arm_semihosting buildfix

The recent "add armv7m semihosting support" patch introduced two
build errors:

arm_semihosting.c: In function ‘do_semihosting’:
arm_semihosting.c:71: error: ‘spsr’ may be used uninitialized in this function
arm_semihosting.c:71: error: ‘lr’ may be used uninitialized in this function

This fixes those build errors.  The behavior is, however, untested.
(Also, note the two new REVISIT comments.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

diff --git a/src/target/arm_semihosting.c b/src/target/arm_semihosting.c
index 2f50a4a6591a2e6c8d55214a63752eec10e3f415..a247cc88839a4671f7e8bf0eb0d3b6273eed83af 100644 (file)
--- a/src/target/arm_semihosting.c
+++ b/src/target/arm_semihosting.c
@@ -68,16 +68,9 @@ static int do_semihosting(struct target *target)
        struct arm *arm = target_to_arm(target);
        uint32_t r0 = buf_get_u32(arm->core_cache->reg_list[0].value, 0, 32);
        uint32_t r1 = buf_get_u32(arm->core_cache->reg_list[1].value, 0, 32);
-       uint32_t lr, spsr;
        uint8_t params[16];
        int retval, result;
 
-       if (is_arm7_9(target_to_arm7_9(target)))
-       {
-               lr = buf_get_u32(ARMV4_5_CORE_REG_MODE(arm->core_cache, ARM_MODE_SVC, 14).value, 0, 32);
-               spsr = buf_get_u32(arm->spsr->value, 0, 32);;
-       }
-
        /*
         * TODO: lots of security issues are not considered yet, such as:
         * - no validation on target provided file descriptors
@@ -396,22 +389,35 @@ static int do_semihosting(struct target *target)
 
        /* resume execution to the original mode */
 
+       /* REVISIT this looks wrong ... ARM11 and Cortex-A8
+        * should work this way at least sometimes.
+        */
        if (is_arm7_9(target_to_arm7_9(target)))
        {
+               uint32_t spsr;
+
                /* return value in R0 */
                buf_set_u32(arm->core_cache->reg_list[0].value, 0, 32, result);
                arm->core_cache->reg_list[0].dirty = 1;
 
                /* LR --> PC */
-               buf_set_u32(arm->core_cache->reg_list[15].value, 0, 32, lr);
+               buf_set_u32(arm->core_cache->reg_list[15].value, 0, 32,
+                       buf_get_u32(arm_reg_current(arm,14)->value, 0, 32));
                arm->core_cache->reg_list[15].dirty = 1;
 
                /* saved PSR --> current PSR */
+               spsr = buf_get_u32(arm->spsr->value, 0, 32);
+
+               /* REVISIT should this be arm_set_cpsr(arm, spsr)
+                * instead of a partially unrolled version?
+                */
+
                buf_set_u32(arm->cpsr->value, 0, 32, spsr);
                arm->cpsr->dirty = 1;
                arm->core_mode = spsr & 0x1f;
                if (spsr & 0x20)
                        arm->core_state = ARM_STATE_THUMB;
+
        }
        else
        {