arm: fix arm kernel boot for non zero start addr

Booting an arm kernel has been broken a while when booting from non zero start
address. This is due to the order of events: board init loads the kernel and
sets register 15 to the start address and then qemu_system_reset reset the cpu
making register 15 zero again.

This patch fixes the usage of the register 15 start address trick in
combination with arm_load_kernel.

Signed-off-by: Lars Munch <lars@segv.dk>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

hw/arm_boot.c

@@ -187,6 +187,7 @@ static void main_cpu_reset(void *opaque)
             env->regs[15] = info->entry & 0xfffffffe;
             env->thumb = info->entry & 1;
         } else {
+            env->regs[15] = info->loader_start;
             if (old_param) {
                 set_kernel_args_old(info, info->initrd_size,
                                     info->loader_start);

hw/gumstix.c

@@ -74,8 +74,6 @@ static void connex_init(ram_addr_t ram_size,
         exit(1);
     }
 
-    cpu->env->regs[15] = 0x00000000;
-
     /* Interrupt line of NIC is connected to GPIO line 36 */
     smc91c111_init(&nd_table[0], 0x04000300,
                     pxa2xx_gpio_in_get(cpu->gpio)[36]);
@@ -114,8 +112,6 @@ static void verdex_init(ram_addr_t ram_size,
         exit(1);
     }
 
-    cpu->env->regs[15] = 0x00000000;
-
     /* Interrupt line of NIC is connected to GPIO line 99 */
     smc91c111_init(&nd_table[0], 0x04000300,
                     pxa2xx_gpio_in_get(cpu->gpio)[99]);

hw/mainstone.c

@@ -89,9 +89,6 @@ static void mainstone_common_init(ram_addr_t ram_size,
     cpu_register_physical_memory(0, MAINSTONE_ROM,
                     qemu_ram_alloc(MAINSTONE_ROM) | IO_MEM_ROM);
 
-    /* Setup initial (reset) machine state */
-    cpu->env->regs[15] = mainstone_binfo.loader_start;
-
 #ifdef TARGET_WORDS_BIGENDIAN
     be = 1;
 #else

hw/nseries.c

@@ -1016,7 +1016,6 @@ static void n8x0_boot_init(void *opaque)
     n800_dss_init(&s->blizzard);
 
     /* CPU setup */
-    s->cpu->env->regs[15] = s->cpu->env->boot_info->loader_start;
     s->cpu->env->GE = 0x5;
 
     /* If the machine has a slided keyboard, open it */
@@ -1317,11 +1316,6 @@ static void n8x0_init(ram_addr_t ram_size, const char *boot_device,
     if (usb_enabled)
         n8x0_usb_setup(s);
 
-    /* Setup initial (reset) machine state */
-
-    /* Start at the OneNAND bootloader.  */
-    s->cpu->env->regs[15] = 0;
-
     if (kernel_filename) {
         /* Or at the linux loader.  */
         binfo->kernel_filename = kernel_filename;
@@ -1330,7 +1324,6 @@ static void n8x0_init(ram_addr_t ram_size, const char *boot_device,
         arm_load_kernel(s->cpu->env, binfo);
 
         qemu_register_reset(n8x0_boot_init, s);
-        n8x0_boot_init(s);
     }
 
     if (option_rom[0] && (boot_device[0] == 'n' || !kernel_filename)) {

hw/omap_sx1.c

@@ -195,15 +195,10 @@ static void sx1_init(ram_addr_t ram_size,
 
     /* Load the kernel.  */
     if (kernel_filename) {
-        /* Start at bootloader.  */
-        cpu->env->regs[15] = sx1_binfo.loader_start;
-
         sx1_binfo.kernel_filename = kernel_filename;
         sx1_binfo.kernel_cmdline = kernel_cmdline;
         sx1_binfo.initrd_filename = initrd_filename;
         arm_load_kernel(cpu->env, &sx1_binfo);
-    } else {
-        cpu->env->regs[15] = 0x00000000;
     }
 
     /* TODO: fix next line */

hw/palm.c

@@ -243,7 +243,6 @@ static void palmte_init(ram_addr_t ram_size,
             rom_size = load_image_targphys(option_rom[0], OMAP_CS0_BASE,
                                            flash_size);
             rom_loaded = 1;
-            cpu->env->regs[15] = 0x00000000;
         }
         if (rom_size < 0) {
             fprintf(stderr, "%s: error loading '%s'\n",
@@ -258,9 +257,6 @@ static void palmte_init(ram_addr_t ram_size,
 
     /* Load the kernel.  */
     if (kernel_filename) {
-        /* Start at bootloader.  */
-        cpu->env->regs[15] = palmte_binfo.loader_start;
-
         palmte_binfo.kernel_filename = kernel_filename;
         palmte_binfo.kernel_cmdline = kernel_cmdline;
         palmte_binfo.initrd_filename = initrd_filename;

hw/spitz.c

@@ -993,9 +993,6 @@ static void spitz_common_init(ram_addr_t ram_size,
         /* A 4.0 GB microdrive is permanently sitting in CF slot 0.  */
         spitz_microdrive_attach(cpu, 0);
 
-    /* Setup initial (reset) machine state */
-    cpu->env->regs[15] = spitz_binfo.loader_start;
-
     spitz_binfo.kernel_filename = kernel_filename;
     spitz_binfo.kernel_cmdline = kernel_cmdline;
     spitz_binfo.initrd_filename = initrd_filename;

hw/tosa.c

@@ -229,9 +229,6 @@ static void tosa_init(ram_addr_t ram_size,
 
     tosa_tg_init(cpu);
 
-    /* Setup initial (reset) machine state */
-    cpu->env->regs[15] = tosa_binfo.loader_start;
-
     tosa_binfo.kernel_filename = kernel_filename;
     tosa_binfo.kernel_cmdline = kernel_cmdline;
     tosa_binfo.initrd_filename = initrd_filename;

target-arm/helper.c

@@ -207,7 +207,6 @@ void cpu_reset(CPUARMState *env)
 #else
     /* SVC mode with interrupts disabled.  */
     env->uncached_cpsr = ARM_CPU_MODE_SVC | CPSR_A | CPSR_F | CPSR_I;
-    env->regs[15] = 0;
     /* On ARMv7-M the CPSR_I is the value of the PRIMASK register, and is
        clear at reset.  Initial SP and PC are loaded from ROM.  */
     if (IS_M(env)) {