Currently we have a "Restrictions and ToDos" section at the bottom of the document which notes that there's no way to specify a CPU to load a file through that doesn't also set that CPU's PC. This is written as a developer-facing note. Move this to a TODO comment in the source code, and provide a shorter user-facing statement of the current restriction under the specific sub-option that it applies to.
Signed-off-by: Peter Maydell <[email protected]> --- docs/system/generic-loader.rst | 14 +++----------- hw/core/generic-loader.c | 18 ++++++++++++++++++ 2 files changed, 21 insertions(+), 11 deletions(-) diff --git a/docs/system/generic-loader.rst b/docs/system/generic-loader.rst index d5416711e93..0df9b66976a 100644 --- a/docs/system/generic-loader.rst +++ b/docs/system/generic-loader.rst @@ -99,6 +99,9 @@ shown below: If this option is not specified, then the data will be loaded via the address space of the first CPU, and no CPU will have its PC set. + Note that there is currently no way to specify the address space to + load the data without also causing that CPU's PC to be set. + Since it sets the starting PC, this option should only be used for the boot image. @@ -111,14 +114,3 @@ shown below: 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/hw/core/generic-loader.c b/hw/core/generic-loader.c index 433efb73872..508c090872a 100644 --- a/hw/core/generic-loader.c +++ b/hw/core/generic-loader.c @@ -30,6 +30,24 @@ * separate backend. */ +/* + * TODO: currently the "load a file" functionality provides no way + * for the user to specify which CPU address space to load the data + * into without also causing that CPU's PC to be set to the start + * address of the file. + * + * We could fix this by having a new suboption set-pc (default: true) + * so the user can say + * -device loader,file=<file>,cpu-num=<cpu-num> + * for the current "use this address space and set the PC" behaviour + * or + * -device loader,file=<file>,cpu-num=<cpu-num>,set-pc=off + * to just pick the address space and not set the PC. + * + * Using set-pc without file= should be handled as an error; otherwise + * it can feed through to what we set s->set_pc to. + */ + #include "qemu/osdep.h" #include "system/dma.h" #include "system/reset.h" -- 2.43.0
