Re: [PATCH 2/2] hw/hppa: Fix booting Linux kernel with initrd

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 8/10/25 15:49, Helge Deller wrote:
> Hi Philippe,
> 
> On 10/8/25 15:43, Philippe Mathieu-Daudé wrote:
>> On 22/1/25 19:09, deller@kernel.org wrote:
>>> From: Helge Deller <deller@gmx.de>
>>>
>>> Commit 20f7b890173b ("hw/hppa: Reset vCPUs calling resettable_reset()")
>>> broke booting the Linux kernel with initrd which may have been provided
>>> on the command line. The problem is, that the mentioned commit zeroes
>>> out initial registers which were preset with addresses for the Linux
>>> kernel and initrd.
>>>
>>> Fix it by adding proper variables which are set shortly before starting
>>> the firmware.
>>>
>>> Signed-off-by: Helge Deller <deller@gmx.de>
>>> Fixes: 20f7b890173b ("hw/hppa: Reset vCPUs calling resettable_reset()")
>>> Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
>>> ---
>>>   hw/hppa/machine.c | 48 +++++++++++++++++++----------------------------
>>>   target/hppa/cpu.h |  4 ++++
>>>   2 files changed, 23 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/hw/hppa/machine.c b/hw/hppa/machine.c
>>> index 4bcc66cd6f..0dd1908214 100644
>>> --- a/hw/hppa/machine.c
>>> +++ b/hw/hppa/machine.c
>>> @@ -356,7 +356,6 @@ static void 
>>> machine_HP_common_init_tail(MachineState *machine, PCIBus *pci_bus,
>>>       uint64_t kernel_entry = 0, kernel_low, kernel_high;
>>>       MemoryRegion *addr_space = get_system_memory();
>>>       MemoryRegion *rom_region;
>>> -    unsigned int smp_cpus = machine->smp.cpus;
>>>       SysBusDevice *s;
>>>       /* SCSI disk setup. */
>>> @@ -482,8 +481,8 @@ static void 
>>> machine_HP_common_init_tail(MachineState *machine, PCIBus *pci_bus,
>>>                         kernel_low, kernel_high, kernel_entry, size / 
>>> KiB);
>>>           if (kernel_cmdline) {
>>> -            cpu[0]->env.gr[24] = 0x4000;
>>> -            pstrcpy_targphys("cmdline", cpu[0]->env.gr[24],
>>> +            cpu[0]->env.cmdline_or_bootorder = 0x4000;
>>> +            pstrcpy_targphys("cmdline", cpu[0]- 
>>> >env.cmdline_or_bootorder,
>>>                                TARGET_PAGE_SIZE, kernel_cmdline);
>>
>> I am a bit confused, here @cmdline_or_bootorder contains the physical
>> address of the kernel command line, ...
> ...
>>>           kernel_entry = machine->boot_config.has_menu ? machine- 
>>> >boot_config.menu : 0;
>>> -        cpu[0]->env.gr[24] = machine->boot_config.order[0];
>>> +        cpu[0]->env.cmdline_or_bootorder = machine- 
>>> >boot_config.order[0];
>>
>> ... but here a char ('c' or 'd'). Both seems different things.
>> Is that expected?
> Yes. That's why this variable is called "cmdline" or "bootorder".
> If kernel and cmdline is given, the bios does not need to follow any 
> bootorder
> (which means: boot kernel from C or D).
> If no kernel/cmdline, this parameter tells the firmare to load bootloader
> from c (harddisc) or d (cdrom).

Ah, now I get the variable name... cmdline is used as hwaddr, and 
bootorder as plain char. OK!