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
Signed-off-by: Aditya Gupta <adit...@linux.ibm.com>
---
Changelog
===========
v1:
+ use 'g_file_get_contents' and add check for -append & -dtb as suggested by
Daniel
---
---
hw/ppc/pnv.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 3526852685b4..03600fa62cbd 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -736,10 +736,21 @@ static void pnv_reset(MachineState *machine,
ShutdownCause reason)
}
}
- fdt = pnv_dt_create(machine);
+ if (machine->dtb) {
+ warn_report("with manually passed dtb, some options like '-append'"
+ " will get ignored and the dtb passed will be used as-is");
- /* Pack resulting tree */
- _FDT((fdt_pack(fdt)));
+ /* read the file 'machine->dtb', and load it into 'fdt' buffer */
+ if (!g_file_get_contents(machine->dtb, (gchar **)&fdt, NULL, NULL)) {
+ error_report("Could not load dtb '%s'", machine->dtb);
+ exit(1);
+ }
+ } 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));
@@ -952,6 +963,14 @@ 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);
/*
--
2.45.2
