e2k: implement detecting ISA version by ELF flags, throw an error for protected mode and x86 recompiled binaries for now

linux-user/e2k/cpu_loop.c

@@ -21,6 +21,7 @@
 #include "qemu-common.h"
 #include "qemu.h"
 #include "cpu_loop-common.h"
+#include "target_elf.h"
 
 void helper_return(CPUE2KState *env);
 
@@ -118,15 +119,50 @@ void cpu_loop(CPUE2KState *env)
 
 void target_cpu_copy_regs(CPUE2KState *env, struct target_pt_regs *regs)
 {
+    CPUState *cpu = env_cpu(env);
+    TaskState *ts = cpu->opaque;
+    struct image_info *info = ts->info;
+    uint32_t eflags = info->elf_flags;
+
     env->ip = regs->ip;
     env->pcsp = regs->pcsp;
     env->psp = regs->psp;
     env->usd.lo = regs->usd_lo;
     env->usd.hi = regs->usd_hi;
     env->sbr = regs->sbr;
+    env->elf_flags = info->elf_flags;
+
+    if (eflags & E2K_ELF_PM) {
+        fprintf(stderr, "Protected mode is unsupported\n");
+        exit(EXIT_FAILURE);
+    }
+
+    if (eflags & E2K_ELF_X86APP) {
+        fprintf(stderr, "x86 recompiler is unsupported\n");
+        exit(EXIT_FAILURE);
+    }
 
     e2k_break_save_state(env);
 
     env->pcs_base = env->pcsp.base;
     env->ps_base = env->psp.base;
 }
+
+const char *cpu_get_model(uint32_t eflags)
+{
+    const char *name = "any";
+    uint32_t machine = E2K_ELF_MACH(eflags);
+
+    /* TODO: can't check for EM_E2K_OLD flags because e_machine isn't saved anywhere... */
+    switch(machine) {
+    case E2K_MACH_EV2: name = "e2c+"; break;
+    case E2K_MACH_EV3: name = "e2s"; break;
+    case E2K_MACH_1CPLUS:
+    case E2K_MACH_8C:
+    case E2K_MACH_EV4: name = "e8c"; break;
+    case E2K_MACH_EV5: name = "e8c2"; break;
+    case E2K_MACH_EV6: name = "e16c"; break;
+    }
+
+    return name;
+}

linux-user/e2k/target_elf.h

@@ -1,7 +1,27 @@
 #ifndef E2K_TARGET_ELF_H
 #define E2K_TARGET_ELF_H
-static inline const char *cpu_get_model(uint32_t eflags)
-{
-    return "any";
-}
+
+#define E2K_ELF_IPD_MASK  ((1U << 1)|(1U << 0))
+#define E2K_ELF_X86APP    (1U << 2)
+#define E2K_ELF_4MB_PAGES (1U << 3)
+#define E2K_ELF_INCOMPAT  (1U << 4)
+#define E2K_ELF_PM        (1U << 5)
+
+#define E2K_ELF_OLD_MACH(x) (((x) >> 28) & 7)
+#define E2K_ELF_MACH(x)     (((x) >> 24) & 255)
+
+#define E2K_MACH_BASE 0
+#define E2K_MACH_EV1  1
+#define E2K_MACH_EV2  2
+#define E2K_MACH_EV3  3
+#define E2K_MACH_EV4  4
+#define E2K_MACH_EV5  5
+#define E2K_MACH_EV6  6
+
+/* elbrus-v4 based processors */
+#define E2K_MACH_8C     19
+#define E2K_MACH_1CPLUS 20
+
+const char *cpu_get_model(uint32_t eflags);
+
 #endif /* E2K_TARGET_ELF_H */

target/e2k/cpu.c

@@ -96,37 +96,35 @@ void cpu_e2k_set_id(CPUE2KState *env, unsigned int cpu)
 #define DEFAULT_CPU_MODEL "e8c"
 static const struct e2k_def_t e2k_defs[] = {
     {
-        .name           = "e8c", // default choice
-        .canonical_name = "MCST Elbrus 8C",
-        .gdb_arch       = "elbrus-8c",
-        .isa_version    = 4,
-    },
-    {
-        .name           = "e2c+", // however it may work better
+        .name           = "e2c+", /* however it may work better */
         .canonical_name = "MCST Elbrus 2C+ (Monocube)",
         .gdb_arch       = "elbrus-v2",
         .isa_version    = 2,
     },
-    {
-        .name           = "e8c2",
-        .canonical_name = "MCST Elbrus 8CB",
-        .gdb_arch       = "elbrus-v5",
-        .isa_version    = 5,
-    },
-#if 0 /* for reference, never tested */
     {
         .name           = "e2s",
         .canonical_name = "MCST Elbrus 4C",
         .gdb_arch       = "elbrus-v3",
         .isa_version    = 3,
     },
+    {
+        .name           = "e8c", /* default choice for system */
+        .canonical_name = "MCST Elbrus 8C",
+        .gdb_arch       = "elbrus-8c",
+        .isa_version    = 4,
+    },
+    {
+        .name           = "e8c2",
+        .canonical_name = "MCST Elbrus 8CB",
+        .gdb_arch       = "elbrus-v5",
+        .isa_version    = 5,
+    },
     {
         .name           = "e16c",
         .canonical_name = "MCST Elbrus 16C",
         .gdb_arch       = "elbrus-v6",
         .isa_version    = 6,
     },
-#endif
 };
 
 static inline void cpu_dump_state_br(CPUE2KState *env, FILE *f, int flags)
@@ -217,7 +215,7 @@ static ObjectClass *e2k_cpu_class_by_name(const char *cpu_model)
     if (!strcasecmp(cpu_model, "any")) {
         cpu_model = DEFAULT_CPU_MODEL;
     }
-#endif // CONFIG_USER_ONLY
+#endif
    
     typename = e2k_cpu_type_name(cpu_model);
     oc = object_class_by_name(typename);

target/e2k/cpu.h

@@ -665,6 +665,8 @@ typedef struct {
     uint32_t version;
 
     struct e2k_def_t def;
+
+    uint32_t elf_flags;
 } CPUE2KState;
 
 /**