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[newlib-cygwin] arc: Rework default exception handlers for ARC EM and HS
- From: Corinna Vinschen <corinna at sourceware dot org>
- To: newlib-cvs at sourceware dot org
- Date: 25 May 2016 10:16:26 -0000
- Subject: [newlib-cygwin] arc: Rework default exception handlers for ARC EM and HS
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=dd00a8e71935e01062bae711c1e02bcc34baa8a8
commit dd00a8e71935e01062bae711c1e02bcc34baa8a8
Author: Anton Kolesov <Anton.Kolesov@synopsys.com>
Date: Fri May 13 18:09:43 2016 +0300
arc: Rework default exception handlers for ARC EM and HS
Initially crt0.S used a special function, declared as weak as a default
exception handler in interrupt vector table. To let user override individual
handlers, this function had multiple names - one for each IVT entry, which,
however, was terribly confusing for the debugger and user - because it
wasn't clear which symbol will be used as a function name in debugger.
Defining multiple separate functions - one for each handler, would resolve
the mess, but would increase code size of crt0.o.
To clean this up, this patch defines exception handlers as weak symbols as
well, but those are defined as just symbols, not functions, hence there
would be less confusion over what is what. At the same time, users still can
redefine exception handlers symbol by creating functions with respective
names.
libgloss/
2016-05-24 Anton Kolesov <Anton.Kolesov@synopsys.com>
* arc/crt0.S: Convert memory_error and friends to non-function
symbols.
Diff:
---
libgloss/arc/crt0.S | 107 +++++++++++++++++-----------------------------------
1 file changed, 34 insertions(+), 73 deletions(-)
diff --git a/libgloss/arc/crt0.S b/libgloss/arc/crt0.S
index 99c871f..1d966c2 100644
--- a/libgloss/arc/crt0.S
+++ b/libgloss/arc/crt0.S
@@ -61,29 +61,40 @@
#if defined (__ARCEM__) || defined (__ARCHS__)
.section .ivt, "a", @progbits
-; handler's name, type, number,name, offset in IVT (hex/dec)
-.word __start ; exception 0 program entry point 0x0 0
-.word memory_error ; exception 1 memory_error 0x4 4
-.word instruction_error ; exception 2 instruction_error 0x8 8
-.word EV_MachineCheck ; exception 3 EV_MachineCheck 0xC 12
-.word EV_TLBMissI ; exception 4 EV_TLBMissI 0x10 16
-.word EV_TLBMissD ; exception 5 EV_TLBMissD 0x14 20
-.word EV_ProtV ; exception 6 EV_ProtV 0x18 24
-.word EV_PrivilegeV ; exception 7 EV_PrivilegeV 0x1C 28
-.word EV_SWI ; exception 8 EV_SWI 0x20 32
-.word EV_Trap ; exception 9 EV_Trap 0x24 36
-.word EV_Extension ; exception 10 EV_Extension 0x28 40
-.word EV_DivZero ; exception 11 EV_DivZero 0x2C 44
-.word EV_DCError ; exception 12 EV_DCError 0x30 48
-.word EV_Malignedr ; exception 13 EV_Maligned 0x34 52
-.word _exit_halt ; exception 14 unused 0x38 56
-.word _exit_halt ; exception 15 unused 0x3C 60
-.word IRQ_Timer0 ; IRQ 16 Timer 0 0x40 64
-.word IRQ_Timer1 ; IRQ 17 Timer 1 0x44 68
-.word IRQ_18 ; IRQ 18 0x48 72
-.word IRQ_19 ; IRQ 19 0x4C 76
-.word IRQ_20 ; IRQ 20 0x50 80
-
+; Helper macro to define weak symbols to include into interrupt vector table.
+; User code may define those functions in them, so user function will be
+; referenced in the IVT. By default all handlers point to _exit_halt - so they
+; always cause application halt, because if application causes an exception or
+; interrupt, but doesn't set a handler for it - something is wrong in
+; application. Exception is "start" entry of IVT, which points to __start
+; function.
+#define IVT_ENTRY(name) \
+ .word name `\
+ .weak name `\
+ .set name, _exit_halt
+
+; handler's name, number, name, offset in IVT (hex/dec)
+.word __start ; 0 program entry point 0x0 0
+IVT_ENTRY(memory_error) ; 1 memory_error 0x4 4
+IVT_ENTRY(instruction_error) ; 2 instruction_error 0x8 8
+IVT_ENTRY(EV_MachineCheck) ; 3 EV_MachineCheck 0xC 12
+IVT_ENTRY(EV_TLBMissI) ; 4 EV_TLBMissI 0x10 16
+IVT_ENTRY(EV_TLBMissD) ; 5 EV_TLBMissD 0x14 20
+IVT_ENTRY(EV_ProtV) ; 6 EV_ProtV 0x18 24
+IVT_ENTRY(EV_PrivilegeV) ; 7 EV_PrivilegeV 0x1C 28
+IVT_ENTRY(EV_SWI) ; 8 EV_SWI 0x20 32
+IVT_ENTRY(EV_Trap) ; 9 EV_Trap 0x24 36
+IVT_ENTRY(EV_Extension) ; 10 EV_Extension 0x28 40
+IVT_ENTRY(EV_DivZero) ; 11 EV_DivZero 0x2C 44
+IVT_ENTRY(EV_DCError) ; 12 EV_DCError 0x30 48
+IVT_ENTRY(EV_Maligned) ; 13 EV_Maligned 0x34 52
+IVT_ENTRY(EV_Ex14) ; 14 unused 0x38 56
+IVT_ENTRY(EV_Ex15) ; 15 unused 0x3C 60
+IVT_ENTRY(IRQ_Timer0) ; 16 Timer 0 0x40 64
+IVT_ENTRY(IRQ_Timer1) ; 17 Timer 1 0x44 68
+IVT_ENTRY(IRQ_18) ; 18 0x48 72
+IVT_ENTRY(IRQ_19) ; 19 0x4C 76
+IVT_ENTRY(IRQ_20) ; 20 0x50 80
.section .text.__startup, "ax", @progbits
#else
@@ -196,56 +207,6 @@ __start:
; r0 contains exit code
j @exit
-#if defined (__ARCEM__) || defined (__ARCHS__)
-; ARCv2 default interrupt routines, defined as weak symbols.
-; Default implementation halts the core. To conserve code size those symbols
-; share a single implementation, however as a downside debugger and
-; disassembler will not be able to distinguish one from another.
-.weak memory_error
-.weak instruction_error
-.weak EV_MachineCheck
-.weak EV_TLBMissI
-.weak EV_TLBMissD
-.weak EV_ProtV
-.weak EV_PrivilegeV
-.weak EV_SWI
-.weak EV_Trap
-.weak EV_Extension
-.weak EV_DivZero
-.weak EV_DCError
-.weak EV_Malignedr
-.weak IRQ_Timer0
-.weak IRQ_Timer1
-.weak IRQ_18
-.weak IRQ_19
-.weak IRQ_20
-
-.balign 4
-memory_error :
-instruction_error :
-EV_MachineCheck :
-EV_TLBMissI :
-EV_TLBMissD :
-EV_ProtV :
-EV_PrivilegeV :
-EV_SWI :
-EV_Trap :
-EV_Extension :
-EV_DivZero :
-EV_DCError :
-EV_Malignedr :
-IRQ_Timer0 :
-IRQ_Timer1 :
-IRQ_18 :
-IRQ_19 :
-IRQ_20 :
-.Lloop_halt:
- flag 0x01
- nop
- b .Lloop_halt
- nop
-#endif /* __ARCEM__ || __ARCHS__ */
-
.section .text._exit_halt,"ax",@progbits
.global _exit_halt
.type _exit_halt, @function