SECTIONS_MASK
page->flags.f &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
page->flags.f |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
return (mdf.f >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
(SECTIONS_MASK << SECTIONS_PGSHIFT);
(SECTIONS_MASK << SECTIONS_PGSHIFT);