Re: Deprecate the ppc405 boards in QEMU?

[Cédric Le Goater]

On 10/20/21 16:34, Thomas Huth wrote:
> On 20/10/2021 16.31, BALATON Zoltan wrote:
> > On Wed, 20 Oct 2021, LEROY Christophe wrote:
> > > Le 20/10/2021 à 12:10, Cédric Le Goater a écrit :
> > > > I dont understand how
> > > >
> > > >    static bd_t bd;
> > > >
> > > > can be updated in the kernel.
> > >
> > > It's not updated in the kernel.
> > >
> > > It is supposed to be provided by UBoot to Linux Kernel. But modern
> > > kernels don't take that anymore, they take a device tree. For this
> > > reason cuboot takes the content of bd to build/update the device tree.
> > >
> > > Looks like QEMU also provides the bd, see ref405ep_init()
> > >
> > > I managed to get a kernel booting with the following change (and with
> > > CONFIG_ETHERNET removed)
> > >
> > > diff --git a/arch/powerpc/boot/cuboot-hotfoot.c
> > > b/arch/powerpc/boot/cuboot-hotfoot.c
> > > index 888a6b9bfead..63a9545ff55d 100644
> > > --- a/arch/powerpc/boot/cuboot-hotfoot.c
> > > +++ b/arch/powerpc/boot/cuboot-hotfoot.c
> > > @@ -132,6 +132,12 @@ void platform_init(unsigned long r3, unsigned long
> > > r4, unsigned long r5,
> > >                    unsigned long r6, unsigned long r7)
> > >  {
> > >         CUBOOT_INIT();
> > > +        bd.bi_intfreq = 133333333;
> > > +        bd.bi_busfreq = 33333333;
> > > +        bd.bi_procfreq = 133333333;
> > > +        bd.bi_plb_busfreq = 33333333;
> > > +        bd.bi_pci_busfreq = 33333333;
> > > +        bd.bi_opbfreq = 33333333;
> > >         platform_ops.fixups = hotfoot_fixups;
> > >          platform_ops.exit = ibm40x_dbcr_reset;
> > >         fdt_init(_dtb_start);
> >
> > So maybe taihu should also provide this boot info when linux_boot is true (i.e. 
> > using -kernel) like the ref405ep does? Usually when using -kernel without -bios 
> > then QEMU has to also emulate enough of what the firmware would otherwise do 
> > like setting up devices and setting boot environment. Or if we have both -bios 
> > and -kernel then maybe -kernel should tell the firmware to boot a kernel but 
> > that may need a way to do that like setting variables in nvram but we don't 
> > have models of that in taihu. This taihu machine seems to be an early skeleton 
> > that wasn't finished, the ref405ep seems to be more advanced.
>
> I agree, looking code, the ref405ep board seems to be in a better shape than 
> the taihu board. My u-boot image seems to run fine with both machines, so I'd 
> suggest that we deprecate (and later remove) the taihu board, and keep the 
> ref405ep board in QEMU if it is still helpful for Christophe (or anybody else).

Yes. It could nearly run userspace, if one was available.

Thanks,

C.

U-Boot 2015.10-00236-g677f970bc6-dirty (Oct 06 2021 - 08:59:53 +0200)

CPU:   AMCC PowerPC 405EP Rev. B at 770 MHz (PLB=256 OPB=128 EBC=128)
       I2C boot EEPROM disabled
       Internal PCI arbiter enabled
       16 KiB I-Cache 16 KiB D-Cache
Board: Taihu - AMCC PPC405EP Evaluation Board
I2C:   ready
DRAM:  128 MiB
Flash: ## Unknown FLASH on Bank 0 - Size = 0x00000000 = 0 MB
## Unknown FLASH on Bank 1 - Size = 0x00000000 = 0 MB
0 Bytes
*** Warning - bad CRC, using default environment

PCI:   Bus Dev VenId DevId Class Int
PCI:
Net:   No ethernet found.

Type run flash_nfs to mount root filesystem over NFS

Hit any key to stop autoboot:  0
=> bootm 0x1000000
## Booting kernel from Legacy Image at 01000000 ...
   Image Name:   Linux-5.15.0-rc6-dirty
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    3870579 Bytes = 3.7 MiB
   Load Address: 00800000
   Entry Point:  00801ad0
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK
Memory <- <0x0 0x8000000> (128MB)
CPU clock-frequency <- 0x7f28155 (133MHz)
CPU timebase-frequency <- 0x7f28155 (133MHz)
/plb: clock-frequency <- 1fca055 (33MHz)
/plb/opb: clock-frequency <- 1fca055 (33MHz)
/plb/ebc: clock-frequency <- 1fca055 (33MHz)
/plb/opb/serial@ef600300: clock-frequency <- 1d1079 (2MHz)
/plb/opb/serial@ef600400: clock-frequency <- 1d1079 (2MHz)
ethernet0: local-mac-address <- 00:00:00:00:00:00
ethernet1: local-mac-address <- 00:00:2d:e5:44:80
Fixing devtree for 4M Flash

zImage starting: loaded at 0x00800000 (sp: 0x07eaabb0)
Decompression error: 'Not a gzip file'
No valid compressed data found, assume uncompressed data
Allocating 0x73f274 bytes for kernel...
0x71c0f0 bytes of uncompressed data copied

Linux/PowerPC load:
Finalizing device tree... flat tree at 0xf43960
Linux version 5.15.0-rc6-dirty (legoater@yukon) (powerpc64-linux-gnu-gcc (GCC) 
11.2.1 20210728 (Red Hat Cross 11.2.1-1), GNU ld version 2.35.2-1.fc34) #4 Wed 
Oct 20 16:37:46 CEST 2021
Using PowerPC 40x Platform machine description
printk: bootconsole [udbg0] enabled
-----------------------------------------------------
phys_mem_size     = 0x8000000
dcache_bsize      = 0x20
icache_bsize      = 0x20
cpu_features      = 0x0000000000000100
  possible        = 0x0000000000000100
  always          = 0x0000000000000100
cpu_user_features = 0x86000000 0x00000000
mmu_features      = 0x00000004
-----------------------------------------------------
Zone ranges:
  Normal   [mem 0x0000000000000000-0x0000000007ffffff]
Movable zone start for each node
Early memory node ranges
  node   0: [mem 0x0000000000000000-0x0000000007ffffff]
Initmem setup node 0 [mem 0x0000000000000000-0x0000000007ffffff]
MMU: Allocated 1088 bytes of context maps for 255 contexts
Built 1 zonelists, mobility grouping on.  Total pages: 32512
Kernel command line:
Dentry cache hash table entries: 16384 (order: 4, 65536 bytes, linear)
Inode-cache hash table entries: 8192 (order: 3, 32768 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Kernel virtual memory layout:
  * 0xffbdf000..0xfffff000  : fixmap
  * 0xc9000000..0xffbdf000  : vmalloc & ioremap
Memory: 122444K/131072K available (4908K kernel code, 224K rwdata, 1300K 
rodata, 852K init, 136K bss, 8628K reserved, 0K cma-reserved)
SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS: 512, nr_irqs: 512, preallocated irqs: 16
UIC0 (32 IRQ sources) at DCR 0xc0
random: get_random_u32 called from start_kernel+0x498/0x5f8 with crng_init=0
clocksource: timebase: mask: 0xffffffffffffffff max_cycles: 0x1ec031343f, 
max_idle_ns: 440795203544 ns
clocksource: timebase mult[7800000] shift[24] registered
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 
7645041785100000 ns
futex hash table entries: 256 (order: -1, 3072 bytes, linear)
NET: Registered PF_NETLINK/PF_ROUTE protocol family
DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
             
thermal_sys: Registered thermal governor 'step_wise'
PCI host bridge /plb/pci@ec000000 (primary) ranges:
 MEM 0x0000000080000000..0x000000009fffffff -> 0x0000000080000000
  IO 0x00000000e8000000..0x00000000e800ffff -> 0x0000000000000000
4xx PCI DMA offset set to 0x00000000
4xx PCI DMA window base to 0x0000000000000000
DMA window size 0x0000000080000000
PCI: Probing PCI hardware
PCI host bridge to bus 0008:00
pci_bus 0008:00: root bus resource [io  0x0000-0xffff]
pci_bus 0008:00: root bus resource [mem 0x80000000-0x9fffffff]
pci_bus 0008:00: root bus resource [bus 00-ff]
pci_bus 0008:00: busn_res: [bus 00-ff] end is updated to ff
pci_bus 0008:00: busn_res: [bus 00-ff] end is updated to 00
pci_bus 0008:00: resource 4 [io  0x0000-0xffff]
pci_bus 0008:00: resource 5 [mem 0x80000000-0x9fffffff]
vgaarb: loaded
pps_core: LinuxPPS API ver. 1 registered
pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti 
<giometti@linux.it>
PTP clock support registered
clocksource: Switched to clocksource timebase
NET: Registered PF_INET protocol family
IP idents hash table entries: 2048 (order: 2, 16384 bytes, linear)
tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 4096 bytes, linear)
TCP established hash table entries: 1024 (order: 0, 4096 bytes, linear)
TCP bind hash table entries: 1024 (order: 0, 4096 bytes, linear)
TCP: Hash tables configured (established 1024 bind 1024)
UDP hash table entries: 256 (order: 0, 4096 bytes, linear)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes, linear)
NET: Registered PF_UNIX/PF_LOCAL protocol family
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
PCI: CLS 0 bytes, default 32
workingset: timestamp_bits=30 max_order=15 bucket_order=0
io scheduler mq-deadline registered
io scheduler kyber registered
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
printk: console [ttyS0] disabled
serial8250.0: ttyS0 at MMIO 0xef600400 (irq = 16, base_baud = 119047) is a 
16550A
printk: console [ttyS0] enabled
printk: console [ttyS0] enabled
printk: bootconsole [udbg0] disabled
printk: bootconsole [udbg0] disabled
serial8250.0: ttyS1 at MMIO 0xef600300 (irq = 17, base_baud = 119047) is a 
16550A
printk: console [ttyS0] disabled
printk: console [ttyS0] enabled
ef600300.serial: ttyS1 at MMIO 0xef600300 (irq = 17, base_baud = 119047) is a 
16550
brd: module loaded
libphy: Fixed MDIO Bus: probed
NET: Registered PF_INET6 protocol family
Segment Routing with IPv6
In-situ OAM (IOAM) with IPv6
sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
NET: Registered PF_PACKET protocol family
drmem: No dynamic reconfiguration memory found
Freeing unused kernel image (initmem) memory: 852K
Kernel memory protection not selected by kernel config.
Run /init as init process
init[1]: illegal instruction (4) at 10038380 nip 10038380 lr 10034be0 code 1 in 
busybox[10000000+61000]
init[1]: code: 6129c000 7f914840 419d0350 562be13e 380bffff 2b800020 409d0314 
3d204330
init[1]: code: 6c008000 91210018 3d201006 9001001c <c1a9b834> c8010018 fc006828 
fc000018
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
CPU: 0 PID: 1 Comm: init Not tainted 5.15.0-rc6-dirty #4
Call Trace:
[c0815da0] [c0024408] panic+0x11c/0x2e0 (unreliable)
[c0815e00] [c0026038] do_exit+0x8b0/0x908
[c0815e50] [c0027044] do_group_exit+0x34/0x9c
[c0815e70] [c0033bd0] get_signal+0x174/0x734
[c0815ec0] [c0007794] do_notify_resume+0x70/0x2b0
[c0815f20] [c000ca7c] interrupt_exit_user_prepare_main+0x6c/0xe0
[c0815f40] [c000f1e0] interrupt_return+0x14/0x148
--- interrupt: 700 at 0x10038380
NIP:  10038380 LR: 10034be0 CTR: 1000db60
REGS: c0815f50 TRAP: 0700   Not tainted  (5.15.0-rc6-dirty)
MSR:  0008c030 <EE,PR,IR,DR>  CR: 40000024  XER: 00000000

GPR00: 8000005a bf9c7d90 100791f8 000005a4 bf9c8144 0000001f 00000001 1000026c
GPR08: 0000c030 10060000 00001000 0000005b 72656773 00000000 00000000 00000000
GPR16: 00000000 000005b0 00000000 100726ec 00000000 00000000 00000000 00000000
GPR24: 00000000 00000002 00000002 bf9c8144 10070000 000005a4 bf9c8144 000005a4
NIP [10038380] 0x10038380
LR [10034be0] 0x10034be0
--- interrupt: 700
Rebooting in 180 seconds..
QEMU 6.1.50 monitor - type 'help' for more information