hw/core/loader: Let load_elf() populate a field with CPU-specific flags

While loading the executable, some platforms (like AVR) need to
detect CPU type that executable is built for - and, with this patch,
this is enabled by reading the field 'e_flags' of the ELF header of
the executable in question. The change expands functionality of
the following functions:

  - load_elf()
  - load_elf_as()
  - load_elf_ram()
  - load_elf_ram_sym()

The argument added to these functions is called 'pflags' and is of
type 'uint32_t*' (that matches 'pointer to 'elf_word'', 'elf_word'
being the type of the field 'e_flags', in both 32-bit and 64-bit
variants of ELF header). Callers are allowed to pass NULL as that
argument, and in such case no lookup to the field 'e_flags' will
happen, and no information will be returned, of course.

CC: Richard Henderson <rth@twiddle.net>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Edgar E. Iglesias <edgar.iglesias@gmail.com>
CC: Michael Walle <michael@walle.cc>
CC: Thomas Huth <huth@tuxfamily.org>
CC: Laurent Vivier <laurent@vivier.eu>
CC: Philippe Mathieu-Daudé <f4bug@amsat.org>
CC: Aleksandar Rikalo <aleksandar.rikalo@rt-rk.com>
CC: Aurelien Jarno <aurelien@aurel32.net>
CC: Jia Liu <proljc@gmail.com>
CC: David Gibson <david@gibson.dropbear.id.au>
CC: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
CC: BALATON Zoltan <balaton@eik.bme.hu>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Thomas Huth <thuth@redhat.com>
CC: Artyom Tarasenko <atar4qemu@gmail.com>
CC: Fabien Chouteau <chouteau@adacore.com>
CC: KONRAD Frederic <frederic.konrad@adacore.com>
CC: Max Filippov <jcmvbkbc@gmail.com>

Reviewed-by: Aleksandar Rikalo <aleksandar.rikalo@rt-rk.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Message-Id: <1580079311-20447-24-git-send-email-aleksandar.markovic@rt-rk.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 5099f27..d1b78f6 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -406,12 +406,12 @@ int load_elf(const char *filename,
              uint64_t (*elf_note_fn)(void *, void *, bool),
              uint64_t (*translate_fn)(void *, uint64_t),
              void *translate_opaque, uint64_t *pentry, uint64_t *lowaddr,
-             uint64_t *highaddr, int big_endian, int elf_machine,
-             int clear_lsb, int data_swab)
+             uint64_t *highaddr, uint32_t *pflags, int big_endian,
+             int elf_machine, int clear_lsb, int data_swab)
 {
     return load_elf_as(filename, elf_note_fn, translate_fn, translate_opaque,
-                       pentry, lowaddr, highaddr, big_endian, elf_machine,
-                       clear_lsb, data_swab, NULL);
+                       pentry, lowaddr, highaddr, pflags, big_endian,
+                       elf_machine, clear_lsb, data_swab, NULL);
 }
 
 /* return < 0 if error, otherwise the number of bytes loaded in memory */
@@ -419,12 +419,12 @@ int load_elf_as(const char *filename,
                 uint64_t (*elf_note_fn)(void *, void *, bool),
                 uint64_t (*translate_fn)(void *, uint64_t),
                 void *translate_opaque, uint64_t *pentry, uint64_t *lowaddr,
-                uint64_t *highaddr, int big_endian, int elf_machine,
-                int clear_lsb, int data_swab, AddressSpace *as)
+                uint64_t *highaddr, uint32_t *pflags, int big_endian,
+                int elf_machine, int clear_lsb, int data_swab, AddressSpace *as)
 {
     return load_elf_ram(filename, elf_note_fn, translate_fn, translate_opaque,
-                        pentry, lowaddr, highaddr, big_endian, elf_machine,
-                        clear_lsb, data_swab, as, true);
+                        pentry, lowaddr, highaddr, pflags, big_endian,
+                        elf_machine, clear_lsb, data_swab, as, true);
 }
 
 /* return < 0 if error, otherwise the number of bytes loaded in memory */
@@ -432,13 +432,13 @@ int load_elf_ram(const char *filename,
                  uint64_t (*elf_note_fn)(void *, void *, bool),
                  uint64_t (*translate_fn)(void *, uint64_t),
                  void *translate_opaque, uint64_t *pentry, uint64_t *lowaddr,
-                 uint64_t *highaddr, int big_endian, int elf_machine,
-                 int clear_lsb, int data_swab, AddressSpace *as,
-                 bool load_rom)
+                 uint64_t *highaddr, uint32_t *pflags, int big_endian,
+                 int elf_machine, int clear_lsb, int data_swab,
+                 AddressSpace *as, bool load_rom)
 {
     return load_elf_ram_sym(filename, elf_note_fn,
                             translate_fn, translate_opaque,
-                            pentry, lowaddr, highaddr, big_endian,
+                            pentry, lowaddr, highaddr, pflags, big_endian,
                             elf_machine, clear_lsb, data_swab, as,
                             load_rom, NULL);
 }
@@ -448,8 +448,9 @@ int load_elf_ram_sym(const char *filename,
                      uint64_t (*elf_note_fn)(void *, void *, bool),
                      uint64_t (*translate_fn)(void *, uint64_t),
                      void *translate_opaque, uint64_t *pentry,
-                     uint64_t *lowaddr, uint64_t *highaddr, int big_endian,
-                     int elf_machine, int clear_lsb, int data_swab,
+                     uint64_t *lowaddr, uint64_t *highaddr, uint32_t *pflags,
+                     int big_endian, int elf_machine,
+                     int clear_lsb, int data_swab,
                      AddressSpace *as, bool load_rom, symbol_fn_t sym_cb)
 {
     int fd, data_order, target_data_order, must_swab, ret = ELF_LOAD_FAILED;
@@ -490,13 +491,13 @@ int load_elf_ram_sym(const char *filename,
     if (e_ident[EI_CLASS] == ELFCLASS64) {
         ret = load_elf64(filename, fd, elf_note_fn,
                          translate_fn, translate_opaque, must_swab,
-                         pentry, lowaddr, highaddr, elf_machine, clear_lsb,
-                         data_swab, as, load_rom, sym_cb);
+                         pentry, lowaddr, highaddr, pflags, elf_machine,
+                         clear_lsb, data_swab, as, load_rom, sym_cb);
     } else {
         ret = load_elf32(filename, fd, elf_note_fn,
                          translate_fn, translate_opaque, must_swab,
-                         pentry, lowaddr, highaddr, elf_machine, clear_lsb,
-                         data_swab, as, load_rom, sym_cb);
+                         pentry, lowaddr, highaddr, pflags, elf_machine,
+                         clear_lsb, data_swab, as, load_rom, sym_cb);
     }
 
  fail: