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

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 1/31/20 1:26 AM, Aleksandar Markovic wrote:
> 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.

Anyway looking closer, the definitions are not ordered correctly, so I 
think we don't care much. Your call :)

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