From cc413a39355ed910f22f8f0be5e233c08a0773a0 Mon Sep 17 00:00:00 2001 From: Aurelien Jarno Date: Mon, 12 Aug 2013 21:34:53 +0200 Subject: [PATCH] mips_malta: do not raise exceptions when accessing invalid memory Since commit c658b94f6e8c206c59d02aa6fbac285b86b53d2c, MIPS raises exceptions when accessing invalid memory. This is not the correct behaviour for MIPS Malta Core LV, as the GT-64120A system controller just ignore undecoded access. This feature is used by the Linux kernel to probe for some devices. Emulate the correct behaviour in QEMU by adding an empty slot covering the entire memory space decoded by the GT-64120A. Tested-by: Stefan Weil Signed-off-by: Aurelien Jarno --- default-configs/mips-softmmu.mak | 1 + default-configs/mips64-softmmu.mak | 1 + default-configs/mips64el-softmmu.mak | 1 + default-configs/mipsel-softmmu.mak | 1 + hw/mips/mips_malta.c | 6 ++++++ 5 files changed, 10 insertions(+) diff --git a/default-configs/mips-softmmu.mak b/default-configs/mips-softmmu.mak index 926709ae52..71177efdff 100644 --- a/default-configs/mips-softmmu.mak +++ b/default-configs/mips-softmmu.mak @@ -34,3 +34,4 @@ CONFIG_JAZZ_LED=y CONFIG_MC146818RTC=y CONFIG_VT82C686=y CONFIG_ISA_TESTDEV=y +CONFIG_EMPTY_SLOT=y diff --git a/default-configs/mips64-softmmu.mak b/default-configs/mips64-softmmu.mak index 0ef3f09c77..617301b753 100644 --- a/default-configs/mips64-softmmu.mak +++ b/default-configs/mips64-softmmu.mak @@ -34,3 +34,4 @@ CONFIG_JAZZ_LED=y CONFIG_MC146818RTC=y CONFIG_VT82C686=y CONFIG_ISA_TESTDEV=y +CONFIG_EMPTY_SLOT=y diff --git a/default-configs/mips64el-softmmu.mak b/default-configs/mips64el-softmmu.mak index 60893182b3..317b151361 100644 --- a/default-configs/mips64el-softmmu.mak +++ b/default-configs/mips64el-softmmu.mak @@ -36,3 +36,4 @@ CONFIG_JAZZ_LED=y CONFIG_MC146818RTC=y CONFIG_VT82C686=y CONFIG_ISA_TESTDEV=y +CONFIG_EMPTY_SLOT=y diff --git a/default-configs/mipsel-softmmu.mak b/default-configs/mipsel-softmmu.mak index cd59e2479a..532a9aefbd 100644 --- a/default-configs/mipsel-softmmu.mak +++ b/default-configs/mipsel-softmmu.mak @@ -34,3 +34,4 @@ CONFIG_JAZZ_LED=y CONFIG_MC146818RTC=y CONFIG_VT82C686=y CONFIG_ISA_TESTDEV=y +CONFIG_EMPTY_SLOT=y diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c index 0f5de338fa..f8d064cec3 100644 --- a/hw/mips/mips_malta.c +++ b/hw/mips/mips_malta.c @@ -50,6 +50,7 @@ #include "qemu/host-utils.h" #include "sysemu/qtest.h" #include "qemu/error-report.h" +#include "hw/empty_slot.h" //#define DEBUG_BOARD_INIT @@ -908,6 +909,11 @@ void mips_malta_init(QEMUMachineInitArgs *args) DeviceState *dev = qdev_create(NULL, TYPE_MIPS_MALTA); MaltaState *s = MIPS_MALTA(dev); + /* The whole address space decoded by the GT-64120A doesn't generate + exception when accessing invalid memory. Create an empty slot to + emulate this feature. */ + empty_slot_init(0, 0x20000000); + qdev_init_nofail(dev); /* Make sure the first 3 serial ports are associated with a device. */