[Qemu-devel] [RFC PATCH 0/2] hw/char/bcm2835_aux: Provide full 16550 UART support

[Philippe Mathieu-Daudé]

Hi,

Since there has been some activity on the list asking about
Rasberry PI USB support, I had a look a some previous unfinished
work and rebased it to share, in case it helps hobbyist interested
in improving these machines.

This series is some proof-of-concept on improving the AUX UART
support. See the commit description for various TODO/questions.

This can be tested using files documented by Peter Maydell in
his blog post:
https://translatedcode.wordpress.com/2018/04/25/debian-on-qemus-raspberry-pi-3-model/

And using the kernel command line arguments suggested by Guenter Roeck:

qemu-system-aarch64 -M raspi3 -m 1024 \
  -kernel raspi3/bootpart/vmlinuz-4.14.0-3-arm64 \
  -initrd raspi3/bootpart/initrd.img-4.14.0-3-arm64 \
  -dtb raspi3/bootpart/bcm2837-rpi-3-b.dtb \
  -append 'earlycon=uart8250,mmio32,0x3f215040 rdinit=/sbin/init panic=-1 
console=ttyS1,115200' \
  -drive 
file=raspi3/2018-01-08-raspberry-pi-3-buster-PREVIEW.img,format=raw,if=sd \
  -serial null -serial stdio \
  -d unimp,guest_errors -trace bcm283\*
27459@1566304158.228297:bcm2835_sdhost_edm_change (device reset) EDM now 0xc60f
[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 4.14.0-3-arm64 (address@hidden) (gcc version 7.2.0 
(Debian 7.2.0-18)) #1 SMP Debian 4.14.12-2 (2018-01-06)
[    0.000000] Boot CPU: AArch64 Processor [410fd034]
[    0.000000] Machine model: Raspberry Pi 3 Model B
[    0.000000] earlycon: uart8250 at MMIO32 0x000000003f215040 (options '')
[    0.000000] bootconsole [uart8250] enabled
[    0.000000] efi: Getting EFI parameters from FDT:
[    0.000000] efi: UEFI not found.
[    0.000000] cma: Reserved 64 MiB at 0x0000000038000000
[    0.000000] NUMA: No NUMA configuration found
[    0.000000] NUMA: Faking a node at [mem 
0x0000000000000000-0x000000003bffffff]
[    0.000000] NUMA: NODE_DATA [mem 0x37fdf180-0x37fe0c7f]
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000000000000-0x000000003bffffff]
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x000000003bffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000003bffffff]
[    0.000000] random: fast init done
[    0.000000] percpu: Embedded 22 pages/cpu @ffff800037f74000 s51608 r8192 
d30312 u90112
[    0.000000] Detected VIPT I-cache on CPU0
[    0.000000] CPU features: enabling workaround for ARM erratum 845719
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 241920
[    0.000000] Policy zone: DMA
[    0.000000] Kernel command line: earlycon=uart8250,mmio32,0x3f215040 
rdinit=/sbin/init panic=-1 console=ttyS1,115200
[    0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes)
[    0.000000] Memory: 864772K/983040K available (8252K kernel code, 1448K 
rwdata, 2692K rodata, 4480K init, 601K bss, 52732K reserved, 65536K 
cma-reserved)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     modules : 0xffff000000000000 - 0xffff000008000000   (   128 
MB)
[    0.000000]     vmalloc : 0xffff000008000000 - 0xffff7dffbfff0000   (129022 
GB)
[    0.000000]       .text : 0xffff000008080000 - 0xffff000008890000   (  8256 
KB)
[    0.000000]     .rodata : 0xffff000008890000 - 0xffff000008b40000   (  2752 
KB)
[    0.000000]       .init : 0xffff000008b40000 - 0xffff000008fa0000   (  4480 
KB)
[    0.000000]       .data : 0xffff000008fa0000 - 0xffff00000910a200   (  1449 
KB)
[    0.000000]        .bss : 0xffff00000910a200 - 0xffff0000091a0910   (   602 
KB)
[    0.000000]     fixed   : 0xffff7dfffe7fd000 - 0xffff7dfffec00000   (  4108 
KB)
[    0.000000]     PCI I/O : 0xffff7dfffee00000 - 0xffff7dffffe00000   (    16 
MB)
[    0.000000]     vmemmap : 0xffff7e0000000000 - 0xffff800000000000   (  2048 
GB maximum)
[    0.000000]               0xffff7e0000000000 - 0xffff7e0000f00000   (    15 
MB actual)
[    0.000000]     memory  : 0xffff800000000000 - 0xffff80003c000000   (   960 
MB)
[    0.000000] ftrace: allocating 30760 entries in 121 pages
[    0.000000] Hierarchical RCU implementation.
[    0.000000]  RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=4.
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
[    0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
bcm2836_control_write: Bad offset 0
bcm2836_control_write: Bad offset 8
[    0.000000] arch_timer: WARNING: Invalid trigger for IRQ2, assuming level low
[    0.000000] arch_timer: WARNING: Please fix your firmware
[    0.000000] arch_timer: cp15 timer(s) running at 62.50MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff 
max_cycles: 0x1cd42e208c, max_idle_ns: 881590405314 ns
[    0.001154] sched_clock: 56 bits at 62MHz, resolution 16ns, wraps every 
4398046511096ns
[    0.068563] Console: colour dummy device 80x25
[    0.081268] Calibrating delay loop (skipped), value calculated using timer 
frequency.. 125.00 BogoMIPS (lpj=250000)
[    0.083225] pid_max: default: 32768 minimum: 301
[    0.094763] Security Framework initialized
[    0.096254] Yama: disabled by default; enable with sysctl kernel.yama.*
[    0.113385] AppArmor: AppArmor initialized
[    0.127602] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.135573] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
[    0.137705] Mount-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.138861] Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes)
[    0.369415] ASID allocator initialised with 65536 entries
[    0.376083] Hierarchical SRCU implementation.
[    0.437838] EFI services will not be available.
[    0.462860] smp: Bringing up secondary CPUs ...
[    0.487588] Detected VIPT I-cache on CPU1
[    0.490893] arch_timer: WARNING: Invalid trigger for IRQ2, assuming level low
[    0.490944] arch_timer: WARNING: Please fix your firmware
[    0.491388] CPU1: Booted secondary processor [410fd034]
[    0.546624] Detected VIPT I-cache on CPU2
[    0.547535] arch_timer: WARNING: Invalid trigger for IRQ2, assuming level low
[    0.547632] arch_timer: WARNING: Please fix your firmware
[    0.548032] CPU2: Booted secondary processor [410fd034]
[    0.574539] Detected VIPT I-cache on CPU3
[    0.575101] arch_timer: WARNING: Invalid trigger for IRQ2, assuming level low
[    0.575150] arch_timer: WARNING: Please fix your firmware
[    0.575367] CPU3: Booted secondary processor [410fd034]
[    0.578684] smp: Brought up 1 node, 4 CPUs
[    0.584515] SMP: Total of 4 processors activated.
[    0.585656] CPU features: detected feature: 32-bit EL0 Support
[    0.603653] CPU: All CPU(s) started at EL2
[    0.607831] alternatives: patching kernel code
[    0.695440] devtmpfs: initialized
[    0.806025] Registered cp15_barrier emulation handler
[    0.806837] Registered setend emulation handler
[    0.816246] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, 
max_idle_ns: 7645041785100000 ns
[    0.818294] futex hash table entries: 1024 (order: 5, 131072 bytes)
[    0.864640] pinctrl core: initialized pinctrl subsystem
[    0.929209] DMI not present or invalid.
[    0.955714] NET: Registered protocol family 16
[    1.063727] cpuidle: using governor ladder
[    1.068747] cpuidle: using governor menu
[    1.079439] vdso: 2 pages (1 code @ ffff000008896000, 1 data @ 
ffff000008fa5000)
[    1.081031] hw-breakpoint: found 6 breakpoint and 4 watchpoint registers.
[    1.127784] DMA: preallocated 256 KiB pool for atomic allocations
[    1.137470] Serial: AMBA PL011 UART driver
[    1.195277] uart-pl011 3f201000.serial: could not find pctldev for node 
/soc/gpio@7e200000/uart0_gpio32, deferring probe
[    1.398312] HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages
[    1.436505] ACPI: Interpreter disabled.
[    1.461028] vgaarb: loaded
[    1.473307] EDAC MC: Ver: 3.0.0
[    1.481644] dmi: Firmware registration failed.
[    1.543428] clocksource: Switched to clocksource arch_sys_counter
[    2.815434] VFS: Disk quotas dquot_6.6.0
[    2.817156] VFS: Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[    2.850332] AppArmor: AppArmor Filesystem Enabled
[    2.854670] pnp: PnP ACPI: disabled
[    3.035675] NET: Registered protocol family 2
[    3.071712] TCP established hash table entries: 8192 (order: 4, 65536 bytes)
[    3.073599] TCP bind hash table entries: 8192 (order: 5, 131072 bytes)
[    3.075011] TCP: Hash tables configured (established 8192 bind 8192)
[    3.082515] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    3.083954] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    3.094971] NET: Registered protocol family 1
[    3.123313] Unpacking initramfs...

Here it hangs, even with CPRMAN patch from Guenter:
https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg03153.html

Regards,

Phil.

Philippe Mathieu-Daudé (2):
  hw/char/serial: Add a helper to set the divisor register
  hw/char/bcm2835_aux: Provide full 16550 UART support

 hw/arm/bcm2835_peripherals.c  |   2 -
 hw/char/bcm2835_aux.c         | 211 +++-------------------------------
 hw/char/serial.c              |   6 +
 include/hw/char/bcm2835_aux.h |   7 +-
 include/hw/char/serial.h      |   1 +
 5 files changed, 27 insertions(+), 200 deletions(-)

-- 
2.20.1