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Fixed coding error where some fields in a queued JTAG scan would go 

out of scope before the subsequent running of the JTAG queue.  This
just-so-happened not to be causing a visible problem, but was an
accident waiting to happen.
This commit is contained in:
Greg Savin 2019-04-22 10:43:14 -07:00
parent 5c9bea876e
commit 44dda69577
1 changed files with 24 additions and 25 deletions
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49
src/target/riscv/riscv-013.c
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@ -476,6 +476,8 @@ static dmi_status_t dmi_scan(struct target *target, uint32_t *address_in,
.out_value = out, .out_value = out,
.in_value = in .in_value = in
}; };
uint8_t tunneled_dr_width;
struct scan_field tunneled_dr[4];
if (r->reset_delays_wait >= 0) { if (r->reset_delays_wait >= 0) {
r->reset_delays_wait--; r->reset_delays_wait--;
@ -502,32 +504,29 @@ static dmi_status_t dmi_scan(struct target *target, uint32_t *address_in,
if (bscan_tunnel_ir_width != 0) { if (bscan_tunnel_ir_width != 0) {
jtag_add_ir_scan(target->tap, &select_user4, TAP_IDLE); jtag_add_ir_scan(target->tap, &select_user4, TAP_IDLE);
uint8_t tunneled_dr_width = num_bits; /* I wanted to use struct initialization syntax, but that would involve either
declaring the variable within this scope (which would go out of scope at runtime
before the JTAG queue gets executed, which is an error waiting to happen), or
initializing outside of the check for whether a BSCAN tunnel was active (which
would be a waste of CPU time when BSCAN tunnel is not being used. So I declared the
struct at the function's top-level, so it's lifetime exceeds the point at which
the queue is executed, and initializing with assignments here. */
memset(tunneled_dr, 0, sizeof(tunneled_dr));
tunneled_dr[0].num_bits = 1;
tunneled_dr[0].out_value = bscan_one;
struct scan_field tunneled_dr[] = { tunneled_dr[1].num_bits = 7;
{ tunneled_dr_width = num_bits;
.num_bits = 1, tunneled_dr[1].out_value = &tunneled_dr_width;
.out_value = bscan_one,
.in_value = NULL, /* for BSCAN tunnel, there is a one-TCK skew between shift in and shift out, so
}, scanning num_bits + 1, and then will right shift the input field after executing the queues */
{ tunneled_dr[2].num_bits = num_bits+1;
.num_bits = 7, tunneled_dr[2].out_value = out;
.out_value = &tunneled_dr_width, tunneled_dr[2].in_value = in;
.in_value = NULL,
}, tunneled_dr[3].num_bits = 3;
/* for BSCAN tunnel, there is a one-TCK skew between shift in and shift out, so tunneled_dr[3].out_value = bscan_zero;
scanning num_bits + 1, and then will right shift the input field after executing the queues */
{
.num_bits = num_bits+1,
.out_value = out,
.in_value = in,
},
{
.num_bits = 3,
.out_value = bscan_zero,
.in_value = NULL,
}
};
jtag_add_dr_scan(target->tap, DIM(tunneled_dr), tunneled_dr, TAP_IDLE); jtag_add_dr_scan(target->tap, DIM(tunneled_dr), tunneled_dr, TAP_IDLE);
} else { } else {