On 2 July 2016 at 02:07, Alistair Francis <[email protected]> wrote:
> Add a generic loader to QEMU which can be used to load images or set
> memory values.
>
> Signed-off-by: Alistair Francis <[email protected]>
> ---
> V8:
> - Code corrections
> - Rebase
> V7:
> - Rebase
> V6:
> - Add error checking
> 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 | 177
> +++++++++++++++++++++++++++++++++++++++
> include/hw/core/generic-loader.h | 45 ++++++++++
> 4 files changed, 230 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 2ab6e3b..0077e22 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -992,6 +992,12 @@ M: Dmitry Fleytman <[email protected]>
> S: Maintained
> F: hw/net/e1000e*
>
> +Generic Loader
> +M: Alistair Francis <[email protected]>
> +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 82a9ef8..ab238fa 100644
> --- a/hw/core/Makefile.objs
> +++ b/hw/core/Makefile.objs
> @@ -16,3 +16,5 @@ 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..c9b0572
> --- /dev/null
> +++ b/hw/core/generic-loader.c
> @@ -0,0 +1,177 @@
> +/*
> + * Generic Loader
> + *
> + * Copyright (C) 2014 Li Guang
> + * Copyright (C) 2016 Xilinx Inc.
> + * Written by Li Guang <[email protected]>
> + *
> + * 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 "qom/cpu.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
This should be updated now we've widened the type from 16 bits.
> +
> +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 something else sets the PC later on this gets lost, which is
ugly and fragile. It's kinda-sorta OK that we bodge this for things
like the hw/arm/boot.c code because all the pieces are inside QEMU,
but when you start adding in command line devices I'm a bit
nervous. Maybe we should actually figure out our reset order
woes properly ?
> + }
> + }
> +
> + 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);
We rule out specifying cpu_num below, so when is s->cpu non-NULL?
> + }
> +}
> +
> +static void generic_loader_realize(DeviceState *dev, Error **errp)
> +{
> + GenericLoaderState *s = GENERIC_LOADER(dev);
> + hwaddr entry;
> + int big_endian;
> + int size = 0;
> +
> + /* Perform some error checking on the user's options */
> + if (s->data || s->data_len || s->data_be) {
> + /* User is loading memory values */
> + if (s->file) {
> + error_setg(errp, "Specifying a file is not supported when
> loading "
> + "memory values");
> + return;
> + } else if (s->force_raw) {
> + error_setg(errp, "Specifying force raw is not supported when "
"force-raw", ie state the option name. Similarly in these other errors.
> + "loading memory values");
> + return;
> + } else if (!s->data || !s->data_len) {
> + error_setg(errp, "Both data and data length must be specified");
> + return;
> + } else if (s->cpu_num) {
> + error_setg(errp, "Setting data and a cpu number is not
> supported");
> + return;
> + }
> + } else if (s->file || s->force_raw) {
> + /* User is loading an image */
> + if (s->data || s->data_len || s->data_be) {
> + error_setg(errp, "Data can not be specified when loading an "
> + "image");
> + return;
> + }
> + } else if (s->data_len) {
> + if (s->data_len > 8) {
> + error_setg(errp, "data-len cannot be greate then 8 bytes");
"greater"
> + return;
> + } else if (s->data_len > sizeof(s->data)) {
> + error_setg(errp, "data-len cannot be more then the data size");
> + return;
> + }
> + }
> +
> + qemu_register_reset(generic_loader_reset, dev);
What's wrong with a device reset function set via dc->reset ?
> +
> + 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_as(s->file, NULL, NULL, &entry, NULL, NULL,
> + big_endian, 0, 0, 0,
> + (s->cpu ? s->cpu : first_cpu)->as);
> +
> + if (size < 0) {
> + size = load_uimage(s->file, &entry, NULL, NULL, NULL, NULL);
> + }
> + }
> +
> + if (size < 0 || s->force_raw) {
> + /* 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;
> + }
We only use the CPU's address space for ELF loads, not for uimage or raw.
That's an annoying inconsistency. I think we need to use the CPU's
address space for everything or nothing, preferably for everything.
Changing that after this goes into the tree would be a command
line compatibility break, so this inclines me to saying that this
isn't baked enough for 2.7 and we should aim to put it into 2.8.
thanks
-- PMM
