.globl _start
_start:
+ ldr r2, =UART0_PADDR
+ mov r1, #'A'
+ str r1, [r2]
+
ldr r0, =kernel_table0-KERNEL_BASE
mcr p15, 0, r0, c2, c0, 1 @ Set TTBR1 to r0
mcr p15, 0, r0, c2, c0, 0 @ Set TTBR0 to r0 too (for identity)
+ mov r1, #'c'
+ str r1, [r2]
+
mov r0, #1
mcr p15, 0, r0, c2, c0, 2 @ Set TTCR to 1 (50/50 split)
+
+ mov r1, #'e'
+ str r1, [r2]
mov r0, #3
mcr p15, 0, r0, c3, c0, 0 @ Set Domain 0 to Manager
+ mov r1, #'s'
+ str r1, [r2]
+
@ Enable VMSA
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #1
orr r0, r0, #1 << 23
mcr p15, 0, r0, c1, c0, 0
+ ldr r2, =0xF1000000
+ mov r1, #'s'
+ str r1, [r2]
+
+ @ Enable access faults on domains 0 & 1
+ mov r0, #0x55 @ 01010101b
+ mcr p15, 0, r0, c3, c0, 0
+
+ mov r1, #'2'
+ str r1, [r2]
+
@
@ Check for security extensions
@
orreq r0, #0x2000
mcreq p15, 0, r0, c1, c0, 0
+ mov r1, #'-'
+ str r1, [r2]
@ Prepare for interrupts
cps #18 @ IRQ Mode
ldr sp, =abortstack+0x1000
cps #19
- ldr sp, =0x80000000-4 @ Set up stack (top of user range)
+ mov r1, #'a'
+ str r1, [r2]
+ mov r1, #'r'
+ str r1, [r2]
+ mov r1, #'m'
+ str r1, [r2]
+ mov r1, #13
+ str r1, [r2]
+ mov r1, #10
+ str r1, [r2]
+
+.extern bss_start
+.extern bss_size_div_4
+.zero_bss:
+ ldr r0, =bss_start
+ ldr r1, =bss_end
+ mov r3, #0
+.zero_bss_loop:
+ str r3, [r0],#4
+ cmp r0, r1
+ bls .zero_bss_loop
+
+.goto_c:
+ ldr sp, =0x80000000-8 @ Set up stack (top of user range)
ldr r0, =kmain
mov pc, r0
1: b 1b @ Infinite loop
-_ptr_kmain:
- .long kmain
.comm irqstack, 0x1000 @ ; 4KiB Stack
.comm abortstack, 0x1000 @ ; 4KiB Stack
ldr r4, =SyscallHandler
blx r4
+@ ldr r0, =csSyscallPrintRetAddr
+@ ldr r1, [sp,#9*4+5*4]
+@ ldr r4, =Log
+@ blx r4
+
pop {r2} @ errno
pop {r0,r1} @ Ret/RetHi
add sp, #2*4 @ Saved r2/r3
-
+
pop {r4-r12}
rfeia sp! @ Pop state (actually RFEFD)
.arm_specifics:
PUSH_GPRS
- ldr r0, =csIRQ_Tag
- ldr r1, =csIRQ_Fmt
- ldr r4, =Log_Debug
- blx r4
+@ ldr r0, =csIRQ_Tag
+@ ldr r1, =csIRQ_Fmt
+@ ldr r4, =Log_Debug
+@ blx r4
@ Call the registered handler
ldr r0, gpIRQHandler
.globl DataAbort
DataAbort:
sub lr, #8 @ Adjust LR to the correct value
-@ srsdb sp!, #19 @ Switch to supervisor mode (DDI0406B D1.6.5) (actually SRSFD)
+ srsdb sp!, #23 @ Switch to supervisor mode (DDI0406B D1.6.5) (actually SRSFD)
@ cpsid ifa, #19
-@ PUSH_GPRS
+ PUSH_GPRS
- mrc p15, 0, r4, c5, c0, 0 @ Read DFSR (Data Fault Address Register) to stack
- push {r4}
- mrc p15, 0, r3, c6, c0, 0 @ Read DFAR (Data Fault Address Register) into R3
- mov r2, lr
- ldr r1, =csDataAbort_Fmt
- ldr r0, =csAbort_Tag
- ldr r4, =Log_Error
+ mov r3, #0 @ not a prefetch abort
+ mrc p15, 0, r2, c5, c0, 0 @ Read DFSR (Data Fault Status Register) to R2
+ mrc p15, 0, r1, c6, c0, 0 @ Read DFAR (Data Fault Address Register) into R1
+ mov r0, lr @ PC
+ ldr r4, =MM_PageFault
blx r4
- b .
-@ POP_GPRS
-@ rfeia sp! @ Pop state (actually RFEFD)
+ POP_GPRS
+ rfeia sp! @ Pop state (actually RFEFD)
.globl PrefetchAbort
PrefetchAbort:
.asciz "Data Abort - %p accessed %p, DFSR=%x Unk:%x Unk:%x"
csPrefetchAbort_Fmt:
.asciz "Prefetch Abort at %p, IFSR=%x"
+csSyscallPrintRetAddr:
+ .asciz "Syscall ret to %p"
.section .padata
.globl kernel_table0
kernel_table0:
- .long 0x00000002 @ Identity map the first 1 MiB
+ .long 0x00000402 @ Identity map the first 1 MiB
.rept 0x7FC - 1
.long 0
.endr
.long user_table1_map + 0x800 - KERNEL_BASE + 1 @ KStacks
.long user_table1_map + 0xC00 - KERNEL_BASE + 1
@ 0x80000000 - User/Kernel split
- .long 0x00000002 @ Map first 4 MiB to 2GiB
- .long 0x00100002 @
- .long 0x00200002 @
- .long 0x00300002 @
+ .long 0x00000402 @ Map first 4 MiB to 2GiB (KRW only)
+ .long 0x00100402 @
+ .long 0x00200402 @
+ .long 0x00300402 @
.rept 0xF00 - 0x800 - 4
.long 0
.endr
#if PCI_PADDR
- .long PCI_PADDR + 0*(1 << 20) + 2 @ Map PCI config space
- .long PCI_PADDR + 1*(1 << 20) + 2
- .long PCI_PADDR + 2*(1 << 20) + 2
- .long PCI_PADDR + 3*(1 << 20) + 2
- .long PCI_PADDR + 4*(1 << 20) + 2
- .long PCI_PADDR + 5*(1 << 20) + 2
- .long PCI_PADDR + 6*(1 << 20) + 2
- .long PCI_PADDR + 7*(1 << 20) + 2
- .long PCI_PADDR + 8*(1 << 20) + 2
- .long PCI_PADDR + 9*(1 << 20) + 2
- .long PCI_PADDR + 10*(1 << 20) + 2
- .long PCI_PADDR + 11*(1 << 20) + 2
- .long PCI_PADDR + 12*(1 << 20) + 2
- .long PCI_PADDR + 13*(1 << 20) + 2
- .long PCI_PADDR + 14*(1 << 20) + 2
- .long PCI_PADDR + 15*(1 << 20) + 2
+ .long PCI_PADDR + 0*(1 << 20) + 0x402 @ Map PCI config space
+ .long PCI_PADDR + 1*(1 << 20) + 0x402
+ .long PCI_PADDR + 2*(1 << 20) + 0x402
+ .long PCI_PADDR + 3*(1 << 20) + 0x402
+ .long PCI_PADDR + 4*(1 << 20) + 0x402
+ .long PCI_PADDR + 5*(1 << 20) + 0x402
+ .long PCI_PADDR + 6*(1 << 20) + 0x402
+ .long PCI_PADDR + 7*(1 << 20) + 0x402
+ .long PCI_PADDR + 8*(1 << 20) + 0x402
+ .long PCI_PADDR + 9*(1 << 20) + 0x402
+ .long PCI_PADDR + 10*(1 << 20) + 0x402
+ .long PCI_PADDR + 11*(1 << 20) + 0x402
+ .long PCI_PADDR + 12*(1 << 20) + 0x402
+ .long PCI_PADDR + 13*(1 << 20) + 0x402
+ .long PCI_PADDR + 14*(1 << 20) + 0x402
+ .long PCI_PADDR + 15*(1 << 20) + 0x402
#else
.rept 16
.long 0
@ PID0 user table
.globl user_table1_map
@ User table1 data table (only the first half is needed)
-@ - Abused to provide kernel stacks in upper half
+@ - Abused to provide kernel stacks in the unused half of the table
user_table1_map: @ Size = 4KiB (only 2KiB used)
.rept 0x800/4-1
.long 0
.endr
- .long user_table1_map - KERNEL_BASE + 0x10 + 3 @ ...1FF000 = 0x7FDFF000
+ .long user_table1_map - KERNEL_BASE + 0x13 @ ...1FF000 = 0x7FDFF000
@ Kernel stack zone
- .long kernel_table0 + 0x0000 - KERNEL_BASE + 0x10 + 3 @ ...200000 = 0x7FE00000
- .long kernel_table0 + 0x1000 - KERNEL_BASE + 0x10 + 3 @ ...201000 = 0x7FE01000
+ .long kernel_table0 + 0x0000 - KERNEL_BASE + 0x13 @ ...200000 = 0x7FE00000
+ .long kernel_table0 + 0x1000 - KERNEL_BASE + 0x13 @ ...201000 = 0x7FE01000
.rept (0x800/4)-(MM_KSTACK_SIZE/0x1000)-2
.long 0
.endr
#if MM_KSTACK_SIZE != 0x2000
#error Kernel stack size not changed in start.S
#endif
- .long stack + 0x0000 - KERNEL_BASE + 0x10 + 3 @ Kernel Stack
- .long stack + 0x1000 - KERNEL_BASE + 0x10 + 3 @
+ .long stack + 0x0000 - KERNEL_BASE + 0x13 @ Kernel Stack
+ .long stack + 0x1000 - KERNEL_BASE + 0x13 @
.globl kernel_table1_map
kernel_table1_map: @ Size = 4KiB
.rept (0xF00+16)/4
.long 0
.endr
- .long hwmap_table_0 - KERNEL_BASE + (1 << 4) + 3
+ .long hwmap_table_0 - KERNEL_BASE + 0x13
.rept 0xFF8/4 - (0xF00+16)/4 - 1
.long 0
.endr
- .long kernel_table1_map - KERNEL_BASE + (1 << 4) + 3
+ .long kernel_table1_map - KERNEL_BASE + 0x13
.long kernel_exception_map - KERNEL_BASE + 0x13
@ Hardware mappings
.globl hwmap_table_0
hwmap_table_0:
- .long UART0_PADDR + (1 << 4) + 3 @ UART0
+ .long UART0_PADDR + 0x13 @ UART0
.rept 1024 - 1
.long 0
.endr
.rept 256-16
.long 0
.endr
- .long 0x213 @ Map first page for exceptions (Kernel RO)
- .rept 15
+ .long 0x212 @ Map first page for exceptions (Kernel RO, Execute)
+ .rept 16-1-2
.long 0
.endr
+ .long gUsertextPhysStart + 0x22 @ User .text (User RO, Kernel RW, because both is COW)
+ .long 0
.section .padata
stack:
.space MM_KSTACK_SIZE, 0 @ Original kernel stack
+// vim: ts=8, ft=armv7
+