arm: factor all exception handlers out of the crt0.S files

Remove the implementations of all exceptions handlers from the
various crt0.S files and have a single implementation in system-arm.h
The new implementation is weak so that it can be overwritten by some
specific code (like the unwinder)

Change-Id: Ib3e041ed6037376bbe0e79286057e1051640dd90
Reviewed-on: http://gerrit.rockbox.org/205
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>

11 files changed, 50 insertions, 312 deletions

diff --git a/firmware/target/arm/crt0.S b/firmware/target/arm/crt0.S
index 7befecb593..b9cc27f5c5 100644
--- a/firmware/target/arm/crt0.S
+++ b/firmware/target/arm/crt0.S
@@ -137,38 +137,6 @@ newstart:
     ldr     ip, =main       @ make sure we are using the virtual address
     bx      ip
 
-/* All illegal exceptions call into UIE with exception address as first
- * parameter. This is calculated differently depending on which exception
- * we're in. Second parameter is exception number, used for a string lookup
- * in UIE. */
-undef_instr_handler:
-    sub    r0, lr, #4   @ r0 points to the faulty ARM instruction
-#ifdef USE_THUMB
-    mrs    r1, spsr
-    tst    r1, #(1<<5)  @ T bit set ?
-    subne  r0, lr, #2   @ if yes, r0 points to the faulty THUMB instruction
-#endif /* USE_THUMB */
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
- * exception being thrown. Make it illegal and call UIE. */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8
-    mov    r1, #2
-    b      UIE
-
 /* Cache-align interrupt stacks */
 .balign    32
 
diff --git a/firmware/target/arm/imx233/crt0.S b/firmware/target/arm/imx233/crt0.S
index 4ae083ccb2..ffc58d56fc 100644
--- a/firmware/target/arm/imx233/crt0.S
+++ b/firmware/target/arm/imx233/crt0.S
@@ -161,38 +161,6 @@ remap:
 1:
     b       1b
 
-/* All illegal exceptions call into UIE with exception address as first
- * parameter. This is calculated differently depending on which exception
- * we're in. Second parameter is exception number, used for a string lookup
- * in UIE. */
-undef_instr_handler:
-    sub    r0, lr, #4   @ r0 points to the faulty ARM instruction
-#ifdef USE_THUMB
-    mrs    r1, spsr
-    tst    r1, #(1<<5)  @ T bit set ?
-    subne  r0, lr, #2   @ if yes, r0 points to the faulty THUMB instruction
-#endif /* USE_THUMB */
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
- * exception being thrown. Make it illegal and call UIE. */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8 
-    mov    r1, #2
-    b      UIE
-
 /* 256 words of IRQ stack */
     .space 256*4
 irq_stack:
diff --git a/firmware/target/arm/imx31/crt0.S b/firmware/target/arm/imx31/crt0.S
index 1c1ae55736..4e489800d4 100644
--- a/firmware/target/arm/imx31/crt0.S
+++ b/firmware/target/arm/imx31/crt0.S
@@ -326,35 +326,6 @@ remap_end:
     .word   0                   @ fiq_handler
 #endif /* BOOTLOADER */
 
-    .text
-
-/* All illegal exceptions call into UIE with exception address as first
- * parameter. This is calculated differently depending on which exception
- * we're in. Second parameter is exception number, used for a string lookup
- * in UIE. */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
- * exception being thrown. Make it illegal and call UIE. */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8
-    mov    r1, #2
-    b      UIE
-
 /* 256 words of IRQ stack */
     .section .bss
     .balign  32
diff --git a/firmware/target/arm/rk27xx/crt0.S b/firmware/target/arm/rk27xx/crt0.S
index 1bbd46a12c..deea0eeaec 100644
--- a/firmware/target/arm/rk27xx/crt0.S
+++ b/firmware/target/arm/rk27xx/crt0.S
@@ -196,30 +196,3 @@ entry_point:
     bhi     1b
 
     bl      main
-
-/* All illegal exceptions call into UIE with exception address as first
- * parameter. This is calculated differently depending on which exception
- * we're in. Second parameter is exception number, used for a string lookup
- * in UIE. */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8 
-    mov    r1, #2
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
- * exception being thrown. Make it illegal and call UIE */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #5
-    b      UIE
diff --git a/firmware/target/arm/s3c2440/crt0.S b/firmware/target/arm/s3c2440/crt0.S
index 8cbd8ab91e..e103f4f49f 100644
--- a/firmware/target/arm/s3c2440/crt0.S
+++ b/firmware/target/arm/s3c2440/crt0.S
@@ -565,35 +565,6 @@ stackmunge:
      */
     b       vectors
 
-/* All illegal exceptions call into UIE with exception address as first
-   parameter. This is calculated differently depending on which exception
-   we're in. Second parameter is exception number, used for a string lookup
-   in UIE.
- */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
-   exception being thrown. Make it illegal and call UIE.
- */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8 
-    mov    r1, #2
-    b      UIE
-
 #if defined(BOOTLOADER)
 fiq_handler:
     b UIE
diff --git a/firmware/target/arm/s5l8700/crt0.S b/firmware/target/arm/s5l8700/crt0.S
index 0582ab0c8f..93bfa8f06c 100644
--- a/firmware/target/arm/s5l8700/crt0.S
+++ b/firmware/target/arm/s5l8700/crt0.S
@@ -507,33 +507,3 @@ start_loc:
 #endif
 
     bl      main
-
-    .text
-/*    .global UIE*/
-
-/* All illegal exceptions call into UIE with exception address as first
- * parameter. This is calculated differently depending on which exception
- * we're in. Second parameter is exception number, used for a string lookup
- * in UIE. */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
- * exception being thrown. Make it illegal and call UIE. */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8 
-    mov    r1, #2
-    b      UIE
diff --git a/firmware/target/arm/s5l8702/crt0.S b/firmware/target/arm/s5l8702/crt0.S
index e894e8f157..563e863a66 100644
--- a/firmware/target/arm/s5l8702/crt0.S
+++ b/firmware/target/arm/s5l8702/crt0.S
@@ -179,33 +179,3 @@ start_loc:
     bhi     1b
 
     bl      main
-
-    .text
-/*    .global UIE*/
-
-/* All illegal exceptions call into UIE with exception address as first
- * parameter. This is calculated differently depending on which exception
- * we're in. Second parameter is exception number, used for a string lookup
- * in UIE. */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
- * exception being thrown. Make it illegal and call UIE. */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8 
-    mov    r1, #2
-    b      UIE
diff --git a/firmware/target/arm/system-arm.c b/firmware/target/arm/system-arm.c
index c4692bbf29..e687e1d82b 100644
--- a/firmware/target/arm/system-arm.c
+++ b/firmware/target/arm/system-arm.c
@@ -36,6 +36,56 @@ static const char* const uiename[] = {
     "SWI"
 };
 
+void __attribute__((weak,naked)) data_abort_handler(void)
+{
+    asm volatile(
+        "sub    r0, lr, #8  \n"
+        "mov    r1, #2      \n"
+        "b      UIE         \n"
+        );
+}
+
+void __attribute__((weak,naked)) software_int_handler(void)
+{
+    asm volatile(
+        "sub    r0, lr, #4  \n"
+        "mov    r1, #4      \n"
+        "b      UIE         \n"
+        );
+}
+
+void __attribute__((weak,naked)) reserved_handler(void)
+{
+    asm volatile(
+        "sub    r0, lr, #4  \n"
+        "mov    r1, #4      \n"
+        "b      UIE         \n"
+        );
+}
+
+void __attribute__((weak,naked)) prefetch_abort_handler(void)
+{
+    asm volatile(
+        "sub    r0, lr, #4  \n"
+        "mov    r1, #1      \n"
+        "b      UIE         \n"
+        );
+}
+
+void __attribute__((weak,naked)) undef_instr_handler(void)
+{
+    asm volatile(
+        "sub    r0, lr, #4    \n"
+#ifdef USE_THUMB
+        "mrs    r1, spsr      \n"
+        "tst    r1, #(1 << 5) \n" // T bit set ?
+        "subne  r0, lr, #2    \n" // if yes, offset to THUMB instruction
+#endif
+        "mov    r1, #0        \n"
+        "b      UIE           \n"
+        );
+}
+
 /* Unexpected Interrupt or Exception handler. Currently only deals with
    exceptions, but will deal with interrupts later.
  */
diff --git a/firmware/target/arm/tcc77x/crt0.S b/firmware/target/arm/tcc77x/crt0.S
index d0873102d4..aebd8974da 100644
--- a/firmware/target/arm/tcc77x/crt0.S
+++ b/firmware/target/arm/tcc77x/crt0.S
@@ -212,35 +212,6 @@ vectors_end:
 
     .text
 
-/* All illegal exceptions call into UIE with exception address as first
-   parameter. This is calculated differently depending on which exception
-   we're in. Second parameter is exception number, used for a string lookup
-   in UIE.
- */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
-   exception being thrown. Make it illegal and call UIE.
- */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8
-    mov    r1, #2
-    b      UIE
-
 irq_handler:
     stmfd  sp!, {r0-r3, r12, lr}
     bl     irq
diff --git a/firmware/target/arm/tcc780x/crt0.S b/firmware/target/arm/tcc780x/crt0.S
index 1dbccf9828..5d271616d0 100644
--- a/firmware/target/arm/tcc780x/crt0.S
+++ b/firmware/target/arm/tcc780x/crt0.S
@@ -282,35 +282,6 @@ vectors_end:
 
     .text
 
-/* All illegal exceptions call into UIE with exception address as first
-   parameter. This is calculated differently depending on which exception
-   we're in. Second parameter is exception number, used for a string lookup
-   in UIE.
- */
-undef_instr_handler:
-    sub    r0, lr, #4
-    mov    r1, #0
-    b      UIE
-
-/* We run sys mode most of the time, and should never see a software
-   exception being thrown. Make it illegal and call UIE.
- */
-software_int_handler:
-reserved_handler:
-    sub    r0, lr, #4
-    mov    r1, #4
-    b      UIE
-
-prefetch_abort_handler:
-    sub    r0, lr, #4
-    mov    r1, #1
-    b      UIE
-
-data_abort_handler:
-    sub    r0, lr, #8
-    mov    r1, #2
-    b      UIE
-
 #ifdef BOOTLOADER
 fiq_handler:
     subs    pc, lr, #4
diff --git a/firmware/target/arm/tms320dm320/crt0.S b/firmware/target/arm/tms320dm320/crt0.S
index d53cff2b63..f1b2eb397c 100644
--- a/firmware/target/arm/tms320dm320/crt0.S
+++ b/firmware/target/arm/tms320dm320/crt0.S
@@ -292,51 +292,6 @@ _delay_cycles:
 .size       _delay_cycles, .-_delay_cycles
 
 /******************************************************************************
- *  Unused exception vectors.  These call the UIE function.                   *
- *  Arguements are:                                                           *
- *      r0: PC of exception                                                   *
- *      r1: Exception number.                                                 *
- *  Exception numbers are as defined:                                         *
- *      0: Undefined Instruction                                              *
- *      1: Prefetch Abort                                                     *
- *      2: Data Abort                                                         *
- *      3: DIV0                                                               *
- *      4: SWI                                                                *
- *  The exceptions return operations are documented in section A2.6 of the    *
- *  ARM Architecture Reference Manual.                                        *
- ******************************************************************************/
-
-/* A2.6.3: Undefined Instruction Exception - LR=PC of next instruction */
-_undefined_instruction:
-    sub    r0, lr, #4
-    mov    r1, #0
-    bl     UIE
-
-/* A2.6.4: Software Interrupt exception - These should not happen in Rockbox,
- * make it illegal
- */
-_software_interrupt:
-    sub    r0, lr, #4
-    mov    r1, #4
-    bl     UIE
-
-/* A2.6.5 Prefetch Abort - This is also the BKPT instruction since this is a
- * v5 target.  Pass it on to UIE since it is not currently used.
- */
-_prefetch_abort:
-    sub    r0, lr, #4
-    mov    r1, #1
-    bl     UIE
-
-/* A2.6.6 Data Abort - There was a memory abort, can return after fixing cause
- * with the LR address.
- */
-_data_abort:
-    sub    r0, lr, #8 
-    mov    r1, #2
-    bl     UIE
-
-/******************************************************************************
  * _dead_loop: Something really unexpected happened (like a reserved          *
  * exception).  Just hang.                                                    *
  ******************************************************************************/