# HG changeset patch
# User Windel Bouwman
# Date 1424438735 -3600
# Node ID b1daa462ee17a3f42ff28206aaf016c5a26bbe5f
# Parent  f381cea07fec3b8404d71ebc62ec31e9881aa3a6
Made kernel run again

diff -r f381cea07fec -r b1daa462ee17 experiments/qemu_vexpress_a9/run.sh
--- a/experiments/qemu_vexpress_a9/run.sh	Thu Feb 19 14:10:52 2015 +0100
+++ b/experiments/qemu_vexpress_a9/run.sh	Fri Feb 20 14:25:35 2015 +0100
@@ -1,5 +1,7 @@
 #!/bin/bash
 
-qemu-system-arm -M vexpress-a9 -m 128M  -kernel test.bin  \
+MACH=vexpress-a9
+#MACH=realview-pb-a8
+qemu-system-arm -M ${MACH} -m 128M  -kernel test.bin \
     -serial stdio # -nographic
 
diff -r f381cea07fec -r b1daa462ee17 experiments/qemu_vexpress_a9/startup.s
--- a/experiments/qemu_vexpress_a9/startup.s	Thu Feb 19 14:10:52 2015 +0100
+++ b/experiments/qemu_vexpress_a9/startup.s	Fri Feb 20 14:25:35 2015 +0100
@@ -7,15 +7,14 @@
 _start:
  LDR sp, =stack_top
 
- ldr r2, =0x10009000
-
- mov r1, #'1'
- str r1, [r2]
+ldr r2, =0x10009000
+mov r1, #'1'
+str r1, [r2]
 
 // Load TTBR0 and TTBR1
- ldr r0, =kernel_table0
- mcr p15, 0, r0, c2, c0, 1
- mcr p15, 0, r0, c2, c0, 0
+ldr r0, =kernel_table0
+mcr p15, 0, r0, c2, c0, 1
+mcr p15, 0, r0, c2, c0, 0
 
  // Domain 0:
 mov r0, #3
@@ -42,9 +41,8 @@
 */
 
 kernel_table0:
- .long 0x00000000 + 0x402 // 0x00000000 # ; Identity map first 1 MB
- .long 0x10000000 + 0x402 // 0x00100000 # ; second mb mapping to peripherals
-
+ .long 0x00000402 // 0x00000000 # ; Identity map first 1 MB
+ .long 0x10000402 // 0x00100000 # ; second mb mapping to peripherals
  .rept 0x600 - 2
   .long 0x0
  .endr
diff -r f381cea07fec -r b1daa462ee17 kernel/arch/qemu_vexpress/layout.mmap
--- a/kernel/arch/qemu_vexpress/layout.mmap	Thu Feb 19 14:10:52 2015 +0100
+++ b/kernel/arch/qemu_vexpress/layout.mmap	Fri Feb 20 14:25:35 2015 +0100
@@ -1,5 +1,5 @@
 
-MEMORY image LOCATION=0x10000 SIZE=0x10000 {
+MEMORY image LOCATION=0x60010000 SIZE=0x10000 {
     SECTION(reset)
     SECTION(code)
     ALIGN(0x4000)
@@ -8,7 +8,7 @@
     SECTION(ramdisk)
 }
 
-MEMORY ram LOCATION=0x20000 SIZE=0x10000 {
+MEMORY ram LOCATION=0x60020000 SIZE=0x10000 {
     SECTION(data)
 }
 
diff -r f381cea07fec -r b1daa462ee17 kernel/arch/qemu_vexpress/start.asm
--- a/kernel/arch/qemu_vexpress/start.asm	Thu Feb 19 14:10:52 2015 +0100
+++ b/kernel/arch/qemu_vexpress/start.asm	Fri Feb 20 14:25:35 2015 +0100
@@ -19,12 +19,18 @@
 
 ; Setup the memory manager and the stack before entering kernel
 
+; Output an 'A' to indicate aliveness:
+ldr r0, txtA
+ldr r1, DRreg
+str r0, [r1, 0]
+
 ; Setup TTBR1 (translation table base register)
 
-ldr r0, =kernel_table0    ; pseudo instruction which loads the value of the symbol
+
+ldr r0, =kernel_table0    ; Load address of label
 ; -KERNEL_BASE
+mcr p15, 0, r0, c2, c0, 0 ; TTBR0
 mcr p15, 0, r0, c2, c0, 1 ; TTBR1
-mcr p15, 0, r0, c2, c0, 0 ; TTBR0
 
 ; Prepare the TTBCR (translation table base control register)
 mov r0, 0x1  ; TBD: why set this to 1?
@@ -35,14 +41,20 @@
 mov r0, 3
 mcr p15, 0, r0, c3, c0, 0
 
+ldr r0, txtB
+ldr r1, DRreg
+str r0, [r1, 0]
 
 ; Enable the VMSA (Virtual memory system architecture):
 mrc p15, 0, r0, c1, c0, 0
-; TODO:
 mov r1, 0x1
-orr r0, r0, r1 ; TODO: implement orr r0, r0, 1
+orr r0, r0, r1
 mcr p15, 0, r0, c1, c0, 0
 
+ldr r0, txtA
+ldr r1, DRregmapped
+str r0, [r1, 0]
+
 ; Setup stack:
 mov sp, 0x30000
 BL kernel_start  ; Branch to main (this is actually in the interrupt vector)
@@ -74,19 +86,32 @@
 mrc p15, 0, r0, c0, c0, 4
 mov pc, lr
 
+; data:
+txtA:
+dcd 65
+txtB:
+dcd 66
+DRreg:
+dcd 0x10009000
+DRregmapped:
+dcd 0x109000
 
 ; Memory map tables:
 
+; Possibly, we are loaded into highmem at address 0x6000 0000,
+; or it may as well be 0x0000 0000 as an alias.
+; In any case, we must put an alias at 0x6000 0000 virtual.
+
 section mem_tables
 
 kernel_table0:
- dcd 0x00000402 ; Identity map first 1 MB
+ dcd 0x60000402 ; Identity map first 1 MB
  dcd 0x10000402 ; Map to peripheral space 1 MB
  repeat 0x5FE
  dcd 0
  endrepeat
 
- dcd 0x00000402 ; Alias to 0x0
+ dcd 0x60000402 ; Alias to 0x0
 
  repeat 0x9FF
  dcd 0
diff -r f381cea07fec -r b1daa462ee17 run.sh
--- a/run.sh	Thu Feb 19 14:10:52 2015 +0100
+++ b/run.sh	Fri Feb 20 14:25:35 2015 +0100
@@ -3,6 +3,6 @@
 set -e
 
 # -S means halt at start:
-qemu-system-arm -M vexpress-a9 -m 128M -kernel kernel_arm.bin \
+qemu-system-arm -M vexpress-a9 -m 128M -kernel kernel/kernel_arm.bin \
     -serial stdio