On 11/4/21 11:19 PM, Warner Losh wrote:
+/* Compare to arm/arm/exec_machdep.c set_mcontext() */
+abi_long set_mcontext(CPUARMState *env, target_mcontext_t *mcp, int srflag)
+{
+ int err = 0;
+ const uint32_t *gr = mcp->__gregs;
+ uint32_t cpsr, ccpsr = cpsr_read(env);
+ uint32_t fpscr, mask;
+
+ cpsr = tswap32(gr[TARGET_REG_CPSR]);
+ /*
+ * Only allow certain bits to change, reject attempted changes to non-user
+ * bits. In addition, make sure we're headed for user mode and none of the
+ * interrupt bits are set.
+ */
+ if ((ccpsr & ~CPSR_USER) != (cpsr & ~CPSR_USER)) {
+ return -TARGET_EINVAL;
+ }
+ if ((cpsr & CPSR_M) != ARM_CPU_MODE_USR ||
+ (cpsr & (CPSR_I | CPSR_F)) != 0) {
+ return -TARGET_EINVAL;
+ }
+ mask = cpsr & CPSR_T ? 0x1 : 0x3;
Should add a sentence or so here, pointing to the exception return instruction used by the
freebsd kernel, which does this masking.
+ /*
+ * Make sure T mode matches the PC's notion of thumb mode, although
+ * FreeBSD lets the processor sort this out, so we may need remove
+ * this check, or generate a signal...
+ */
+ if (!!(tswap32(gr[TARGET_REG_PC]) & 1) != !!(cpsr & CPSR_T)) {
+ return -TARGET_EINVAL;
+ }
Remove this.
+ env->regs[15] = tswap32(gr[TARGET_REG_PC] & mask);
You wanted ~mask.
r~
