Changeset 70259a55 in mainline for uspace/lib/c/arch/ia64/src/syscall.S

Timestamp:

2018-09-11T21:01:08Z (6 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e38ff16

Parents:

d2c91ab

Message:

ia64: Use appropriate imm21 operand with BREAK

This commit changes the imm21 used with the BREAK instruction to conform
to the IA-64 Software Conventions and Runtime Architecture Guide. This
is necessary to be able to distinguish syscalls from compiler-generated
calls to architected software interrupts (e.g. integer divide by zero).

In order to be able to test the used immediate in break_instruction(),
we extend istate_t to hold the CR.IIM register.

File:

• uspace/lib/c/arch/ia64/src/syscall.S (modified) (1 diff)

uspace/lib/c/arch/ia64/src/syscall.S

@@ -29 +29 @@
 #include <abi/asmtool.h>
 
-/**
- * Immediate operand for break instruction.
- * Be carefull about the value as Ski simulator
- * is somewhat sensitive to its value.
+/*
+ * IA-64 Software Conventions and Runtime Architecture Guide mandates that
+ * the zero-extended imm21 operand of the BREAK instruction is used as follows:
  *
- * 0 will be confused with Ski breakpoint.
- * And higher values will be confused with SSC's.
+ * MSB | Purpose
+ * ----+--------
+ * 000 | Reserved for architected software interrupts
+ * 001 | Available for application use as software interrupts
+ * 01x | Reserved for debugger breakpoints
+ * 1xx | Reserved for definition by each ABI
  */
-#define SYSCALL_IMM     1
+#define SYSCALL_IMM     0x40000
 
 FUNCTION_BEGIN(__syscall)