Merge remote-tracking branch 'remotes/lalrae/tags/mips-20150626' into staging

MIPS patches 2015-06-26

Changes:
* MIPS UHI semihosting support
* microMIPS32 R6 support

# gpg: Signature made Fri Jun 26 10:42:33 2015 BST using RSA key ID 0B29DA6B
# gpg: Good signature from "Leon Alrae <leon.alrae@imgtec.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8DD3 2F98 5495 9D66 35D4  4FC0 5211 8E3C 0B29 DA6B

* remotes/lalrae/tags/mips-20150626:
  target-mips: add mips32r6-generic CPU definition
  target-mips: microMIPS32 R6 POOL16{A, C} instructions
  target-mips: microMIPS32 R6 Major instructions
  target-mips: microMIPS32 R6 POOL32{I, C} instructions
  target-mips: microMIPS32 R6 POOL32F instructions
  target-mips: microMIPS32 R6 POOL32A{XF} instructions
  target-mips: microMIPS32 R6 branches and jumps
  target-mips: add microMIPS32 R6 opcode enum
  target-mips: signal RI for removed instructions in microMIPS R6
  target-mips: raise RI exceptions when FIR.PS = 0
  target-mips: rearrange gen_compute_compact_branch
  target-mips: refactor {D}LSA, {D}ALIGN, {D}BITSWAP
  target-mips: remove an unused argument
  target-mips: add microMIPS TLBINV, TLBINVF
  target-mips: fix {RD, WR}PGPR in microMIPS
  target-mips: convert host to MIPS errno values when required
  target-mips: add Unified Hosting Interface (UHI) support
  target-mips: remove identical code in different branch
  hw/mips: Do not clear BEV for MIPS malta kernel load
  include/softmmu-semi.h: Make semihosting support 64-bit clean

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 9 insertions, 2 deletions

diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
index 786a8f0638..3082e75340 100644
--- a/hw/mips/mips_malta.c
+++ b/hw/mips/mips_malta.c
@@ -53,6 +53,7 @@
 #include "qemu/error-report.h"
 #include "hw/empty_slot.h"
 #include "sysemu/kvm.h"
+#include "exec/semihost.h"
 
 //#define DEBUG_BOARD_INIT
 
@@ -634,7 +635,13 @@ static void write_bootloader (CPUMIPSState *env, uint8_t *base,
 
     /* Second part of the bootloader */
     p = (uint32_t *) (base + 0x580);
-    stl_p(p++, 0x24040002);                                      /* addiu a0, zero, 2 */
+
+    if (semihosting_get_argc()) {
+        /* Preserve a0 content as arguments have been passed */
+        stl_p(p++, 0x00000000);                         /* nop */
+    } else {
+        stl_p(p++, 0x24040002);                         /* addiu a0, zero, 2 */
+    }
     stl_p(p++, 0x3c1d0000 | (((ENVP_ADDR - 64) >> 16) & 0xffff)); /* lui sp, high(ENVP_ADDR) */
     stl_p(p++, 0x37bd0000 | ((ENVP_ADDR - 64) & 0xffff));        /* ori sp, sp, low(ENVP_ADDR) */
     stl_p(p++, 0x3c050000 | ((ENVP_ADDR >> 16) & 0xffff));       /* lui a1, high(ENVP_ADDR) */
@@ -887,7 +894,7 @@ static void main_cpu_reset(void *opaque)
        read only location. The kernel location and the arguments table
        location does not change. */
     if (loaderparams.kernel_filename) {
-        env->CP0_Status &= ~((1 << CP0St_BEV) | (1 << CP0St_ERL));
+        env->CP0_Status &= ~(1 << CP0St_ERL);
     }
 
     malta_mips_config(cpu);