Re: [PATCH v3 2/2] remoteproc: Add elf64 support in elf loader

From: Mathieu Poirier
Date: Thu Feb 06 2020 - 12:48:39 EST

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On Thu, Feb 06, 2020 at 04:05:44PM +0100, Clément Leger wrote:
> Hi Mathieu,
>
> ----- On 6 Feb, 2020, at 09:37, Clément Leger cleger@xxxxxxxxx wrote:
>
> > Hi Mathieu,
> >
> > ----- On 5 Feb, 2020, at 23:49, Mathieu Poirier mathieu.poirier@xxxxxxxxxx
> > wrote:
> >
> >> On Tue, Feb 04, 2020 at 06:44:12PM +0100, Clement Leger wrote:
> >>> elf32 and elf64 mainly differ by their types. In order to avoid
> >>> copy/pasting the whole loader code, generate static inline functions
> >>> which will access values according to the elf class. It allows to keep a
> >>> common loader basis.
> >>> In order to accommodate both elf types sizes, the maximum size for a
> >>> elf header member is chosen using the maximum value of both elf class.
> >>>
> >>> Signed-off-by: Clement Leger <cleger@xxxxxxxxx>
> >>> Tested-by: Arnaud POULIQUEN <arnaud.pouliquen@xxxxxx>
> >>> ---
> >>> Documentation/remoteproc.txt | 2 +-
> >>> drivers/remoteproc/remoteproc_elf_loader.c | 147 ++++++++++++++++++-----------
> >>> drivers/remoteproc/remoteproc_elf_loader.h | 69 ++++++++++++++
> >>> drivers/remoteproc/remoteproc_internal.h | 2 +-
> >>> drivers/remoteproc/st_remoteproc.c | 2 +-
> >>> include/linux/remoteproc.h | 4 +-
> >>> 6 files changed, 167 insertions(+), 59 deletions(-)
> >>> create mode 100644 drivers/remoteproc/remoteproc_elf_loader.h
> >>>
> >>> diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt
> >>> index 03c3d2e568b0..2be1147256e0 100644
> >>> --- a/Documentation/remoteproc.txt
> >>> +++ b/Documentation/remoteproc.txt
> >>> @@ -230,7 +230,7 @@ in the used rings.
> >>> Binary Firmware Structure
> >>> =========================
> >>>
> >>> -At this point remoteproc only supports ELF32 firmware binaries. However,
> >>> +At this point remoteproc supports ELF32 and ELF64 firmware binaries. However,
> >>> it is quite expected that other platforms/devices which we'd want to
> >>> support with this framework will be based on different binary formats.
> >>>
> >>> diff --git a/drivers/remoteproc/remoteproc_elf_loader.c
> >>> b/drivers/remoteproc/remoteproc_elf_loader.c
> >>> index 606aae166eba..21fd2b2fe5ae 100644
> >>> --- a/drivers/remoteproc/remoteproc_elf_loader.c
> >>> +++ b/drivers/remoteproc/remoteproc_elf_loader.c
> >>> @@ -23,6 +23,7 @@
> >>> #include <linux/elf.h>
> >>>
> >>> #include "remoteproc_internal.h"
> >>> +#include "remoteproc_elf_loader.h"
> >>>
> >>> /**
> >>> * rproc_elf_sanity_check() - Sanity Check ELF firmware image
> >>> @@ -35,8 +36,16 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct
> >>> firmware *fw)
> >>> {
> >>> const char *name = rproc->firmware;
> >>> struct device *dev = &rproc->dev;
> >>> + /*
> >>> + * Elf files are beginning with the same structure. Thus, to simplify
> >>> + * header parsing, we can use the elf32_hdr one for both elf64 and
> >>> + * elf32.
> >>> + */
> >>> struct elf32_hdr *ehdr;
> >>> + u32 elf_shdr_size;
> >>> + u64 phoff, shoff;
> >>> char class;
> >>> + u16 phnum;
> >>>
> >>> if (!fw) {
> >>> dev_err(dev, "failed to load %s\n", name);
> >>> @@ -50,13 +59,22 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct
> >>> firmware *fw)
> >>>
> >>> ehdr = (struct elf32_hdr *)fw->data;
> >>>
> >>> - /* We only support ELF32 at this point */
> >>> + if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
> >>> + dev_err(dev, "Image is corrupted (bad magic)\n");
> >>> + return -EINVAL;
> >>> + }
> >>> +
> >>> class = ehdr->e_ident[EI_CLASS];
> >>> - if (class != ELFCLASS32) {
> >>> + if (class != ELFCLASS32 && class != ELFCLASS64) {
> >>> dev_err(dev, "Unsupported class: %d\n", class);
> >>> return -EINVAL;
> >>> }
> >>>
> >>> + if (class == ELFCLASS64 && fw->size < sizeof(struct elf64_hdr)) {
> >>> + dev_err(dev, "elf64 header is too small\n");
> >>> + return -EINVAL;
> >>> + }
> >>> +
> >>> /* We assume the firmware has the same endianness as the host */
> >>> # ifdef __LITTLE_ENDIAN
> >>> if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
> >>> @@ -67,26 +85,29 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct
> >>> firmware *fw)
> >>> return -EINVAL;
> >>> }
> >>>
> >>> - if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
> >>> - dev_err(dev, "Image is too small\n");
> >>> - return -EINVAL;
> >>> - }
> >>> + phoff = elf_hdr_e_phoff(class, fw->data);
> >>> + shoff = elf_hdr_e_shoff(class, fw->data);
> >>> + phnum = elf_hdr_e_phnum(class, fw->data);
> >>> + elf_shdr_size = elf_size_of_shdr(class);
> >>>
> >>> - if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
> >>> - dev_err(dev, "Image is corrupted (bad magic)\n");
> >>> + if (fw->size < shoff + elf_shdr_size) {
> >>> + dev_err(dev, "Image is too small\n");
> >>> return -EINVAL;
> >>> }
> >>>
> >>> - if (ehdr->e_phnum == 0) {
> >>> + if (phnum == 0) {
> >>> dev_err(dev, "No loadable segments\n");
> >>> return -EINVAL;
> >>> }
> >>>
> >>> - if (ehdr->e_phoff > fw->size) {
> >>> + if (phoff > fw->size) {
> >>> dev_err(dev, "Firmware size is too small\n");
> >>> return -EINVAL;
> >>> }
> >>>
> >>> + dev_dbg(dev, "Firmware is an elf%d file\n",
> >>> + class == ELFCLASS32 ? 32 : 64);
> >>> +
> >>> return 0;
> >>> }
> >>> EXPORT_SYMBOL(rproc_elf_sanity_check);
> >>> @@ -102,11 +123,9 @@ EXPORT_SYMBOL(rproc_elf_sanity_check);
> >>> * Note that the boot address is not a configurable property of all remote
> >>> * processors. Some will always boot at a specific hard-coded address.
> >>> */
> >>> -u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
> >>> +u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
> >>> {
> >>> - struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
> >>> -
> >>> - return ehdr->e_entry;
> >>> + return elf_hdr_e_entry(fw_elf_get_class(fw), fw->data);
> >>> }
> >>> EXPORT_SYMBOL(rproc_elf_get_boot_addr);
> >>>
> >>> @@ -137,37 +156,41 @@ EXPORT_SYMBOL(rproc_elf_get_boot_addr);
> >>> int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
> >>> {
> >>> struct device *dev = &rproc->dev;
> >>> - struct elf32_hdr *ehdr;
> >>> - struct elf32_phdr *phdr;
> >>> + const void *ehdr, *phdr;
> >>> int i, ret = 0;
> >>> + u16 phnum;
> >>> const u8 *elf_data = fw->data;
> >>> + u8 class = fw_elf_get_class(fw);
> >>> + u32 elf_phdr_size = elf_size_of_phdr(class);
> >>>
> >>> - ehdr = (struct elf32_hdr *)elf_data;
> >>> - phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
> >>> + ehdr = elf_data;
> >>> + phnum = elf_hdr_e_phnum(class, ehdr);
> >>> + phdr = elf_data + elf_hdr_e_phoff(class, ehdr);
> >>>
> >>> /* go through the available ELF segments */
> >>> - for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
> >>> - u32 da = phdr->p_paddr;
> >>> - u32 memsz = phdr->p_memsz;
> >>> - u32 filesz = phdr->p_filesz;
> >>> - u32 offset = phdr->p_offset;
> >>> + for (i = 0; i < phnum; i++, phdr += elf_phdr_size) {
> >>> + u64 da = elf_phdr_p_paddr(class, phdr);
> >>> + u64 memsz = elf_phdr_p_memsz(class, phdr);
> >>> + u64 filesz = elf_phdr_p_filesz(class, phdr);
> >>> + u64 offset = elf_phdr_p_offset(class, phdr);
> >>> + u32 type = elf_phdr_p_type(class, phdr);
> >>> void *ptr;
> >>>
> >>> - if (phdr->p_type != PT_LOAD)
> >>> + if (type != PT_LOAD)
> >>> continue;
> >>>
> >>> - dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
> >>> - phdr->p_type, da, memsz, filesz);
> >>> + dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
> >>> + type, da, memsz, filesz);
> >>>
> >>> if (filesz > memsz) {
> >>> - dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
> >>> + dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
> >>> filesz, memsz);
> >>> ret = -EINVAL;
> >>> break;
> >>> }
> >>>
> >>> if (offset + filesz > fw->size) {
> >>> - dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
> >>> + dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
> >>> offset + filesz, fw->size);
> >>> ret = -EINVAL;
> >>> break;
> >>> @@ -176,14 +199,15 @@ int rproc_elf_load_segments(struct rproc *rproc, const
> >>> struct firmware *fw)
> >>> /* grab the kernel address for this device address */
> >>> ptr = rproc_da_to_va(rproc, da, memsz);
> >>> if (!ptr) {
> >>> - dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
> >>> + dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
> >>> + memsz);
> >>> ret = -EINVAL;
> >>> break;
> >>> }
> >>>
> >>> /* put the segment where the remote processor expects it */
> >>> - if (phdr->p_filesz)
> >>> - memcpy(ptr, elf_data + phdr->p_offset, filesz);
> >>> + if (filesz)
> >>> + memcpy(ptr, elf_data + offset, filesz);
> >>>
> >>> /*
> >>> * Zero out remaining memory for this segment.
> >>> @@ -200,24 +224,35 @@ int rproc_elf_load_segments(struct rproc *rproc, const
> >>> struct firmware *fw)
> >>> }
> >>> EXPORT_SYMBOL(rproc_elf_load_segments);
> >>>
> >>> -static struct elf32_shdr *
> >>> -find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
> >>> +static const void *
> >>> +find_table(struct device *dev, const struct firmware *fw)
> >>> {
> >>> - struct elf32_shdr *shdr;
> >>> + const void *shdr, *name_table_shdr;
> >>> int i;
> >>> const char *name_table;
> >>> struct resource_table *table = NULL;
> >>> - const u8 *elf_data = (void *)ehdr;
> >>> + const u8 *elf_data = (void *)fw->data;
> >>> + u8 class = fw_elf_get_class(fw);
> >>> + size_t fw_size = fw->size;
> >>> + const void *ehdr = elf_data;
> >>> + u16 shnum = elf_hdr_e_shnum(class, ehdr);
> >>> + u32 elf_shdr_size = elf_size_of_shdr(class);
> >>> + u16 shstrndx = elf_hdr_e_shstrndx(class, ehdr);
> >>>
> >>> /* look for the resource table and handle it */
> >>> - shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
> >>> - name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset;
> >>> -
> >>> - for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
> >>> - u32 size = shdr->sh_size;
> >>> - u32 offset = shdr->sh_offset;
> >>> -
> >>> - if (strcmp(name_table + shdr->sh_name, ".resource_table"))
> >>> + /* First, get the section header according to the elf class */
> >>> + shdr = elf_data + elf_hdr_e_shoff(class, ehdr);
> >>> + /* Compute name table section header entry in shdr array */
> >>> + name_table_shdr = shdr + (shstrndx * elf_shdr_size);
> >>> + /* Finally, compute the name table section address in elf */
> >>> + name_table = elf_data + elf_shdr_sh_offset(class, name_table_shdr);
> >>> +
> >>> + for (i = 0; i < shnum; i++, shdr += elf_shdr_size) {
> >>> + u64 size = elf_shdr_sh_size(class, shdr);
> >>> + u64 offset = elf_shdr_sh_offset(class, shdr);
> >>> + u32 name = elf_shdr_sh_name(class, shdr);
> >>> +
> >>> + if (strcmp(name_table + name, ".resource_table"))
> >>> continue;
> >>>
> >>> table = (struct resource_table *)(elf_data + offset);
> >>> @@ -270,21 +305,21 @@ find_table(struct device *dev, struct elf32_hdr *ehdr,
> >>> size_t fw_size)
> >>> */
> >>> int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
> >>> {
> >>> - struct elf32_hdr *ehdr;
> >>> - struct elf32_shdr *shdr;
> >>> + const void *shdr;
> >>> struct device *dev = &rproc->dev;
> >>> struct resource_table *table = NULL;
> >>> const u8 *elf_data = fw->data;
> >>> size_t tablesz;
> >>> + u8 class = fw_elf_get_class(fw);
> >>> + u64 sh_offset;
> >>>
> >>> - ehdr = (struct elf32_hdr *)elf_data;
> >>> -
> >>> - shdr = find_table(dev, ehdr, fw->size);
> >>> + shdr = find_table(dev, fw);
> >>> if (!shdr)
> >>> return -EINVAL;
> >>>
> >>> - table = (struct resource_table *)(elf_data + shdr->sh_offset);
> >>> - tablesz = shdr->sh_size;
> >>> + sh_offset = elf_shdr_sh_offset(class, shdr);
> >>> + table = (struct resource_table *)(elf_data + sh_offset);
> >>> + tablesz = elf_shdr_sh_size(class, shdr);
> >>>
> >>> /*
> >>> * Create a copy of the resource table. When a virtio device starts
> >>> @@ -317,13 +352,17 @@ EXPORT_SYMBOL(rproc_elf_load_rsc_table);
> >>> struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
> >>> const struct firmware *fw)
> >>> {
> >>> - struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
> >>> - struct elf32_shdr *shdr;
> >>> + const void *shdr;
> >>> + u64 sh_addr, sh_size;
> >>> + u8 class = fw_elf_get_class(fw);
> >>>
> >>> - shdr = find_table(&rproc->dev, ehdr, fw->size);
> >>> + shdr = find_table(&rproc->dev, fw);
> >>> if (!shdr)
> >>> return NULL;
> >>>
> >>> - return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
> >>> + sh_addr = elf_shdr_sh_addr(class, shdr);
> >>> + sh_size = elf_shdr_sh_size(class, shdr);
> >>> +
> >>> + return rproc_da_to_va(rproc, sh_addr, sh_size);
> >>> }
> >>> EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
> >>> diff --git a/drivers/remoteproc/remoteproc_elf_loader.h
> >>> b/drivers/remoteproc/remoteproc_elf_loader.h
> >>> new file mode 100644
> >>> index 000000000000..fac3565734f9
> >>> --- /dev/null
> >>> +++ b/drivers/remoteproc/remoteproc_elf_loader.h
> >>> @@ -0,0 +1,69 @@
> >>> +/* SPDX-License-Identifier: GPL-2.0 */
> >>> +/*
> >>> + * Remote processor elf loader defines
> >>> + *
> >>> + * Copyright (C) 2019 Kalray, Inc.
> >>> + */
> >>> +
> >>> +#ifndef REMOTEPROC_ELF_LOADER_H
> >>> +#define REMOTEPROC_ELF_LOADER_H
> >>> +
> >>> +#include <linux/elf.h>
> >>> +#include <linux/types.h>
> >>> +
> >>> +/**
> >>> + * fw_elf_get_class - Get elf class
> >>> + * @fw: the ELF firmware image
> >>> + *
> >>> + * Note that we use and elf32_hdr to access the class since the start of the
> >>> + * struct is the same for both elf class
> >>> + *
> >>> + * Return: elf class of the firmware
> >>> + */
> >>> +static inline u8 fw_elf_get_class(const struct firmware *fw)
> >>> +{
> >>> + struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
> >>> +
> >>> + return ehdr->e_ident[EI_CLASS];
> >>> +}
> >>> +
> >>> +#define ELF_GET_FIELD(__s, __field, __type) \
> >>> +static inline __type elf_##__s##_##__field(u8 class, const void *arg) \
> >>> +{ \
> >>> + if (class == ELFCLASS32) \
> >>> + return (__type) ((const struct elf32_##__s *) arg)->__field; \
> >>> + else \
> >>> + return (__type) ((const struct elf64_##__s *) arg)->__field; \
> >>> +}
> >>> +
> >>> +ELF_GET_FIELD(hdr, e_entry, u64)
> >>> +ELF_GET_FIELD(hdr, e_phnum, u16)
> >>> +ELF_GET_FIELD(hdr, e_shnum, u16)
> >>> +ELF_GET_FIELD(hdr, e_phoff, u64)
> >>> +ELF_GET_FIELD(hdr, e_shoff, u64)
> >>> +ELF_GET_FIELD(hdr, e_shstrndx, u16)
> >>> +
> >>> +ELF_GET_FIELD(phdr, p_paddr, u64)
> >>> +ELF_GET_FIELD(phdr, p_filesz, u64)
> >>> +ELF_GET_FIELD(phdr, p_memsz, u64)
> >>> +ELF_GET_FIELD(phdr, p_type, u32)
> >>> +ELF_GET_FIELD(phdr, p_offset, u64)
> >>> +
> >>> +ELF_GET_FIELD(shdr, sh_size, u64)
> >>> +ELF_GET_FIELD(shdr, sh_offset, u64)
> >>> +ELF_GET_FIELD(shdr, sh_name, u32)
> >>> +ELF_GET_FIELD(shdr, sh_addr, u64)
> >>> +
> >>> +#define ELF_STRUCT_SIZE(__s) \
> >>> +static inline unsigned long elf_size_of_##__s(u8 class) \
> >>> +{ \
> >>> + if (class == ELFCLASS32)\
> >>> + return sizeof(struct elf32_##__s); \
> >>> + else \
> >>> + return sizeof(struct elf64_##__s); \
> >>> +}
> >>> +
> >>> +ELF_STRUCT_SIZE(shdr)
> >>> +ELF_STRUCT_SIZE(phdr)
> >>> +
> >>> +#endif /* REMOTEPROC_ELF_LOADER_H */
> >>> diff --git a/drivers/remoteproc/remoteproc_internal.h
> >>> b/drivers/remoteproc/remoteproc_internal.h
> >>> index 004867061721..eeb26434220e 100644
> >>> --- a/drivers/remoteproc/remoteproc_internal.h
> >>> +++ b/drivers/remoteproc/remoteproc_internal.h
> >>> @@ -55,7 +55,7 @@ phys_addr_t rproc_va_to_pa(void *cpu_addr);
> >>> int rproc_trigger_recovery(struct rproc *rproc);
> >>>
> >>> int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw);
> >>> -u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw);
> >>> +u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw);
> >>> int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw);
> >>> int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw);
> >>> struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
> >>> diff --git a/drivers/remoteproc/st_remoteproc.c
> >>> b/drivers/remoteproc/st_remoteproc.c
> >>> index ee13d23b43a9..a3268d95a50e 100644
> >>> --- a/drivers/remoteproc/st_remoteproc.c
> >>> +++ b/drivers/remoteproc/st_remoteproc.c
> >>> @@ -190,7 +190,7 @@ static int st_rproc_start(struct rproc *rproc)
> >>> }
> >>> }
> >>>
> >>> - dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
> >>> + dev_info(&rproc->dev, "Started from 0x%llx\n", rproc->bootaddr);
> >>>
> >>> return 0;
> >>>
> >>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> >>> index f84bd5fe0211..82cebca9344c 100644
> >>> --- a/include/linux/remoteproc.h
> >>> +++ b/include/linux/remoteproc.h
> >>> @@ -382,7 +382,7 @@ struct rproc_ops {
> >>> struct rproc *rproc, const struct firmware *fw);
> >>> int (*load)(struct rproc *rproc, const struct firmware *fw);
> >>> int (*sanity_check)(struct rproc *rproc, const struct firmware *fw);
> >>> - u32 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
> >>> + u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
> >>> };
> >>>
> >>> /**
> >>> @@ -498,7 +498,7 @@ struct rproc {
> >>> int num_traces;
> >>> struct list_head carveouts;
> >>> struct list_head mappings;
> >>> - u32 bootaddr;
> >>> + u64 bootaddr;
> >>
> >> That will cause problems for rproc_coredump()[1] and fixing it properly
> >> likely means that a 32 or 64 elf should be generated based on the type of image
> >> that was loaded. This is also true if ->p_vaddr and ->p_paddr (also in the same
> >> function) are to be handled properly.
> >>
> >> I'm interested in your opinion on this.
> >
> > Indeed, you are right !
> >
> > I'm "afraid" I will have to fix that !
> > Most sane thing to do is to dump an elf with the input elf class.
> > I will make a V4 with a patch for that.
> >
>
> Actually, this does not seems directly related to elf loading.
> The coredump mecanism dumps segment that have been registered
> using rproc_coredump_add_*_segment and this is not done directly
> by the elf loader.

Correct, but it is fair to assume rpoc_coredump_add_*_segment() is called for
the image that will run on the MCU (otherwiser doing so would be pointless).

> I'm not 100% sure but the coredump elf format is not tied to
> any machine (EM_NONE) and as a special type (ET_CORE) so the elf
> type is probably not relevant adn elf64 would be generic.

That is true, we could generate an elf64 core dump for both 32 and 64 bit MCU
image and be done with it. But that is almost guaranteed to break some user
space that isn't tailored to deal with an elf64.

> If some coredump user could speak for that part, that would be
> nice !
>
> If needed, then we could add a rproc_coredump_set_format() function
> to specify various parameters (machine, elf type, lsb/msb, etc).
>

For this specific patchset I don't think you need to cover cases where this much
flexibility is needed (up to now it hasn't been a requiment).

Keeping track of the type of image being loaded in something like
rproc::elfclass and use that information to generate the right elf core in
rproc_coredump() is probably sufficient for the time being.

> Let me know what you think about it.
>
> Clément
>
> > Thanks,
> >
> > Clément
> >
> >>
> >> Thanks,
> >> Mathieu
> >>
> >> [1].
> >> https://elixir.bootlin.com/linux/latest/source/drivers/remoteproc/remoteproc_core.c#L1600
> >>
> >>> struct list_head rvdevs;
> >>> struct list_head subdevs;
> >>> struct idr notifyids;
> >>> --
> > >> 2.15.0.276.g89ea799

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