Re: [PATCH v2] hw/loongarch: virt: support up to 4 serial ports

[Jason A. Donenfeld]

On Sat, Sep 07, 2024 at 11:37:09AM +0800, maobibo wrote:
> Hi Jason,
> 
> It works well with ELF kernel, however it fails to boot with UEFI BIOS. 
> Maybe it is problem of UEFI BIOS, can we create UART in reverse order? 
> so that it can work well on both ELF kernel and UEFI BIOS.
> 
> Also for develops they usually use as earlycon with command line 
> -serial stdio --append "... earlycon=uart,mmio,0x1fe001e0", this 
> requires to uart with address 0x1fe001e0 as the first serial port.
> 
> Just small code base your patch like this:
> 
> -    for (i = 0; i < VIRT_UART_COUNT; ++i) {
> +    for (i = VIRT_UART_COUNT - 1; i >= 0; i--) {
>           hwaddr base = VIRT_UART_BASE + i * VIRT_UART_SIZE;
>           int irq = VIRT_UART_IRQ + i - VIRT_GSI_BASE;
>           serial_mm_init(get_system_memory(), base, 0,
>                          qdev_get_gpio_in(pch_pic, irq),
> -                       115200, serial_hd(VIRT_UART_COUNT - 1 - i),
> +                       115200, serial_hd(i),
>                          DEVICE_LITTLE_ENDIAN);
> -        fdt_add_uart_node(lvms, pch_pic_phandle, base, irq, i == 
> VIRT_UART_COUNT - 1 - i);
> +        fdt_add_uart_node(lvms, pch_pic_phandle, base, irq, i == 0);
>       }

Fixed: 20240907143439.2792924-1-Jason@zx2c4.com/">https://lore.kernel.org/all/20240907143439.2792924-1-Jason@zx2c4.com/