JTAG: jtag_tap_init() bugfixes

Stop allocating three bytes per IR bit, and cope somewhat better
with IR lengths over 32 bits.

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

diff --git a/src/jtag/core.c b/src/jtag/core.c
index 7c85839b0ae4fe4576145c3ebdfd8a2ff700e2b3..08cfe436b236a41b94a009ef2a72b3abc6bfc404 100644 (file)
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -1204,20 +1204,29 @@ done:
 
 void jtag_tap_init(jtag_tap_t *tap)
 {
+       unsigned ir_len_bits;
+       unsigned ir_len_bytes;
+
        assert(0 != tap->ir_length);
 
-       /// @todo fix, this allocates one byte per bit for all three fields!
-       tap->expected = malloc(tap->ir_length);
-       tap->expected_mask = malloc(tap->ir_length);
-       tap->cur_instr = malloc(tap->ir_length);
+       ir_len_bits = tap->ir_length;
+       ir_len_bytes = CEIL(ir_len_bits, 8);
 
-       /// @todo cope sanely with ir_length bigger than 32 bits
-       buf_set_u32(tap->expected, 0, tap->ir_length, tap->ir_capture_value);
-       buf_set_u32(tap->expected_mask, 0, tap->ir_length, tap->ir_capture_mask);
-       buf_set_ones(tap->cur_instr, tap->ir_length);
+       tap->expected = calloc(1, ir_len_bytes);
+       tap->expected_mask = calloc(1, ir_len_bytes);
+       tap->cur_instr = malloc(ir_len_bytes);
+
+       /// @todo cope better with ir_length bigger than 32 bits
+       if (ir_len_bits > 32)
+               ir_len_bits = 32;
 
-       // place TAP in bypass mode
+       buf_set_u32(tap->expected, 0, ir_len_bits, tap->ir_capture_value);
+       buf_set_u32(tap->expected_mask, 0, ir_len_bits, tap->ir_capture_mask);
+
+       // TAP will be in bypass mode after jtag_validate_ircapture()
        tap->bypass = 1;
+       buf_set_ones(tap->cur_instr, tap->ir_length);
+
        // register the reset callback for the TAP
        jtag_register_event_callback(&jtag_reset_callback, tap);