Add a generic loader
v5 cover Add a generic loader
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
Signature · 1 line
2.7.4
PATCH v5 1/3 loader: Allow ELF loader to auto-detect the ELF arch
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.
---
hw/core/loader.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
hw/core/loader.c +10 -0
@@ -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,
Signature · 1 line
2.7.4
PATCH v5 2/3 generic-loader: Add a generic loader
In reply to Alistair FrancisAdd a generic loader to QEMU which can be used to load images or set memory values.
---
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
MAINTAINERS +6 -0
@@ -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 <[email protected]> +S: Maintained +F: hw/core/generic-loader.c +F: include/hw/core/generic-loader.h + Subsystems ---------- Audio
hw/core/Makefile.objs +2 -0
@@ -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
hw/core/generic-loader.c new file +145 -0
145 lines not on this page · raw message
include/hw/core/generic-loader.h new file +45 -0
45 lines not on this page · raw message
Signature · 1 line
2.7.4
PATCH v5 3/3 docs: Add a generic loader explanation document
In reply to Alistair Francis---
V4:
- Re-write to be more comprehensive
docs/generic-loader.txt | 56 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 docs/generic-loader.txt
docs/generic-loader.txt new file +56 -0
@@ -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
Signature · 1 line
2.7.4
Re: [Qemu-devel] [PATCH v5 3/3] docs: Add a generic loader explanation document
Quoted 11 lines · Alistair Francis
Signed-off-by Alistair Francis <[email protected]>---
V4:
- Re-write to be more comprehensivedocs/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?
docs/generic-loader.txt line 19
Quoted 3 lines
docs/generic-loader.txt new file +3
-0+ +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.
docs/generic-loader.txt line 38
Quoted 3 lines
docs/generic-loader.txt new file +3
-0+ +Loading Files +---------------------------
And again
docs/generic-loader.txt line 47
Quoted 9 lines
docs/generic-loader.txt new file +9
-0+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/
Quoted 1 line
+ <cpu-num> - This specifices the CPU that should be used. This is an
s/specifices/specifies/
docs/generic-loader.txt line 53
Quoted 5 lines
docs/generic-loader.txt new file +5
-0+ 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/
Quoted 4 lines
docs/generic-loader.txt new file +3
-0+ +An example of loading an ELF file which CPU0 will boot is shown below: + -device loader,file=./images/boot.elf,cpu-num=0
Signature · 2 lines
Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
Re: [Qemu-devel] [PATCH v5 3/3] docs: Add a generic loader explanation document
Quoted 6 lines · Eric Blake
Quoted 5 lines · Alistair Francis
Signed-off-by Alistair Francis <[email protected]>---
V4:
- Re-write to be more comprehensive
Quoted 8 lines
Quoted 6 lines
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.
Quoted 7 lines
docs/generic-loader.txt line 19
Quoted 4 lines
docs/generic-loader.txt new file +3
-0+ +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.
Quoted 7 lines
docs/generic-loader.txt line 38
Quoted 5 lines
docs/generic-loader.txt new file +3
-0+ +Loading Files +---------------------------And again
Fixed.
Quoted 12 lines
docs/generic-loader.txt line 47
Quoted 10 lines
docs/generic-loader.txt new file +9
-0+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
Quoted 4 lines
Quoted 2 lines
+ <cpu-num> - This specifices the CPU that should be used. This is an
s/specifices/specifies/
Fixed
Quoted 8 lines
docs/generic-loader.txt line 53
Quoted 6 lines
docs/generic-loader.txt new file +5
-0+ 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
Quoted 10 lines
docs/generic-loader.txt line 56
Quoted 5 lines
docs/generic-loader.txt new file +3
-0+ +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