Re: [PATCH rc4 23/29] hw/avr: Add helper to load raw/ELF firmware binaries

[Aleksandar Markovic <aleksandar.m.mail@gmail.com>]

On Fri, Jan 31, 2020 at 1:20 AM Philippe Mathieu-Daudé
<philmd@redhat.com> wrote:
>
> On 1/31/20 1:03 AM, Aleksandar Markovic wrote:
> > From: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >
> > Add avr_load_firmware() function to load firmware in ELF or
> > raw binary format.
> >
> > [AM: Corrected the type of the variable containing e_flags]
> >
> > Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
> > ---
> >   hw/avr/Makefile.objs |  1 +
> >   hw/avr/boot.c        | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   hw/avr/boot.h        | 33 +++++++++++++++++++++++
> >   include/elf.h        |  2 ++
> >   4 files changed, 110 insertions(+)
> >   create mode 100644 hw/avr/Makefile.objs
> >   create mode 100644 hw/avr/boot.c
> >   create mode 100644 hw/avr/boot.h
> >
> > diff --git a/hw/avr/Makefile.objs b/hw/avr/Makefile.objs
> > new file mode 100644
> > index 0000000..123f174
> > --- /dev/null
> > +++ b/hw/avr/Makefile.objs
> > @@ -0,0 +1 @@
> > +obj-y += boot.o
> > diff --git a/hw/avr/boot.c b/hw/avr/boot.c
> > new file mode 100644
> > index 0000000..9ac2c88
> > --- /dev/null
> > +++ b/hw/avr/boot.c
> > @@ -0,0 +1,74 @@
> > +/*
> > + * AVR loader helpers
> > + *
> > + * Copyright (c) 2019 Philippe Mathieu-Daudé
> > + *
> > + * This work is licensed under the terms of the GNU GPLv2 or later.
> > + * See the COPYING file in the top-level directory.
> > + * SPDX-License-Identifier: GPL-2.0-or-later
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "qemu-common.h"
> > +#include "hw/loader.h"
> > +#include "elf.h"
> > +#include "boot.h"
> > +#include "qemu/error-report.h"
> > +
> > +bool avr_load_firmware(AVRCPU *cpu, MachineState *ms,
> > +                       MemoryRegion *mr, const char *firmware)
> > +{
> > +    const char *filename;
> > +    int bytes_loaded;
> > +    uint64_t entry;
> > +    uint32_t e_flags;
> > +
> > +    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware);
> > +    if (filename == NULL) {
> > +        error_report("Unable to find %s", firmware);
> > +        return false;
> > +    }
> > +
> > +    bytes_loaded = load_elf_ram_sym(filename,
> > +                                    NULL, NULL, NULL,
> > +                                    &entry, NULL, NULL,
> > +                                    &e_flags, 0, EM_AVR, 0, 0,
> > +                                    NULL, true, NULL);
> > +    if (bytes_loaded >= 0) {
> > +        /* If ELF file is provided, determine CPU type reading ELF e_flags. */
> > +        const char *elf_cpu = avr_flags_to_cpu_type(e_flags, NULL);
> > +        const char *mcu_cpu_type = object_get_typename(OBJECT(cpu));
> > +        int cpu_len = strlen(mcu_cpu_type) - strlen(AVR_CPU_TYPE_SUFFIX);
> > +
> > +        if (entry) {
> > +            error_report("BIOS entry_point must be 0x0000 "
> > +                         "(ELF image '%s' has entry_point 0x%04" PRIx64 ")",
> > +                         firmware, entry);
> > +            return false;
> > +        }
> > +        if (!elf_cpu) {
> > +            warn_report("Could not determine CPU type for ELF image '%s', "
> > +                        "assuming '%.*s' CPU",
> > +                         firmware, cpu_len, mcu_cpu_type);
> > +            return true;
> > +        }
> > +        if (strcmp(elf_cpu, mcu_cpu_type)) {
> > +            error_report("Current machine: %s with '%.*s' CPU",
> > +                         MACHINE_GET_CLASS(ms)->desc, cpu_len, mcu_cpu_type);
> > +            error_report("ELF image '%s' is for '%.*s' CPU",
> > +                         firmware,
> > +                         (int)(strlen(elf_cpu) - strlen(AVR_CPU_TYPE_SUFFIX)),
> > +                         elf_cpu);
> > +            return false;
> > +        }
> > +    } else {
> > +        bytes_loaded = load_image_targphys(filename, OFFSET_CODE,
> > +                                           memory_region_size(mr));
> > +    }
> > +    if (bytes_loaded < 0) {
> > +        error_report("Unable to load firmware image %s as ELF or raw binary",
> > +                     firmware);
> > +        return false;
> > +    }
> > +    return true;
> > +}
> > diff --git a/hw/avr/boot.h b/hw/avr/boot.h
> > new file mode 100644
> > index 0000000..62bc10c
> > --- /dev/null
> > +++ b/hw/avr/boot.h
> > @@ -0,0 +1,33 @@
> > +/*
> > + * AVR loader helpers
> > + *
> > + * Copyright (c) 2019 Philippe Mathieu-Daudé
> > + *
> > + * This work is licensed under the terms of the GNU GPLv2 or later.
> > + * See the COPYING file in the top-level directory.
> > + * SPDX-License-Identifier: GPL-2.0-or-later
> > + */
> > +
> > +#ifndef HW_AVR_BOOT_H
> > +#define HW_AVR_BOOT_H
> > +
> > +#include "hw/boards.h"
> > +#include "cpu.h"
> > +
> > +/**
> > + * avr_load_firmware:   load an image into a memory region
> > + *
> > + * @cpu:        Handle a AVR CPU object
> > + * @ms:         A MachineState
> > + * @mr:         Memory Region to load into
> > + * @firmware:   Path to the firmware file (raw binary or ELF format)
> > + *
> > + * Load a firmware supplied by the machine or by the user  with the
> > + * '-bios' command line option, and put it in target memory.
> > + *
> > + * Returns: true on success, false on error.
> > + */
> > +bool avr_load_firmware(AVRCPU *cpu, MachineState *ms,
> > +                       MemoryRegion *mr, const char *firmware);
> > +
> > +#endif
> > diff --git a/include/elf.h b/include/elf.h
> > index 8fbfe60..3f08f68 100644
> > --- a/include/elf.h
> > +++ b/include/elf.h
> > @@ -202,6 +202,8 @@ typedef struct mips_elf_abiflags_v0 {
> >   #define EM_MOXIE           223     /* Moxie processor family */
> >   #define EM_MOXIE_OLD       0xFEED
> >
> > +#define EM_AVR 83 /* AVR 8-bit microcontroller */
>
> IIRC from previous version you suggested to move this, I suppose between:
>
> #define EM_CRIS         76
>
> #define EM_V850         87
>

I forgot about that, thinking about other larger changes.

> > +
> >   /* This is the info that is needed to parse the dynamic section of the file */
> >   #define DT_NULL             0
> >   #define DT_NEEDED   1
> >
>