Method write_reg

pci/src/configuration.rs:652–675

Writes a 32bit register to `reg_idx` in the register map.

(&mut self, reg_idx: usize, value: u32)

    /// Writes a 32bit register to `reg_idx` in the register map.
    pub fn write_reg(&mut self, reg_idx: usize, value: u32) {
        let mut mask = self.writable_bits[reg_idx];

        if (BAR0_REG..BAR0_REG + NUM_BAR_REGS).contains(&reg_idx) {
            // Handle very specific case where the BAR is being written with
            // all 1's to retrieve the BAR size during next BAR reading.
            if value == 0xffff_ffff {
                mask &= self.bars[reg_idx - 4].size;
            }
        } else if reg_idx == ROM_BAR_REG {
            // Handle very specific case where the BAR is being written with
            // all 1's on bits 31-11 to retrieve the BAR size during next BAR
            // reading.
            if value & ROM_BAR_ADDR_MASK == ROM_BAR_ADDR_MASK {
                mask &= self.rom_bar_size;
            }
        }

        if let Some(r) = self.registers.get_mut(reg_idx) {
            *r = (*r & !self.writable_bits[reg_idx]) | (value & mask);
        } else {
            warn!("bad PCI register write {reg_idx}");
        }
    }

    /// Writes a 16bit word to `offset`. `offset` must be 16bit aligned.
    pub fn write_word(&mut self, offset: usize, value: u16) {