dbgprintf("Got %i /memory nodes\n", num_regions);
+
+ return 0;
+}
+
+int dtb_get_memory_ranges(char *dtb, struct memory_ranges *mem_ranges, struct memory_ranges *extra_ranges)
+{
+ int i = 0;
+ int ret = 0;
+
+ /* Fill mem_ranges[] by parsing the device tree */
+ ret = dtb_parse_memory_nodes(dtb, mem_ranges);
+ if (ret)
+ return ret;
+
+ ret = dtb_parse_memory_reservations_table(dtb, mem_ranges);
+ if (ret)
+ return ret;
+
+ ret = dtb_parse_reserved_memory_node(dtb, mem_ranges);
+ if (ret)
+ return ret;
+
+ /* Append any extra ranges provided by the caller (e.g. initrd) */
+ for (i = 0; extra_ranges != NULL && i < extra_ranges->size; i++) {
+ dbgprintf("Adding extra range: 0x%llx - 0x%llx (%s)\n",
+ extra_ranges->ranges[i].start,
+ extra_ranges->ranges[i].end,
+ extra_ranges->ranges[i].type == RANGE_RESERVED ?
+ "RANGE_RESERVED" : "RANGE_RAM");
+
+ ret = dtb_add_memory_range(mem_ranges, extra_ranges->ranges[i].start,
+ extra_ranges->ranges[i].end, extra_ranges->ranges[i].type);
+ if (ret)
+ return ret;
+ }
+
+ mem_regions_sort(mem_ranges);
+
+ return 0;
+}
diff --git a/kexec/dt-ops.h b/kexec/dt-ops.h
index 03659ce283db..3014205d8e98 100644
--- a/kexec/dt-ops.h
+++ b/kexec/dt-ops.h
@@ -11,4 +11,11 @@ int dtb_set_property(char **dtb, off_t *dtb_size, const char *node,

int dtb_delete_property(char *dtb, const char *node, const char *prop);

+void dtb_extract_int_property(uint64_t *val, const void *buf, uint32_t cells);
+void dtb_fill_int_property(void *buf, uint64_t val, uint32_t cells);
+int dtb_add_range_property(char **dtb, off_t *dtb_size, uint64_t start, uint64_t end,
+ const char *node, const char* parent);
+int dtb_get_memory_ranges(char *dtb, struct memory_ranges *mem_ranges,
+ struct memory_ranges *extra_ranges);
+
#endif
diff --git a/kexec/kexec-syscall.h b/kexec/kexec-syscall.h
index cc32c0162aec..89591ad17e7d 100644
--- a/kexec/kexec-syscall.h
+++ b/kexec/kexec-syscall.h
@@ -140,6 +140,7 @@ static inline long kexec_file_load(int kernel_fd, int initrd_fd,
#define KEXEC_ARCH_MIPS_LE (10 << 16)
#define KEXEC_ARCH_MIPS ( 8 << 16)
#define KEXEC_ARCH_CRIS (76 << 16)
+#define KEXEC_ARCH_RISCV (243 << 16)
#define KEXEC_ARCH_LOONGARCH (258 << 16)

#define KEXEC_MAX_SEGMENTS 16
@@ -187,5 +188,8 @@ static inline long kexec_file_load(int kernel_fd, int initrd_fd,
#if defined(__loongarch__)
#define KEXEC_ARCH_NATIVE KEXEC_ARCH_LOONGARCH
#endif
+#if defined(__riscv__) || defined(__riscv)
+#define KEXEC_ARCH_NATIVE KEXEC_ARCH_RISCV
+#endif

#endif /* KEXEC_SYSCALL_H */
diff --git a/purgatory/Makefile b/purgatory/Makefile
index 4d2d07134bd5..7d1175f2445c 100644
--- a/purgatory/Makefile
+++ b/purgatory/Makefile
@@ -25,6 +25,7 @@ include $(srcdir)/purgatory/arch/ia64/Makefile
include $(srcdir)/purgatory/arch/mips/Makefile
include $(srcdir)/purgatory/arch/ppc/Makefile
include $(srcdir)/purgatory/arch/ppc64/Makefile
+include $(srcdir)/purgatory/arch/riscv/Makefile
include $(srcdir)/purgatory/arch/s390/Makefile
include $(srcdir)/purgatory/arch/sh/Makefile
include $(srcdir)/purgatory/arch/x86_64/Makefile
diff --git a/purgatory/arch/riscv/Makefile b/purgatory/arch/riscv/Makefile
new file mode 100644
index 000000000000..49a6fef4a904
--- /dev/null
+++ b/purgatory/arch/riscv/Makefile
@@ -0,0 +1,7 @@
+#
+# Purgatory riscv
+#
+
+riscv_PURGATORY_SRCS =
+
+dist += purgatory/arch/riscv/Makefile $(riscv_PURGATORY_SRCS)