Find all values of the parameter $m$ such that the equations $x^2 = 2^{|x|} + |x| - y - m = 1 - y^2$ have only one root.
1. We start with the given system of equations:
   \[
   x^2 = 2^{|x|} + |x| - y - m
   \]
   \[
   1 - y^2 = 0
   \]
   From the second equation, we can solve for \( y \):
   \[
   1 - y^2 = 0 \implies y^2 = 1 \implies y = \pm 1
   \]

2. Substitute \( y = 1 \) and \( y = -1 \) into the first equation and analyze each case separately.

3. Case 1: \( y = 1 \)
   \[
   x^2 = 2^{|x|} + |x| - 1 - m
   \]
   We need to find \( m \) such that this equation has only one root.

4. Case 2: \( y = -1 \)
   \[
   x^2 = 2^{|x|} + |x| + 1 - m
   \]
   Similarly, we need to find \( m \) such that this equation has only one root.

5. Note that if \( (x, y) \) is a solution, then \( (-x, y) \) is also a solution due to the symmetry in \( x \). Therefore, we must have \( x = 0 \) to ensure a unique solution.

6. Substitute \( x = 0 \) into the equations:
   \[
   0^2 = 2^{|0|} + |0| - y - m \implies 0 = 1 - y - m
   \]
   \[
   1 - y^2 = 0 \implies y = \pm 1
   \]

7. For \( y = 1 \):
   \[
   0 = 1 - 1 - m \implies m = 0
   \]

8. For \( y = -1 \):
   \[
   0 = 1 + 1 - m \implies m = 2
   \]

9. We need to check these values of \( m \) to ensure they result in only one root.

10. If \( m = 2 \):
    \[
    x^2 = 2^{|x|} + |x| + 1 - 2 \implies x^2 = 2^{|x|} + |x| - 1
    \]
    This equation has solutions \( x = 0 \) and \( x = 1 \), so it does not have a unique solution.

11. If \( m = 0 \):
    \[
    x^2 = 2^{|x|} + |x| - 1
    \]
    For \( x = 0 \):
    \[
    0^2 = 2^0 + 0 - 1 \implies 0 = 1 - 1 \implies 0 = 0
    \]
    For \( x \neq 0 \), we need to check if there are any other solutions. Since \( x^2 \leq |x| \) and \( y \leq 1 \leq 2^{|x|} \), we have:
    \[
    x^2 + y \leq 2^{|x|} + |x|
    \]
    This implies \( x^2 = |x| \) and \( y = 1 = 2^{|x|} \). Therefore, the only solution is \( (0, 1) \).

12. Thus, the only value of \( m \) that results in a unique solution is \( m = 0 \).

The final answer is \( \boxed{ m = 0 } \)