/*
* Test low-level exception handling code:
*
* - hook an exception handler
* - clobber (almost) all registers with a known value
* - raise exception
* - from exception handler, increment all saved register
* contents by one (to ensure registers are not only
* saved properly but also restored properly).
* - resume execution
* - verify registers are now 'clobber_value + 1'
*
* NOTE: cannot be used on PSIM because SYS exception is used
* internally by simulator (but we could use a trap or
* something else).
*
* Author: Till Straumann <strauman@slac.stanford.edu>, 2007
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "vectors.h"
typedef struct regs_ {
uint32_t cr, xer, lr, ctr;
uint32_t gpr0;
uint32_t gpr1;
uint32_t gpr2;
uint32_t gpr3;
uint32_t gpr4;
uint32_t gpr5;
uint32_t gpr6;
uint32_t gpr7;
uint32_t gpr8;
uint32_t gpr9;
uint32_t gpr10;
uint32_t gpr11;
uint32_t gpr12;
uint32_t gpr13;
uint32_t gpr14;
uint32_t gpr15;
uint32_t gpr16;
uint32_t gpr17;
uint32_t gpr18;
uint32_t gpr19;
uint32_t gpr20;
uint32_t gpr21;
uint32_t gpr22;
uint32_t gpr23;
uint32_t gpr24;
uint32_t gpr25;
uint32_t gpr26;
uint32_t gpr27;
uint32_t gpr28;
uint32_t gpr29;
uint32_t gpr30;
uint32_t gpr31;
} ppc_exc_int_regs;
#define OFF(x) (uintptr_t)(&((ppc_exc_int_regs*)0)->x)
void
storegs(ppc_exc_int_regs *p0, ppc_exc_int_regs *p1)
{
asm volatile(
" stmw 0, %6(%0) ;"
" mfcr 0 ;"
" stw 0, %2(%0) ;"
" mflr 0 ;"
" stw 0, %3(%0) ;"
" mfxer 0 ;"
" stw 0, %4(%0) ;"
" mfctr 0 ;"
" stw 0, %5(%0) ;"
" lwz 0, %6(%0) ;"
" trap ;"
" stmw 0, %6(%1) ;"
" mfcr 0 ;"
" stw 0, %2(%1) ;"
" mflr 0 ;"
" stw 0, %3(%1) ;"
" mfxer 0 ;"
" stw 0, %4(%1) ;"
" mfctr 0 ;"
" stw 0, %5(%1) ;"
:
:"b"(p0),"b"(p1),
"i"(OFF(cr)), "i"(OFF(lr)), "i"(OFF(xer)), "i"(OFF(ctr)),
"i"(OFF(gpr0))
:"r0");
}
/* Load up all registers from 'pre' issue system call and store
* registers in 'post'
*/
ppc_exc_int_regs pre;
ppc_exc_int_regs pst;
void
clobber()
{
asm volatile(
" lis 2, pre@h ;"
" ori 2, 2, pre@l ;"
" lwz 3, %0(2) ;"
" mtcr 3 ;"
" lwz 3, %1(2) ;"
" mtlr 3 ;"
" lwz 3, %2(2) ;"
" mtxer 3 ;"
/* don't know which ones stick */
" mfxer 3 ;"
" stw 3, %2(2) ;"
" lwz 3, %3(2) ;"
" mtctr 3 ;"
" lwz 0, %4(2) ;"
/* must not clobber R13, R1, R2 */
" stw 13, %6(2) ;"
" lmw 3, %5(2) ;"
" trap ;"
" stmw 0, %4(2) ;"
" mfcr 0 ;"
" stw 0, %0(2) ;"
" mflr 0 ;"
" stw 0, %1(2) ;"
" mfxer 0 ;"
" stw 0, %2(2) ;"
" mfctr 0 ;"
" stw 0, %3(2) ;"
:
:"i"(OFF(cr)), "i"(OFF(lr)), "i"(OFF(xer)), "i"(OFF(ctr)),
"i"(OFF(gpr0)), "i"(OFF(gpr3)), "i"(OFF(gpr13))
:"r0", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9",
"r10", "r11", "r12", "r14", "r15", "r16",
"r17", "r18", "r19", "r20", "r21", "r22", "r23",
"r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
"xer","lr","ctr",
"cr0","cr1","cr2","cr3","cr4","cr5","cr6","cr7",
"memory");
}
typedef union { uint32_t u; uint8_t c[4]; } u32_a_t;
/* exception handler; adds 1 to all register contents (except r1,r2,r13) */
int
handle_clobber_exc(BSP_Exception_frame *f, unsigned vector)
{
int i;
u32_a_t *p = (u32_a_t*)&f->GPR0;
for ( i=0; i<32; i++ ) {
switch (i) {
case 1: case 2: case 13: break;
default:
p[i].u++;
break;
}
}
f->GPR2 = (uint32_t)&pst;
f->EXC_CR++;
f->EXC_CTR++;
f->EXC_XER++;
f->EXC_LR++;
f->EXC_SRR0 += 4;
return 0;
}
/* This routine tests the raw exception code;
* - hook 'handle_clobber_exc' to SYS exception handler
* - clobber all registers with 0xaffe0000 + <index>
* (except: r1, r2, r13, non-sticky bits in xer)
* R2 is clobbered with the address of the pre area.
* - issue 'trap' -> PROG exception
* - exception handler increments all reg. contents by 1,
* stores address of 'pst' area in R2 and returns control
* to ppc_exc_clobber().
* - save all register contents to *R2 (should be &pst).
* - test for mismatches (except R1, R2, R13 and parts of xer)
*/
void
ppc_exc_clobber()
{
u32_a_t *a, *b;
int i;
a = (u32_a_t*)⪯
b = (u32_a_t*)&pst;
for ( i=0; i< sizeof(pre)/sizeof(uint32_t); i++ ) {
a[i].u = 0xaffe0000 + i;
}
ppc_exc_set_handler(ASM_PROG_VECTOR, handle_clobber_exc);
clobber();
ppc_exc_set_handler(ASM_PROG_VECTOR, 0);
for ( i=0; i< sizeof(pre)/sizeof(uint32_t); i++ ) {
switch (i) {
case OFF(gpr1)/sizeof(uint32_t):
case OFF(gpr2)/sizeof(uint32_t):
case OFF(gpr13)/sizeof(uint32_t):
break;
default:
if ( a[i].u != b[i].u - 1 ) {
printf("MISMATCH at %i: 0x%08"PRIx32" -- 0x%08"PRIx32"\n",
i, a[i].u, b[i].u);
}
}
}
}
#if 0
void
ppc_exc_test()
{
ppc_exc_int_regs a, b;
int i;
memset(&a, 0xaa, sizeof(a));
memset(&b, 0x55, sizeof(b));
storegs(&a, &b);
if ( memcmp(&a, &b, sizeof(a)) ) {
printf("FAILURE: context prior and after exception don't match!\n");
}
for ( i=0; i< sizeof(a)/sizeof(uint32_t); i++ ) {
printf("0x%08"PRIx32" -- 0x%08"PRIx32"\n",
((uint32_t __attribute__((may_alias)) *)&a)[i],
((uint32_t __attribute__((may_alias)) *)&b)[i]);
}
}
#endif
