@@ -813,11 +813,26 @@ static long get_file_size(FILE *f)
return size;
}
+/* setup_data types */
+#define SETUP_NONE 0
+#define SETUP_E820_EXT 1
+#define SETUP_DTB 2
+#define SETUP_PCI 3
+#define SETUP_EFI 4
+
+struct setup_data {
+ uint64_t next;
+ uint32_t type;
+ uint32_t len;
+ uint8_t data[0];
+} __attribute__((packed));
+
static void load_linux(PCMachineState *pcms,
FWCfgState *fw_cfg)
{
uint16_t protocol;
int setup_size, kernel_size, initrd_size = 0, cmdline_size;
+ int dtb_size, setup_data_offset;
uint32_t initrd_max;
uint8_t header[8192], *setup, *kernel, *initrd_data;
hwaddr real_addr, prot_addr, cmdline_addr, initrd_addr = 0;
@@ -825,8 +840,10 @@ static void load_linux(PCMachineState *pcms,
char *vmode;
MachineState *machine = MACHINE(pcms);
PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
+ struct setup_data *setup_data;
const char *kernel_filename = machine->kernel_filename;
const char *initrd_filename = machine->initrd_filename;
+ const char *dtb_filename = machine->dtb;
const char *kernel_cmdline = machine->kernel_cmdline;
/* Align to 16 bytes as a paranoia measure */
@@ -989,6 +1006,35 @@ static void load_linux(PCMachineState *pcms,
exit(1);
}
fclose(f);
+
+ /* append dtb to kernel */
+ if (dtb_filename) {
+ if (protocol < 0x209) {
+ fprintf(stderr, "qemu: Linux kernel too old to load a dtb\n");
+ exit(1);
+ }
+
+ dtb_size = get_image_size(dtb_filename);
+ if (dtb_size <= 0) {
+ fprintf(stderr, "qemu: error reading dtb %s: %s\n",
+ dtb_filename, strerror(errno));
+ exit(1);
+ }
+
+ setup_data_offset = QEMU_ALIGN_UP(kernel_size, 16);
+ kernel_size = setup_data_offset + sizeof(struct setup_data) + dtb_size;
+ kernel = g_realloc(kernel, kernel_size);
+
+ stq_p(header+0x250, prot_addr + setup_data_offset);
+
+ setup_data = (struct setup_data *)(kernel + setup_data_offset);
+ setup_data->next = 0;
+ setup_data->type = cpu_to_le32(SETUP_DTB);
+ setup_data->len = cpu_to_le32(dtb_size);
+
+ load_image(dtb_filename, setup_data->data);
+ }
+
memcpy(setup, header, MIN(sizeof(header), setup_size));
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
With "-dtb" on command-line: - append the device tree blob to the kernel image; - pass the blob's pointer to the kernel through setup_data, as requested by upstream kernel commit da6b737b9ab7 ("x86: Add device tree support"). The device tree blob is passed as-is to the guest; none of its fields is modified nor updated. This is not an issue; the kernel commit above uses the device tree only as an extension to the traditional kernel configuration. To: "Michael S. Tsirkin" <mst@redhat.com> To: Paolo Bonzini <pbonzini@redhat.com> To: Richard Henderson <rth@twiddle.net> To: Eduardo Habkost <ehabkost@redhat.com> Cc: qemu-devel@nongnu.org Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> --- Hi, I'm not expert on the x86 memory map at boot and during kernel boot; I found easy to just append the dtb to the kernel image. From my tests this patch is working fine. If you have any hint for a different loading address for dtb, I would be glad to modify this code. Regards, Antonio hw/i386/pc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)