[Qemu-devel] [PATCH] more auxv entries for x86

[Gwenole Beauchesne]

Hi,

The inlined patch hereunder adds more auxv entries, namely AT_PLATFORM and
AT_HWCAP. This e.g. makes it possible to use Mandriva Linux provided glibc
libraries.

Plain patch available at: 
<http://cvs.mandriva.com/cgi-bin/cvsweb.cgi/contrib-SPECS/qemu/qemu-0.7.2-auxv.patch>

2005-10-23  Gwenole Beauchesne  <address@hidden>

        * linux-user/elfload.c (create_elf_tables): Add AT_PLATFORM and
        AT_HWCAP entries to auxiliary vector.
        * linux-user/main.c (main): setup global_env earlier for elf_exec.

--- qemu/linux-user/elfload.c.auxv      2005-09-05 10:26:06.000000000 +0200
+++ qemu/linux-user/elfload.c   2005-10-24 14:39:20.000000000 +0200
@@ -25,6 +25,26 @@
 
 #ifdef TARGET_I386
 
+#define ELF_PLATFORM get_elf_platform()
+
+static const char *get_elf_platform(void)
+{
+    static char elf_platform[] = "i386";
+    int family = (global_env->cpuid_version >> 8) & 0xff;
+    if (family > 6)
+        family = 6;
+    if (family >= 3)
+        elf_platform[1] = '0' + family;
+    return elf_platform;
+}
+
+#define ELF_HWCAP get_elf_hwcap()
+
+static uint32_t get_elf_hwcap(void)
+{
+  return global_env->cpuid_features;
+}
+
 #define ELF_START_MMAP 0x80000000
 
 /*
@@ -211,6 +231,14 @@ static inline void init_thread(struct ta
 
 #endif
 
+#ifndef ELF_PLATFORM
+#define ELF_PLATFORM (NULL)
+#endif
+
+#ifndef ELF_HWCAP
+#define ELF_HWCAP 0
+#endif
+
 #include "elf.h"
 
 /*
@@ -292,7 +320,7 @@ struct exec
 #define INTERPRETER_AOUT 1
 #define INTERPRETER_ELF 2
 
-#define DLINFO_ITEMS 11
+#define DLINFO_ITEMS 12
 
 static inline void memcpy_fromfs(void * to, const void * from, unsigned long n)
 {
@@ -624,14 +652,26 @@ static unsigned int * create_elf_tables(
 {
         target_ulong *argv, *envp;
         target_ulong *sp, *csp;
+        target_ulong *u_platform;
+        const char *k_platform;
         int v;
 
        /*
         * Force 16 byte _final_ alignment here for generality.
         */
         sp = (unsigned int *) (~15UL & (unsigned long) p);
+        u_platform = NULL;
+        k_platform = ELF_PLATFORM;
+        if (k_platform) {
+            size_t len = strlen(k_platform) + 1;
+            sp -= len;
+            u_platform = (target_ulong *)sp;
+            __copy_to_user(u_platform, k_platform, len);
+        }
         csp = sp;
         csp -= (DLINFO_ITEMS + 1) * 2;
+        if (k_platform)
+          csp -= 2;
 #ifdef DLINFO_ARCH_ITEMS
        csp -= DLINFO_ARCH_ITEMS*2;
 #endif
@@ -659,6 +699,9 @@ static unsigned int * create_elf_tables(
         NEW_AUX_ENT(AT_EUID, (target_ulong) geteuid());
         NEW_AUX_ENT(AT_GID, (target_ulong) getgid());
         NEW_AUX_ENT(AT_EGID, (target_ulong) getegid());
+        NEW_AUX_ENT(AT_HWCAP, (target_ulong) ELF_HWCAP);
+        if (k_platform)
+            NEW_AUX_ENT(AT_PLATFORM, (target_ulong) u_platform);
 #ifdef ARCH_DLINFO
        /* 
         * ARCH_DLINFO must come last so platform specific code can enforce
--- qemu/linux-user/main.c.auxv 2005-08-07 08:39:17.000000000 +0200
+++ qemu/linux-user/main.c      2005-10-24 14:38:44.000000000 +0200
@@ -1095,6 +1095,7 @@ int main(int argc, char **argv)
     /* NOTE: we need to init the CPU at this stage to get
        qemu_host_page_size */
     env = cpu_init();
+    global_env = env;
     
     if (elf_exec(filename, argv+optind, environ, regs, info) != 0) {
        printf("Error loading %s\n", filename);
@@ -1117,8 +1118,6 @@ int main(int argc, char **argv)
     syscall_init();
     signal_init();
 
-    global_env = env;
-
     /* build Task State */
     memset(ts, 0, sizeof(TaskState));
     env->opaque = ts;