Re: [Qemu-devel] Running linux on qemu omap

From: Aaro Koskinen
Date: Fri May 24 2019 - 15:02:32 EST


Hi,

On Fri, May 24, 2019 at 06:00:18PM +0300, Aaro Koskinen wrote:
> Please don't delete OMAP boards quite yet :) In the mainline kernel
> they are not orphaned, they frequently get tested using actual hardware,
> and QEMU would help in additional testing. I'll try to get N8x0 boot to
> work with the minimal kernel I use on real HW.

So it was only a matter of attaching the serial console at the QEMU side
(a hackish patch at the end of the mail).

$ qemu-system-arm --version
QEMU emulator version 4.0.0 (v4.0.0-dirty)
Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers
$ qemu-system-arm -M n810 -kernel zImage -nographic
Uncompressing Linux... done, booting the kernel.
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 5.1.0-n8x0_tiny-los_b1ac4+-00007-g7435e73d8ac4 (aaro@amd-fx-6350) (gcc version 8.3.0 (GCC)) #1 Fri May 24 20:43:02 EEST 2019
[ 0.000000] CPU: ARMv6-compatible processor [4107b362] revision 2 (ARMv6TEJ), cr=00c5387d
[ 0.000000] CPU: VIPT aliasing data cache, unknown instruction cache
[ 0.000000] OF: fdt: Machine model: Nokia N810
[ 0.000000] printk: bootconsole [earlycon0] enabled
[ 0.000000] Memory policy: Data cache writeback
[ 0.000000] OMAP2420
[...]

However there are plenty of WARNs that are not present on real hardware.
Anyway, it's a start.

A.

...

diff --git a/hw/arm/nseries.c b/hw/arm/nseries.c
index 906b7ca22d43..52ff83ec5147 100644
--- a/hw/arm/nseries.c
+++ b/hw/arm/nseries.c
@@ -792,6 +792,7 @@ static void n8x0_uart_setup(struct n800_s *s)
qdev_connect_gpio_out(s->mpu->gpio, N8X0_BT_WKUP_GPIO,
csrhci_pins_get(radio)[csrhci_pin_wakeup]);

+ omap_uart_attach(s->mpu->uart[2], serial_hd(0));
omap_uart_attach(s->mpu->uart[BT_UART], radio);
}