Re: [Qemu-devel] [Qemu-arm] [PATCH v4 5/6] loader: Implement .hex file loader

[sail darcy]

Thanks for your suggestion, I will review your comments carefully and take
modification in the next patch.

Best,
SU Hang

Philippe Mathieu-Daudé <address@hidden> 于2018年8月10日周五 下午3:19写道：

> Hi Su,
>
> On 08/03/2018 11:47 AM, Stefan Hajnoczi wrote:
> > From: Su Hang <address@hidden>
> >
> > This patch adds Intel Hexadecimal Object File format support to the
> > generic loader device.  The file format specification is available here:
> > http://www.piclist.com/techref/fileext/hex/intel.htm
> >
> > This file format is often used with microcontrollers such as the
> > micro:bit, Arduino, STM32, etc.  Users expect to be able to run .hex
> > files directly with without first converting them to ELF.  Most
> > micro:bit code is developed in web-based IDEs without direct user access
> > to binutils so it is important for QEMU to handle this file format
> > natively.
> >
> > Signed-off-by: Su Hang <address@hidden>
> > Signed-off-by: Stefan Hajnoczi <address@hidden>
> > ---
> >  include/hw/loader.h      |  12 ++
> >  hw/core/generic-loader.c |   4 +
> >  hw/core/loader.c         | 243 +++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 259 insertions(+)
> >
> > diff --git a/include/hw/loader.h b/include/hw/loader.h
> > index 5235f119a3..3c112975f4 100644
> > --- a/include/hw/loader.h
> > +++ b/include/hw/loader.h
> > @@ -28,6 +28,18 @@ ssize_t load_image_size(const char *filename, void
> *addr, size_t size);
> >  int load_image_targphys_as(const char *filename,
> >                             hwaddr addr, uint64_t max_sz, AddressSpace
> *as);
> >
> > +/**load_targphys_hex_as:
> > + * @filename: Path to the .hex file
> > + * @entry: Store the entry point given by the .hex file
> > + * @as: The AddressSpace to load the .hex file to. The value of
> > + *      address_space_memory is used if nothing is supplied here.
> > + *
> > + * Load a fixed .hex file into memory.
> > + *
> > + * Returns the size of the loaded .hex file on success, -1 otherwise.
> > + */
> > +int load_targphys_hex_as(const char *filename, hwaddr *entry,
> AddressSpace *as);
> > +
> >  /** load_image_targphys:
> >   * Same as load_image_targphys_as(), but doesn't allow the caller to
> specify
> >   * an AddressSpace.
> > diff --git a/hw/core/generic-loader.c b/hw/core/generic-loader.c
> > index cb0e68486d..fde32cbda1 100644
> > --- a/hw/core/generic-loader.c
> > +++ b/hw/core/generic-loader.c
> > @@ -147,6 +147,10 @@ static void generic_loader_realize(DeviceState
> *dev, Error **errp)
> >                  size = load_uimage_as(s->file, &entry, NULL, NULL,
> NULL, NULL,
> >                                        as);
> >              }
> > +
> > +            if (size < 0) {
> > +                size = load_targphys_hex_as(s->file, &entry, as);
> > +            }
> >          }
> >
> >          if (size < 0 || s->force_raw) {
> > diff --git a/hw/core/loader.c b/hw/core/loader.c
> > index 612420b870..072bf8b434 100644
> > --- a/hw/core/loader.c
> > +++ b/hw/core/loader.c
> > @@ -1321,3 +1321,246 @@ void hmp_info_roms(Monitor *mon, const QDict
> *qdict)
> >          }
> >      }
> >  }
> > +
> > +typedef enum HexRecord HexRecord;
> > +enum HexRecord {
> > +    DATA_RECORD = 0,
> > +    EOF_RECORD,
> > +    EXT_SEG_ADDR_RECORD,
> > +    START_SEG_ADDR_RECORD,
> > +    EXT_LINEAR_ADDR_RECORD,
> > +    START_LINEAR_ADDR_RECORD,
> > +};
> > +
> > +#define DATA_FIELD_MAX_LEN 0xff
> > +#define LEN_EXCEPT_DATA 0x5
> > +/* 0x5 = sizeof(byte_count) + sizeof(address) + sizeof(record_type) +
> > + *       sizeof(checksum) */
> > +typedef struct {
> > +    uint8_t byte_count;
> > +    uint16_t address;
> > +    uint8_t record_type;
> > +    uint8_t data[DATA_FIELD_MAX_LEN];
> > +    uint8_t checksum;
> > +} HexLine;
> > +
> > +/* return 0 or -1 if error */
> > +static bool parse_record(HexLine *line, uint8_t *our_checksum, const
> uint8_t c,
> > +                         uint32_t *index, const bool in_process)
> > +{
> > +    /* +-------+---------------+-------+---------------------+--------+
> > +     * | byte  |               |record |                     |        |
> > +     * | count |    address    | type  |        data         |checksum|
> > +     * +-------+---------------+-------+---------------------+--------+
> > +     * ^       ^               ^       ^                     ^        ^
> > +     * |1 byte |    2 bytes    |1 byte |     0-255 bytes     | 1 byte |
> > +     */
> > +    uint8_t value = 0;
> > +    uint32_t idx = *index;
> > +    /* ignore space */
> > +    if (g_ascii_isspace(c)) {
> > +        return true;
> > +    }
> > +    if (!g_ascii_isxdigit(c) || !in_process) {
> > +        return false;
> > +    }
> > +    value = g_ascii_xdigit_value(c);
> > +    value = idx & 0x1 ? value & 0xf : value << 4;
>
> This construction is slightly easier to read as:
>
>        value = (idx & 0x1) ? (value & 0xf) : (value << 4);
>
> > +    if (idx < 2) {
> > +        line->byte_count |= value;
> > +    } else if (2 <= idx && idx < 6) {
> > +        line->address <<= 4;
> > +        line->address += g_ascii_xdigit_value(c);
> > +    } else if (6 <= idx && idx < 8) {
> > +        line->record_type |= value;
> > +    } else if (8 <= idx && idx < 8 + 2 * line->byte_count) {
> > +        line->data[(idx - 8) >> 1] |= value;
> > +    } else if (8 + 2 * line->byte_count <= idx &&
> > +               idx < 10 + 2 * line->byte_count) {
> > +        line->checksum |= value;
> > +    } else {
> > +        return false;
> > +    }
> > +    *our_checksum += value;
> > +    ++(*index);
> > +    return true;
> > +}
> > +
> > +typedef struct {
> > +    const char *filename;
> > +    HexLine line;
> > +    uint8_t *bin_buf;
> > +    hwaddr *start_addr;
> > +    int total_size;
> > +    uint32_t next_address_to_write;
> > +    uint32_t current_address;
> > +    uint32_t current_rom_index;
> > +    uint32_t rom_start_address;
> > +    AddressSpace *as;
> > +} HexParser;
> > +
> > +/* return size or -1 if error */
> > +static int handle_record_type(HexParser *parser)
> > +{
> > +    HexLine *line = &(parser->line);
> > +    switch (line->record_type) {
> > +    case DATA_RECORD:
> > +        parser->current_address =
> > +            (parser->next_address_to_write & 0xffff0000) |
> line->address;
>
> Can you add a #define for this 0xffff0000? Maybe NEXT_ADDR_MASK 0xffff
> and use ~NEXT_ADDR_MASK.
>
> > +        /* verify this is a contiguous block of memory */
> > +        if (parser->current_address != parser->next_address_to_write) {
> > +            if (parser->current_rom_index != 0) {
> > +                rom_add_blob_fixed_as(parser->filename, parser->bin_buf,
> > +                                      parser->current_rom_index,
> > +                                      parser->rom_start_address,
> parser->as);
> > +            }
> > +            parser->rom_start_address = parser->current_address;
> > +            parser->current_rom_index = 0;
> > +        }
> > +
> > +        /* copy from line buffer to output bin_buf */
> > +        memcpy(parser->bin_buf + parser->current_rom_index, line->data,
> > +               line->byte_count);
> > +        parser->current_rom_index += line->byte_count;
> > +        parser->total_size += line->byte_count;
> > +        /* save next address to write */
> > +        parser->next_address_to_write =
> > +            parser->current_address + line->byte_count;
> > +        break;
> > +
> > +    case EOF_RECORD:
> > +        if (parser->current_rom_index != 0) {
> > +            rom_add_blob_fixed_as(parser->filename, parser->bin_buf,
> > +                                  parser->current_rom_index,
> > +                                  parser->rom_start_address,
> parser->as);
> > +        }
> > +        return parser->total_size;
> > +    case EXT_SEG_ADDR_RECORD:
> > +    case EXT_LINEAR_ADDR_RECORD:
> > +        if (line->byte_count != 2 && line->address != 0) {
> > +            return -1;
> > +        }
> > +
> > +        if (parser->current_rom_index != 0) {
> > +            rom_add_blob_fixed_as(parser->filename, parser->bin_buf,
> > +                                  parser->current_rom_index,
> > +                                  parser->rom_start_address,
> parser->as);
> > +        }
> > +
> > +        /* save next address to write,
> > +         * in case of non-contiguous block of memory */
> > +        parser->next_address_to_write =
> > +            line->record_type == EXT_SEG_ADDR_RECORD
> > +                ? ((line->data[0] << 12) | (line->data[1] << 4))
> > +                : ((line->data[0] << 24) | (line->data[1] << 16));
>
> Hard to read IMHO, what about this?
>
>            parser->next_address_to_write = (line->data[0] << 12)
>                                          | (line->data[1] << 4);
>            if (line->record_type != EXT_SEG_ADDR_RECORD) {
>                parser->next_address_to_write <<= 12;
>            }
>
> > +        parser->rom_start_address = parser->next_address_to_write;
> > +        parser->current_rom_index = 0;
> > +        break;
> > +
> > +    case START_SEG_ADDR_RECORD:
> > +        if (line->byte_count != 4 && line->address != 0) {
> > +            return -1;
> > +        }
> > +
> > +        /* x86 16-bit CS:IP segmented addressing */
> > +        *(parser->start_addr) = (((line->data[0] << 8) | line->data[1])
> << 4) |
> > +                                (line->data[2] << 8) | line->data[3];
>
> Can you add a qtest for this case?
> For the HEX loader I understand the specs as this is the same parsing as
> the START_LINEAR_ADDR_RECORD case; so I disagree with data[0] and
> data[1] shifts.
> This is different for the consumer (i386 expects 2 16-bit registers but
> HexParser->start_addr is a hwaddr, used as a single (at least) 32-bit
> register.
>
> > +        break;
> > +
> > +    case START_LINEAR_ADDR_RECORD:
> > +        if (line->byte_count != 4 && line->address != 0) {
> > +            return -1;
> > +        }
> > +
> > +        *(parser->start_addr) = (line->data[0] << 24) | (line->data[1]
> << 16) |
> > +                                (line->data[2] << 8)  | (line->data[3]);
>
> You can use this helper:
>
>            *(parser->start_addr) = ldl_be_p(line->data);
>
> > +        break;
> > +
> > +    default:
> > +        return -1;
> > +    }
> > +
> > +    return parser->total_size;
> > +}
> > +
> > +/* return size or -1 if error */
> > +static int parse_hex_blob(const char *filename, hwaddr *addr, uint8_t
> *hex_blob,
> > +                          size_t hex_blob_size, AddressSpace *as)
> > +{
> > +    bool in_process = false; /* avoid re-enter and
> > +                              * check whether record begin with ':' */
> > +    uint8_t *end = hex_blob + hex_blob_size;
> > +    uint8_t our_checksum = 0;
> > +    uint32_t record_index = 0;
> > +    HexParser parser = {
> > +        .filename = filename,
> > +        .bin_buf = g_malloc(hex_blob_size),
> > +        .start_addr = addr,
> > +        .as = as,
> > +    };
> > +
> > +    rom_transaction_begin();
> > +
> > +    for (; hex_blob < end; ++hex_blob) {
> > +        switch (*hex_blob) {
> > +        case '\r':
> > +        case '\n':
> > +            if (!in_process) {
> > +                break;
> > +            }
> > +
> > +            in_process = false;
> > +            if ((LEN_EXCEPT_DATA + parser.line.byte_count) * 2 !=
> > +                    record_index ||
> > +                our_checksum != 0) {
> > +                parser.total_size = -1;
> > +                goto out;
> > +            }
> > +
> > +            if (handle_record_type(&parser) == -1) {
> > +                parser.total_size = -1;
> > +                goto out;
> > +            }
> > +            break;
> > +
> > +        /* start of a new record. */
> > +        case ':':
> > +            memset(&parser.line, 0, sizeof(HexLine));
> > +            in_process = true;
> > +            record_index = 0;
> > +            break;
> > +
> > +        /* decoding lines */
> > +        default:
> > +            if (!parse_record(&parser.line, &our_checksum, *hex_blob,
> > +                              &record_index, in_process)) {
> > +                parser.total_size = -1;
> > +                goto out;
> > +            }
> > +            break;
> > +        }
> > +    }
> > +
> > +out:
> > +    g_free(parser.bin_buf);
> > +    rom_transaction_end(parser.total_size != -1);
> > +    return parser.total_size;
> > +}
> > +
> > +/* return size or -1 if error */
> > +int load_targphys_hex_as(const char *filename, hwaddr *entry,
> AddressSpace *as)
> > +{
> > +    gsize hex_blob_size;
> > +    gchar *hex_blob;
> > +    int total_size = 0;
> > +
> > +    if (!g_file_get_contents(filename, &hex_blob, &hex_blob_size,
> NULL)) {
> > +        return -1;
> > +    }
> > +
> > +    total_size = parse_hex_blob(filename, entry, (uint8_t *)hex_blob,
> > +                                hex_blob_size, as);
> > +
> > +    g_free(hex_blob);
> > +    return total_size;
> > +}
> >
>
> Regards,
>
> Phil.
>
>