Revert "elf: Relax MIPS' elf_check_arch() to accept EM_NANOMIPS too"

Per the "P32 Porting Guide" (rev 1.2) [1], chapter 2:

  p32 ABI Overview
  ----------------

  The Application Binary Interface, or ABI, is the set of rules
  that all binaries must follow in order to run on a nanoMIPS
  system. This includes, for example, object file format,
  instruction set, data layout, subroutine calling convention,
  and system call numbers. The ABI is one part of the mechanism
  that maintains binary compatibility across all nanoMIPS platforms.

  p32 improves on o32 to provide an ABI that is efficient in both
  code density and performance. p32 is required for the nanoMIPS
  architecture.

So far QEMU only support the MIPS o32 / n32 / n64 ABIs. The p32 ABI
is not implemented, therefore we can not run any nanoMIPS binary.

Revert commit f72541f3a59 ("elf: Relax MIPS' elf_check_arch() to
accept EM_NANOMIPS too").

See also the "ELF ABI Supplement" [2].

[1] http://codescape.mips.com/components/toolchain/nanomips/2019.03-01/docs/MIPS_nanoMIPS_p32_ABI_Porting_Guide_01_02_DN00184.pdf
[2] http://codescape.mips.com/components/toolchain/nanomips/2019.03-01/docs/MIPS_nanoMIPS_ABI_supplement_01_03_DN00179.pdf

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211101114800.2692157-1-f4bug@amsat.org>

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index f9b8261692085e30bb5dba220c5ec196cf04f056..5da8c02d08225aedfbffac3013ffd878aeb19e60 100644 (file)
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -925,8 +925,6 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUPPCState *en
 #endif
 #define ELF_ARCH    EM_MIPS
 
-#define elf_check_arch(x) ((x) == EM_MIPS || (x) == EM_NANOMIPS)
-
 #ifdef TARGET_ABI_MIPSN32
 #define elf_check_abi(x) ((x) & EF_MIPS_ABI2)
 #else