From 085d9afc68e30b97b1d4118849a3f3c8c77ff43a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 5 Mar 2021 09:23:21 +0000 Subject: docs/system: add a gentle prompt for the complexity to come MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We all know the QEMU command line can become a fiendishly complex beast. Lets gently prepare our user for the horrors to come by referencing where other example command lines can be found in the manual. Signed-off-by: Alex Bennée Reviewed-by: Stefan Hajnoczi Reviewed-by: John Snow Reviewed-by: Thomas Huth Message-Id: <20210305092328.31792-3-alex.bennee@linaro.org> --- docs/system/quickstart.rst | 8 ++++++++ docs/system/targets.rst | 2 ++ 2 files changed, 10 insertions(+) (limited to 'docs') diff --git a/docs/system/quickstart.rst b/docs/system/quickstart.rst index 3a3acab..681678c 100644 --- a/docs/system/quickstart.rst +++ b/docs/system/quickstart.rst @@ -11,3 +11,11 @@ Download and uncompress a PC hard disk image with Linux installed (e.g. |qemu_system| linux.img Linux should boot and give you a prompt. + +Users should be aware the above example elides a lot of the complexity +of setting up a VM with x86_64 specific defaults and assumes the +first non switch argument is a PC compatible disk image with a boot +sector. For a non-x86 system where we emulate a broad range of machine +types, the command lines are generally more explicit in defining the +machine and boot behaviour. You will find more example command lines +in the :ref:`system-targets-ref` section of the manual. diff --git a/docs/system/targets.rst b/docs/system/targets.rst index 75ed108..9dcd95d 100644 --- a/docs/system/targets.rst +++ b/docs/system/targets.rst @@ -1,3 +1,5 @@ +.. _system-targets-ref: + QEMU System Emulator Targets ============================ -- cgit v1.1 From 70f20110150ec60d112bbbc9a6f8b100cd203701 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Wed, 3 Mar 2021 17:36:40 +0000 Subject: docs: move generic-loader documentation into the main manual MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We might as well surface this useful information in the manual so users can find it easily. It is a fairly simple conversion to rst with the only textual fixes being QemuOps to QemuOpts. Signed-off-by: Alex Bennée Reviewed-by: Alistair Francis Message-Id: <20210303173642.3805-6-alex.bennee@linaro.org> --- docs/generic-loader.txt | 92 -------------------------------- docs/system/generic-loader.rst | 117 +++++++++++++++++++++++++++++++++++++++++ docs/system/index.rst | 1 + 3 files changed, 118 insertions(+), 92 deletions(-) delete mode 100644 docs/generic-loader.txt create mode 100644 docs/system/generic-loader.rst (limited to 'docs') diff --git a/docs/generic-loader.txt b/docs/generic-loader.txt deleted file mode 100644 index a9603a2..0000000 --- a/docs/generic-loader.txt +++ /dev/null @@ -1,92 +0,0 @@ -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 Data into 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=,data=,data-len= - [,data-be=][,cpu-num=] - - - The address to store the data in. - - The value to be written to the address. The maximum size of - the data is 8 bytes. - - The length of the data in bytes. This argument must be - included if the data argument is. - - 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. - - The number of the CPU's address space where the data should - be loaded. If not specified the address space of the first - CPU is used. - -All values are parsed using the standard QemuOps parsing. This allows the user -to specify any values in any format supported. By default the values -will be parsed as decimal. To use hex values the user should prefix the number -with a '0x'. - -An example of loading value 0x8000000e to address 0xfd1a0104 is: - -device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4 - -Setting a CPU's Program Counter -------------------------------- -The loader device allows the CPU's PC to be set from the command line. This -can be done by following the syntax below: - - -device loader,addr=,cpu-num= - - - The value to use as the CPU's PC. - - The number of the CPU whose PC should be set to the - specified value. - -All values are parsed using the standard QemuOps parsing. This allows the user -to specify any values in any format supported. By default the values -will be parsed as decimal. To use hex values the user should prefix the number -with a '0x'. - -An example of setting CPU 0's PC to 0x8000 is: - -device loader,addr=0x8000,cpu-num=0 - -Loading Files -------------- -The loader device also allows files to be loaded into memory. It can load ELF, -U-Boot, and Intel HEX executable formats as well as raw images. The syntax is -shown below: - - -device loader,file=[,addr=][,cpu-num=][,force-raw=] - - - A file to be loaded into memory - - The memory address where the file should be loaded. This is - required for raw images and ignored for non-raw files. - - This specifies the CPU that should be used. This is an - optional argument and will cause the CPU's PC to be set to - the memory address where the raw file is loaded or the entry - point specified in the executable format header. This option - should only be used for the boot image. - This will also cause the image to be written to the specified - CPU's address space. If not specified, the default is CPU 0. - - Setting force-raw=on forces the file to be treated as a raw - image. This can be used to load supported executable formats - as if they were raw. - -All values are parsed using the standard QemuOps parsing. This allows the user -to specify any values in any format supported. By default the values -will be parsed as decimal. To use hex values the user should prefix the number -with a '0x'. - -An example of loading an ELF file which CPU0 will boot is shown below: - -device loader,file=./images/boot.elf,cpu-num=0 - -Restrictions and ToDos ----------------------- - - At the moment it is just assumed that if you specify a cpu-num then you - want to set the PC as well. This might not always be the case. In future - the internal state 'set_pc' (which exists in the generic loader now) should - be exposed to the user so that they can choose if the PC is set or not. diff --git a/docs/system/generic-loader.rst b/docs/system/generic-loader.rst new file mode 100644 index 0000000..6bf8a4e --- /dev/null +++ b/docs/system/generic-loader.rst @@ -0,0 +1,117 @@ +.. + 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. + +Generic Loader +-------------- + +The 'loader' device allows the user to load multiple images or values into +QEMU at startup. + +Loading Data into 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=,data=,data-len= \ + [,data-be=][,cpu-num=] + +```` + The address to store the data in. + +```` + The value to be written to the address. The maximum size of the data + is 8 bytes. + +```` + The length of the data in bytes. This argument must be included if + the data argument is. + +```` + 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. + +```` + The number of the CPU's address space where the data should be + loaded. If not specified the address space of the first CPU is used. + +All values are parsed using the standard QemuOps parsing. This allows the user +to specify any values in any format supported. By default the values +will be parsed as decimal. To use hex values the user should prefix the number +with a '0x'. + +An example of loading value 0x8000000e to address 0xfd1a0104 is:: + + -device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4 + +Setting a CPU's Program Counter +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The loader device allows the CPU's PC to be set from the command line. This +can be done by following the syntax below:: + + -device loader,addr=,cpu-num= + +```` + The value to use as the CPU's PC. + +```` + The number of the CPU whose PC should be set to the specified value. + +All values are parsed using the standard QemuOpts parsing. This allows the user +to specify any values in any format supported. By default the values +will be parsed as decimal. To use hex values the user should prefix the number +with a '0x'. + +An example of setting CPU 0's PC to 0x8000 is:: + + -device loader,addr=0x8000,cpu-num=0 + +Loading Files +^^^^^^^^^^^^^ + +The loader device also allows files to be loaded into memory. It can load ELF, +U-Boot, and Intel HEX executable formats as well as raw images. The syntax is +shown below: + + -device loader,file=[,addr=][,cpu-num=][,force-raw=] + +```` + A file to be loaded into memory + +```` + The memory address where the file should be loaded. This is required + for raw images and ignored for non-raw files. + +```` + This specifies the CPU that should be used. This is an + optional argument and will cause the CPU's PC to be set to the + memory address where the raw file is loaded or the entry point + specified in the executable format header. This option should only + be used for the boot image. This will also cause the image to be + written to the specified CPU's address space. If not specified, the + default is CPU 0. - Setting force-raw=on forces the file + to be treated as a raw image. This can be used to load supported + executable formats as if they were raw. + +All values are parsed using the standard QemuOpts parsing. This allows the user +to specify any values in any format supported. By default the values +will be parsed as decimal. To use hex values the user should prefix the number +with a '0x'. + +An example of loading an ELF file which CPU0 will boot is shown below:: + + -device loader,file=./images/boot.elf,cpu-num=0 + +Restrictions and ToDos +^^^^^^^^^^^^^^^^^^^^^^ + +At the moment it is just assumed that if you specify a cpu-num then +you want to set the PC as well. This might not always be the case. In +future the internal state 'set_pc' (which exists in the generic loader +now) should be exposed to the user so that they can choose if the PC +is set or not. + + diff --git a/docs/system/index.rst b/docs/system/index.rst index 625b494..cee1c83 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -25,6 +25,7 @@ Contents: usb ivshmem linuxboot + generic-loader vnc-security tls gdb -- cgit v1.1 From 0146037807831ff6424e5b8be66532ce39f0eb13 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Wed, 3 Mar 2021 17:36:41 +0000 Subject: docs: add some documentation for the guest-loader MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Alex Bennée Reviewed-by: Alistair Francis Message-Id: <20210303173642.3805-7-alex.bennee@linaro.org> --- docs/system/guest-loader.rst | 54 ++++++++++++++++++++++++++++++++++++++++++++ docs/system/index.rst | 1 + 2 files changed, 55 insertions(+) create mode 100644 docs/system/guest-loader.rst (limited to 'docs') diff --git a/docs/system/guest-loader.rst b/docs/system/guest-loader.rst new file mode 100644 index 0000000..37d03cb --- /dev/null +++ b/docs/system/guest-loader.rst @@ -0,0 +1,54 @@ +.. + Copyright (c) 2020, Linaro + +Guest Loader +------------ + +The guest loader is similar to the `generic-loader` although it is +aimed at a particular use case of loading hypervisor guests. This is +useful for debugging hypervisors without having to jump through the +hoops of firmware and boot-loaders. + +The guest loader does two things: + + - load blobs (kernels and initial ram disks) into memory + - sets platform FDT data so hypervisors can find and boot them + +This is what is typically done by a boot-loader like grub using it's +multi-boot capability. A typical example would look like: + +.. parsed-literal:: + + |qemu_system| -kernel ~/xen.git/xen/xen \ + -append "dom0_mem=1G,max:1G loglvl=all guest_loglvl=all" \ + -device guest-loader,addr=0x42000000,kernel=Image,bootargs="root=/dev/sda2 ro console=hvc0 earlyprintk=xen" \ + -device guest-loader,addr=0x47000000,initrd=rootfs.cpio + +In the above example the Xen hypervisor is loaded by the -kernel +parameter and passed it's boot arguments via -append. The Dom0 guest +is loaded into the areas of memory. Each blob will get +`/chosen/module@` entry in the FDT to indicate it's location and +size. Additional information can be passed with by using additional +arguments. + +Currently the only supported machines which use FDT data to boot are +the ARM and RiscV `virt` machines. + +Arguments +^^^^^^^^^ + +The full syntax of the guest-loader is:: + + -device guest-loader,addr=[,kernel=,[bootargs=]][,initrd=] + +``addr=`` + This is mandatory and indicates the start address of the blob. + +``kernel|initrd=`` + Indicates the filename of the kernel or initrd blob. Both blobs will + have the "multiboot,module" compatibility string as well as + "multiboot,kernel" or "multiboot,ramdisk" as appropriate. + +``bootargs=`` + This is an optional field for kernel blobs which will pass command + like via the `/chosen/module@/bootargs` node. diff --git a/docs/system/index.rst b/docs/system/index.rst index cee1c83..6ad9c93 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -26,6 +26,7 @@ Contents: ivshmem linuxboot generic-loader + guest-loader vnc-security tls gdb -- cgit v1.1