k2/prg [ Modules ]

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NAME

      prg

FUNCTION

This module provides a facility to load PRG modules into RISC-V memory.

prg/prg_s, prg/prg_t [ Types ]

[ Top ] [ prg ] [ Types ]

NAME

      struct prg_s
      prg_t

FUNCTION

The PRG format is a position-independent variation on a.out unique to the Kestrel-2EX Mantle environment. Note that this file format does not include any relocation information!

The structure of a PRG is as follows:

+--------------------+ 0 | Header | +--------------------+ 32 | Text | +--------------------+ | Read-only data | +--------------------+ text_size+32 | Read-write data | +--------------------+ data_size+text_size+32

NOTE Observe that read-only data (often, "rodata") is, for the purposes of the PRG format, considered to be part of the text segment. This may change in a future release of Mantle, as more experience with this format is obtained.

NOTE ALSO ALL SIZES must be 32-bit aligned at the minimum, 64-bit preferred.

MEMBERS

      magic
              This field MUST contain the value 0x0200006F,
              which corresponds to JAL X0,*+32 in RISC-V machine
              language.  This constant is defined in PRG_MAGIC.

      text_size
              This 32-bit field contains the number of bytes in the
              code and read-only data portions of the executable.

      data_size
              This 32-bit field contains the number of bytes in the
              read/write portion of the executable.

      bss_size
              This 32-bit field contains the size of the BSS section.
              This is a read/write data section which is assumed to
              reside immediately following the data section, and is
              assumed to be pre-initialized to zeros before the program
              is run.  Hence, there's no need to store this section's
              data, only its size.

      stack_size
              This 32-bit field contains the size of the default
              event procedure's stack.  Like the BSS section, there is
              no need to store a copy of this section in the PRG file.
              Unlike BSS, there's no presumption that it is pre-init-
              ialized to zeros.

prg/prgerr_e, prg/prgerr_t [ Types ]

[ Top ] [ prg ] [ Types ]

NAME

      enum prgerr_e
      prgerr_t

FUNCTION

Provides an indication of what went wrong while loading a PRG file into memory.

MEMBERS

      PRGLOAD_OK
              No errors occured.

      PRGLOAD_MEM_TRANSLATE
              While loading, an attempt was made to write to a memory
              location which has no corresponding reader or writer
              configured.  The memory map provided by the slots
              parameter to prg_load is not properly configured to
              cover this range of memory.

      PRGLOAD_MAGIC
              The header in the PRG file is malformed or obsolete.

      PRGLOAD_ERR_TOO_SMALL
              The header is not complete.  Alternatively: there is
              insufficient content in the file to cover the text and/
              or data sections.

      PRGLOAD_FILENAME
              The file specified to prg_load() does not exist or is
              not well formed.

SOURCE

typedef enum prgerr_e {
        PRGLOAD_OK = 0,
        PRGLOAD_MEM_TRANSLATE,
        PRGLOAD_MAGIC,
        PRGLOAD_ERR_TOO_SMALL,
        PRGLOAD_FILENAME,
} prgerr_t;