diff options
author | Aditya Gupta <adityag@linux.ibm.com> | 2024-08-20 16:00:03 +0530 |
---|---|---|
committer | Nicholas Piggin <npiggin@gmail.com> | 2024-11-04 09:14:09 +1000 |
commit | 889c5c4c7a32be298aa499a246dbfd0c5fea8a74 (patch) | |
tree | f2250057fd0b2814f3b98fae2530a8d476593356 | |
parent | 6fb6f3096a3c417c8fe1eaaa4e80b230d19ff93d (diff) |
hw/ppc: Implement -dtb support for PowerNV
Currently any device tree passed with -dtb option in QEMU, was ignored
by the PowerNV code.
Read and pass the passed -dtb to the kernel, thus enabling easier
debugging with custom DTBs.
The existing behaviour when -dtb is 'not' passed, is preserved as-is.
But when a '-dtb' is passed, it completely overrides any dtb nodes or
changes QEMU might have done, such as '-append' arguments to the kernel
(which are mentioned in /chosen/bootargs in the dtb), hence add warning
when -dtb is being used
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
-rw-r--r-- | hw/ppc/pnv.c | 51 |
1 files changed, 40 insertions, 11 deletions
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c index 795acc289f..f0f0d7567d 100644 --- a/hw/ppc/pnv.c +++ b/hw/ppc/pnv.c @@ -736,21 +736,27 @@ static void pnv_reset(MachineState *machine, ResetType type) } } - fdt = pnv_dt_create(machine); - - /* Pack resulting tree */ - _FDT((fdt_pack(fdt))); + if (machine->fdt) { + fdt = machine->fdt; + } else { + fdt = pnv_dt_create(machine); + /* Pack resulting tree */ + _FDT((fdt_pack(fdt))); + } qemu_fdt_dumpdtb(fdt, fdt_totalsize(fdt)); cpu_physical_memory_write(PNV_FDT_ADDR, fdt, fdt_totalsize(fdt)); - /* - * Set machine->fdt for 'dumpdtb' QMP/HMP command. Free - * the existing machine->fdt to avoid leaking it during - * a reset. - */ - g_free(machine->fdt); - machine->fdt = fdt; + /* Update machine->fdt with latest fdt */ + if (machine->fdt != fdt) { + /* + * Set machine->fdt for 'dumpdtb' QMP/HMP command. Free + * the existing machine->fdt to avoid leaking it during + * a reset. + */ + g_free(machine->fdt); + machine->fdt = fdt; + } } static ISABus *pnv_chip_power8_isa_create(PnvChip *chip, Error **errp) @@ -952,6 +958,14 @@ static void pnv_init(MachineState *machine) g_free(sz); exit(EXIT_FAILURE); } + + /* checks for invalid option combinations */ + if (machine->dtb && (strlen(machine->kernel_cmdline) != 0)) { + error_report("-append and -dtb cannot be used together, as passed" + " command line is ignored in case of custom dtb"); + exit(EXIT_FAILURE); + } + memory_region_add_subregion(get_system_memory(), 0, machine->ram); /* @@ -1003,6 +1017,21 @@ static void pnv_init(MachineState *machine) } } + /* load dtb if passed */ + if (machine->dtb) { + int fdt_size; + + warn_report("with manually passed dtb, some options like '-append'" + " will get ignored and the dtb passed will be used as-is"); + + /* read the file 'machine->dtb', and load it into 'fdt' buffer */ + machine->fdt = load_device_tree(machine->dtb, &fdt_size); + if (!machine->fdt) { + error_report("Could not load dtb '%s'", machine->dtb); + exit(1); + } + } + /* MSIs are supported on this platform */ msi_nonbroken = true; |