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authorPrakash Ramrakhyani <Prakash.Ramrakhyani@arm.com>2011-05-04 20:38:27 -0500
committerPrakash Ramrakhyani <Prakash.Ramrakhyani@arm.com>2011-05-04 20:38:27 -0500
commitf7380052669eb7030e73d4799fb448ffc8e78680 (patch)
tree44f1ec5a6056eca04e1e03876ac2e55dcded9bee
parent307f089e7f67d4a314e95a3f53b721e0971e2183 (diff)
downloadgem5-f7380052669eb7030e73d4799fb448ffc8e78680.tar.xz
ARM: Boot loader changes that make it more flexible about load and I/O addrs
-rw-r--r--system/arm/simple_bootloader/Makefile18
-rw-r--r--system/arm/simple_bootloader/simple.S31
2 files changed, 30 insertions, 19 deletions
diff --git a/system/arm/simple_bootloader/Makefile b/system/arm/simple_bootloader/Makefile
index 43cd88376..098f3724a 100644
--- a/system/arm/simple_bootloader/Makefile
+++ b/system/arm/simple_bootloader/Makefile
@@ -34,25 +34,25 @@
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Authors: Ali Saidi
+# Prakash Ramrakhyani
-# Need to have CROSS_COMPILE set to /path/to/bin/arm-none-eabi-
-# arm-unknown-linux-gnu- might also work
-#
-#
-CROSS_COMPILE=arm-none-eabi-
+# Need to have CROSS_COMPILE set to /path/to/bin/arm-unknown-linux-gnu-
+# or have arm-unknown-linux-gnu in your path
+
+CROSS_COMPILE?=arm-none-linux-gnueabi-
CC=$(CROSS_COMPILE)gcc
CPP=$(CROSS_COMPILE)g++
LD=$(CROSS_COMPILE)ld
-all: boot
+all: boot.arm
-boot.o: boot.S
- $(CC) -mfloat-abi=softfp -march=armv7-a -mfpu=vfpv3 -mthumb -fno-builtin -nostdinc -o boot.o -c boot.S
+boot.o: simple.S
+ $(CC) -mfloat-abi=softfp -march=armv7-a -fno-builtin -nostdinc -o boot.o -c simple.S
boot.arm: boot.o
- $(LD) -o boot.arm -N -Ttext 0 boot.o -non_shared -static
+ $(LD) -o boot.arm -N -Ttext 0x80000000 boot.o -non_shared -static
clean:
diff --git a/system/arm/simple_bootloader/simple.S b/system/arm/simple_bootloader/simple.S
index d8f2905e9..afba47728 100644
--- a/system/arm/simple_bootloader/simple.S
+++ b/system/arm/simple_bootloader/simple.S
@@ -44,7 +44,7 @@
*
* Upon executing this code:
* r0 = 0, r1 = machine number, r2 = atags ptr
- * r3 = kernel start address
+ * r3 = kernel start address, r4 = GIC address, r5 = flag register address
*
* CPU 0 should branch to the kernel start address and it's done with
* the boot loader. Other CPUs need to start in a wfi loop. When CPU0 sends
@@ -56,16 +56,27 @@
.extern main
_start:
_entry:
- mrc p15, 0, r4, c0, c0, 5 // get the MPIDR register
- uxtb r4, r4 // isolate the lower 8 bits (affinity lvl 1)
- adds r4, r4, #0 // set flags for branch
+ b bootldr // All the interrupt vectors jump to the boot loader
+ b bootldr
+ b bootldr
+ b bootldr
+ b bootldr
+ b bootldr
+ b bootldr
+ b bootldr
+ b bootldr
+
+bootldr:
+ mrc p15, 0, r8, c0, c0, 5 // get the MPIDR register
+ uxtb r8, r8 // isolate the lower 8 bits (affinity lvl 1)
+ adds r8, r8, #0 // set flags for branch
bxeq r3 // if it's 0 (CPU 0), branch to kernel
+ mov r8, #1
+ str r8, [r4, #0] // Enable CPU interface on GIC
+ wfi // wait for an interrupt
pen:
- wfi // otherwise wait for an interrupt
- mov r4, #0x30 // Build address of the system controller
- movt r4, #0x1000 // flag register r4 = 0x10000030
- ldr r5, [r4] // load the value
- movs r5, r5 // set the flags on this value
+ ldr r8, [r5] // load the value
+ movs r8, r8 // set the flags on this value
beq pen // if it's zero try again
- bx r5 // Jump to where we've been told
+ bx r8 // Jump to where we've been told
bkpt // We should never get here