[Qemu-devel] [PATCH v5 0/3] Add a generic loader

[Qemu-devel] [PATCH v5 0/3] Add a generic loader

[Alistair Francis]

This work is based on the original work by Li Guang with extra
features added by Peter C and myself.

The idea of this loader is to allow the user to load multiple images
or values into QEMU at startup.

Memory values can be loaded like this: -device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4

Images can be loaded like this: -device loader,file=./images/u-boot.elf,cpu=0

This can be useful and we use it a lot in Xilinx to load multiple images
into a machine at creation (ATF, Kernel and DTB for example).

It can also be used to set registers.

This patch series also make the load_elf() function more generic by not
requiring an architecture.

V5:
 - Rebase
V4:
 - Re-write documentation
 - Allow the loader to work with every architecture
 - Move the file to hw/core
 - Increase the maximum number of CPUs
 - Make the CPU operations conditional
 - Convert the cpu option to cpu-num
 - Require the user to specify endianess
V2:
 - Add an entry to the maintainers file
 - Add some documentation
 - Perform bounds checking on the data_len
 - Register and unregister the reset in the realise/unrealise
Changes since RFC:
 - Add support for BE


Alistair Francis (3):
  loader: Allow ELF loader to auto-detect the ELF arch
  generic-loader: Add a generic loader
  docs: Add a generic loader explanation document

 MAINTAINERS                      |   6 ++
 docs/generic-loader.txt          |  56 +++++++++++++++
 hw/core/Makefile.objs            |   2 +
 hw/core/generic-loader.c         | 145 +++++++++++++++++++++++++++++++++++++++
 hw/core/loader.c                 |  10 +++
 include/hw/core/generic-loader.h |  45 ++++++++++++
 6 files changed, 264 insertions(+)
 create mode 100644 docs/generic-loader.txt
 create mode 100644 hw/core/generic-loader.c
 create mode 100644 include/hw/core/generic-loader.h

-- 
2.7.4

[Qemu-devel] [PATCH v5 1/3] loader: Allow ELF loader to auto-detect the ELF arch

[Alistair Francis]

If the caller didn't specify an architecture for the ELF machine
the load_elf() function will auto detect it based on the ELF file.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
---

 hw/core/loader.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index c049957..6b8be6b 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -419,6 +419,7 @@ int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
 {
     int fd, data_order, target_data_order, must_swab, ret = ELF_LOAD_FAILED;
     uint8_t e_ident[EI_NIDENT];
+    uint16_t e_machine;
 
     fd = open(filename, O_RDONLY | O_BINARY);
     if (fd < 0) {
@@ -451,6 +452,15 @@ int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
         goto fail;
     }
 
+    if (elf_machine < 1) {
+        /* The caller didn't specify and ARCH, we can figure it out */
+        lseek(fd, 0x12, SEEK_SET);
+        if (read(fd, &e_machine, sizeof(e_machine)) != sizeof(e_machine)) {
+            goto fail;
+        }
+        elf_machine = e_machine;
+    }
+
     lseek(fd, 0, SEEK_SET);
     if (e_ident[EI_CLASS] == ELFCLASS64) {
         ret = load_elf64(filename, fd, translate_fn, translate_opaque, must_swab,
-- 
2.7.4

[Qemu-devel] [PATCH v5 2/3] generic-loader: Add a generic loader

[Alistair Francis]

Add a generic loader to QEMU which can be used to load images or set
memory values.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
---
V5:
 - Rebase
V4:
 - Allow the loader to work with every architecture
 - Move the file to hw/core
 - Increase the maximum number of CPUs
 - Make the CPU operations conditional
 - Convert the cpu option to cpu-num
 - Require the user to specify endianess
V3:
 - Pass the ram_size to load_image_targphys()
V2:
 - Add maintainers entry
 - Perform bounds checking
 - Register and unregister the reset in the realise/unrealise
Changes since RFC:
 - Add BE support

 MAINTAINERS                      |   6 ++
 hw/core/Makefile.objs            |   2 +
 hw/core/generic-loader.c         | 145 +++++++++++++++++++++++++++++++++++++++
 include/hw/core/generic-loader.h |  45 ++++++++++++
 4 files changed, 198 insertions(+)
 create mode 100644 hw/core/generic-loader.c
 create mode 100644 include/hw/core/generic-loader.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 81e7fac..b4a77d8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -972,6 +972,12 @@ F: hw/acpi/nvdimm.c
 F: hw/mem/nvdimm.c
 F: include/hw/mem/nvdimm.h
 
+Generic Loader
+M: Alistair Francis <alistair.francis@xilinx.com>
+S: Maintained
+F: hw/core/generic-loader.c
+F: include/hw/core/generic-loader.h
+
 Subsystems
 ----------
 Audio
diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index abb3560..b5d5197 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -15,3 +15,5 @@ common-obj-$(CONFIG_SOFTMMU) += null-machine.o
 common-obj-$(CONFIG_SOFTMMU) += loader.o
 common-obj-$(CONFIG_SOFTMMU) += qdev-properties-system.o
 common-obj-$(CONFIG_PLATFORM_BUS) += platform-bus.o
+
+obj-$(CONFIG_SOFTMMU) += generic-loader.o
diff --git a/hw/core/generic-loader.c b/hw/core/generic-loader.c
new file mode 100644
index 0000000..9e114f4
--- /dev/null
+++ b/hw/core/generic-loader.c
@@ -0,0 +1,145 @@
+/*
+ * Generic Loader
+ *
+ * Copyright (C) 2014 Li Guang
+ * Copyright (C) 2016 Xilinx Inc.
+ * Written by Li Guang <lig.fnst@cn.fujitsu.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "sysemu/dma.h"
+#include "hw/loader.h"
+#include "qapi/error.h"
+#include "hw/core/generic-loader.h"
+
+#define CPU_NONE 0xFFFF
+
+static void generic_loader_reset(void *opaque)
+{
+    GenericLoaderState *s = GENERIC_LOADER(opaque);
+
+    if (s->cpu) {
+        CPUClass *cc = CPU_GET_CLASS(s->cpu);
+        cpu_reset(s->cpu);
+        if (cc) {
+            cc->set_pc(s->cpu, s->addr);
+        }
+    }
+
+    if (s->data_len) {
+        assert(s->data_len < sizeof(s->data));
+        dma_memory_write((s->cpu ? s->cpu : first_cpu)->as, s->addr, &s->data,
+                         s->data_len);
+    }
+}
+
+static void generic_loader_realize(DeviceState *dev, Error **errp)
+{
+    GenericLoaderState *s = GENERIC_LOADER(dev);
+    hwaddr entry;
+    int big_endian;
+    int size = 0;
+
+    qemu_register_reset(generic_loader_reset, dev);
+
+    if (s->cpu_num != CPU_NONE) {
+        s->cpu = qemu_get_cpu(s->cpu_num);
+        if (!s->cpu) {
+            error_setg(errp, "Specified boot CPU#%d is nonexistent",
+                       s->cpu_num);
+            return;
+        }
+    }
+
+#ifdef TARGET_WORDS_BIGENDIAN
+    big_endian = 1;
+#else
+    big_endian = 0;
+#endif
+
+    if (s->file) {
+        if (!s->force_raw) {
+            size = load_elf(s->file, NULL, NULL, &entry, NULL, NULL,
+                            big_endian, 0, 0, 0);
+
+            if (size < 0) {
+                size = load_uimage(s->file, &entry, NULL, NULL, NULL, NULL);
+            }
+        }
+
+        if (size < 0) {
+            /* Default to the maximum size being the machine's ram size */
+            size = load_image_targphys(s->file, s->addr, ram_size);
+        } else {
+            s->addr = entry;
+        }
+
+        if (size < 0) {
+            error_setg(errp, "Cannot load specified image %s", s->file);
+            return;
+        }
+    }
+
+    if (s->data_len && (s->data_len > sizeof(s->data))) {
+        error_setg(errp, "data-len cannot be more then the data size");
+        return;
+    }
+
+    /* Convert the data endiannes */
+    if (s->data_be) {
+        s->data = cpu_to_be64(s->data);
+    } else {
+        s->data = cpu_to_le64(s->data);
+    }
+}
+
+static void generic_loader_unrealize(DeviceState *dev, Error **errp)
+{
+    qemu_unregister_reset(generic_loader_reset, dev);
+}
+
+static Property generic_loader_props[] = {
+    DEFINE_PROP_UINT64("addr", GenericLoaderState, addr, 0),
+    DEFINE_PROP_UINT64("data", GenericLoaderState, data, 0),
+    DEFINE_PROP_UINT8("data-len", GenericLoaderState, data_len, 0),
+    DEFINE_PROP_BOOL("data-be", GenericLoaderState, data_be, false),
+    DEFINE_PROP_UINT16("cpu-num", GenericLoaderState, cpu_num, CPU_NONE),
+    DEFINE_PROP_BOOL("force-raw", GenericLoaderState, force_raw, false),
+    DEFINE_PROP_STRING("file", GenericLoaderState, file),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void generic_loader_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = generic_loader_realize;
+    dc->unrealize = generic_loader_unrealize;
+    dc->props = generic_loader_props;
+    dc->desc = "Generic Loader";
+}
+
+static TypeInfo generic_loader_info = {
+    .name = TYPE_GENERIC_LOADER,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(GenericLoaderState),
+    .class_init = generic_loader_class_init,
+};
+
+static void generic_loader_register_type(void)
+{
+    type_register_static(&generic_loader_info);
+}
+
+type_init(generic_loader_register_type)
diff --git a/include/hw/core/generic-loader.h b/include/hw/core/generic-loader.h
new file mode 100644
index 0000000..ceec51f
--- /dev/null
+++ b/include/hw/core/generic-loader.h
@@ -0,0 +1,45 @@
+/*
+ * Generic Loader
+ *
+ * Copyright (C) 2014 Li Guang
+ * Written by Li Guang <lig.fnst@cn.fujitsu.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#ifndef GENERIC_LOADER_H
+#define GENERIC_LOADER_H
+
+#include "elf.h"
+
+typedef struct GenericLoaderState {
+    /* <private> */
+    DeviceState parent_obj;
+
+    /* <public> */
+    CPUState *cpu;
+
+    uint64_t addr;
+    uint64_t data;
+    uint8_t data_len;
+    uint16_t cpu_num;
+
+    char *file;
+
+    bool force_raw;
+    bool data_be;
+} GenericLoaderState;
+
+#define TYPE_GENERIC_LOADER "loader"
+#define GENERIC_LOADER(obj) OBJECT_CHECK(GenericLoaderState, (obj), \
+                                         TYPE_GENERIC_LOADER)
+
+#endif
-- 
2.7.4

[Qemu-devel] [PATCH v5 3/3] docs: Add a generic loader explanation document

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
---
V4:
 - Re-write to be more comprehensive

 docs/generic-loader.txt | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 docs/generic-loader.txt

diff --git a/docs/generic-loader.txt b/docs/generic-loader.txt
new file mode 100644
index 0000000..b748f2a
--- /dev/null
+++ b/docs/generic-loader.txt
@@ -0,0 +1,56 @@
+Copyright (c) 2016 Xilinx Inc.
+
+This work is licensed under the terms of the GNU GPL, version 2 or later.  See
+the COPYING file in the top-level directory.
+
+
+The 'loader' device allows the user to load multiple images or values into
+QEMU at startup.
+
+Loading Memory Values
+---------------------------
+The loader device allows memory values to be set from the command line. This
+can be done by following the syntax below:
+
+    -device loader,addr=<addr>,data=<data>,data-len=<len>
+    -device loader,addr=<addr>,cpu-num=<cpu-num>
+
+NOTE: The loader device supports other options (see the next section) but they
+      do not apply to setting memory values and will be ignored.
+      It is also possible to mix the commands above, e.g. include the cpu-num
+      argument with the data argument.
+
+    <addr>      - The address to store the data or the value to set the CPUs PC
+    <data>      - The value to be written to the addr. The maximum size of the
+                  data is 8 bytes.
+    <data-len>  - The length of the data in bytes. This argument must be included
+                  if the data argument is.
+    <data-be>   - Set to true if the data to be stored on the guest should be
+                  written as big endian data. The default is to write little
+                  endian data.
+    <cpu-num>   - This will cause the CPU to be reset and the PC to be set to
+                  the value of addr.
+
+An example of loading value 0x8000000e to address 0xfd1a0104 is:
+    -device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4
+
+Loading Files
+---------------------------
+The loader device also allows files to be loaded into memory. This can be done
+similarly to setting memory values. The syntax is shown below:
+
+    -device loader,file=<file>,addr=<addr>,cpu-num=<cpu-num>,force-raw=<raw>
+
+    <file>      - A file to be loaded into memory
+    <addr>      - The addr in memory that the file should be loaded. This is
+                  ignored if you are using an ELF (unless force-raw is true).
+                  This is requried if you aren't loading an ELF.
+    <cpu-num>   - This specifices the CPU that should be used. This is an
+                  optional argument and will cause the CPU's PC to be set to
+                  where the image is stored. This option should only be used
+                  for the boot image.
+    <force-raw> - Forces the file to be treated as a raw image. This can be
+                  used to specificy the load address of ELF files.
+
+An example of loading an ELF file which CPU0 will boot is shown below:
+    -device loader,file=./images/boot.elf,cpu-num=0
-- 
2.7.4

Re: [Qemu-devel] [PATCH v5 3/3] docs: Add a generic loader explanation document

[Eric Blake]

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On 05/12/2016 10:13 AM, Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
> ---
> V4:
>  - Re-write to be more comprehensive
> 
>  docs/generic-loader.txt | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 docs/generic-loader.txt

> +Loading Memory Values
> +---------------------------

Worth matching ---- line length to the line above?

> +
> +NOTE: The loader device supports other options (see the next section) but they
> +      do not apply to setting memory values and will be ignored.

Ignoring invalid option combinations is not as friendly as outright
rejecting them.


> +
> +Loading Files
> +---------------------------

And again

> +The loader device also allows files to be loaded into memory. This can be done
> +similarly to setting memory values. The syntax is shown below:
> +
> +    -device loader,file=<file>,addr=<addr>,cpu-num=<cpu-num>,force-raw=<raw>
> +
> +    <file>      - A file to be loaded into memory
> +    <addr>      - The addr in memory that the file should be loaded. This is
> +                  ignored if you are using an ELF (unless force-raw is true).
> +                  This is requried if you aren't loading an ELF.

s/requried/required/

> +    <cpu-num>   - This specifices the CPU that should be used. This is an

s/specifices/specifies/

> +                  optional argument and will cause the CPU's PC to be set to
> +                  where the image is stored. This option should only be used
> +                  for the boot image.
> +    <force-raw> - Forces the file to be treated as a raw image. This can be
> +                  used to specificy the load address of ELF files.

s/specificy/specify/

> +
> +An example of loading an ELF file which CPU0 will boot is shown below:
> +    -device loader,file=./images/boot.elf,cpu-num=0
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 3/3] docs: Add a generic loader explanation document

[Alistair Francis]

On Thu, May 12, 2016 at 9:24 AM, Eric Blake <eblake@redhat.com> wrote:
> On 05/12/2016 10:13 AM, Alistair Francis wrote:
>> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
>> ---
>> V4:
>>  - Re-write to be more comprehensive
>>
>>  docs/generic-loader.txt | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 56 insertions(+)
>>  create mode 100644 docs/generic-loader.txt
>
>> +Loading Memory Values
>> +---------------------------
>
> Worth matching ---- line length to the line above?

Good point, fixed.

>
>> +
>> +NOTE: The loader device supports other options (see the next section) but they
>> +      do not apply to setting memory values and will be ignored.
>
> Ignoring invalid option combinations is not as friendly as outright
> rejecting them.

Ok, I have added stricter checking to cover most invalid use cases.

>
>
>> +
>> +Loading Files
>> +---------------------------
>
> And again

Fixed.

>
>> +The loader device also allows files to be loaded into memory. This can be done
>> +similarly to setting memory values. The syntax is shown below:
>> +
>> +    -device loader,file=<file>,addr=<addr>,cpu-num=<cpu-num>,force-raw=<raw>
>> +
>> +    <file>      - A file to be loaded into memory
>> +    <addr>      - The addr in memory that the file should be loaded. This is
>> +                  ignored if you are using an ELF (unless force-raw is true).
>> +                  This is requried if you aren't loading an ELF.
>
> s/requried/required/

Fixed

>
>> +    <cpu-num>   - This specifices the CPU that should be used. This is an
>
> s/specifices/specifies/

Fixed

>
>> +                  optional argument and will cause the CPU's PC to be set to
>> +                  where the image is stored. This option should only be used
>> +                  for the boot image.
>> +    <force-raw> - Forces the file to be treated as a raw image. This can be
>> +                  used to specificy the load address of ELF files.
>
> s/specificy/specify/

Fixed.

Thanks for reading the patch.

Alistair

>
>> +
>> +An example of loading an ELF file which CPU0 will boot is shown below:
>> +    -device loader,file=./images/boot.elf,cpu-num=0
>>
>
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>