On Thu, Feb 17, 2022 at 06:18:58PM +0000, Peter Maydell wrote: > On Thu, 10 Feb 2022 at 06:46, Stafford Horne <sho...@gmail.com> wrote: > > > > Using the device tree means that qemu can now directly tell > > the kernel what hardware is configured rather than use having > > to maintain and update a separate device tree file. > > > > This patch adds device tree support for the OpenRISC simulator. > > A device tree is built up based on the state of the configure > > openrisc simulator. > > This sounds like it's support for creating a device > tree? Support for loading a device tree would be "the > user passes us a filename of a dtb file". (This is mostly a > quibble about commit message wording.)
Ah, yes I will fix this to say, "adds automatic device tree generation support" .... > > -static void openrisc_load_kernel(ram_addr_t ram_size, > > +static hwaddr openrisc_load_kernel(ram_addr_t ram_size, > > const char *kernel_filename) > > Indentation looks off now ? Fixed now. > > { > > long kernel_size; > > uint64_t elf_entry; > > + uint64_t high_addr; > > hwaddr entry; > > > > if (kernel_filename && !qtest_enabled()) { > > kernel_size = load_elf(kernel_filename, NULL, NULL, NULL, > > - &elf_entry, NULL, NULL, NULL, 1, > > EM_OPENRISC, > > - 1, 0); > > + &elf_entry, NULL, &high_addr, NULL, 1, > > + EM_OPENRISC, 1, 0); > > entry = elf_entry; > > if (kernel_size < 0) { > > kernel_size = load_uimage(kernel_filename, > > &entry, NULL, NULL, NULL, NULL); > > + high_addr = entry + kernel_size; > > } > > if (kernel_size < 0) { > > kernel_size = load_image_targphys(kernel_filename, > > KERNEL_LOAD_ADDR, > > ram_size - KERNEL_LOAD_ADDR); > > + high_addr = KERNEL_LOAD_ADDR + kernel_size; > > } > > > > if (entry <= 0) { > > @@ -168,7 +181,139 @@ static void openrisc_load_kernel(ram_addr_t ram_size, > > exit(1); > > } > > boot_info.bootstrap_pc = entry; > > + > > + return high_addr; > > + } > > + return 0; > > +} > > + > > +static uint32_t openrisc_load_fdt(Or1ksimState *s, hwaddr load_start, > > + uint64_t mem_size) > > Indentation again. Fixed. > > +{ > > + uint32_t fdt_addr; > > + int fdtsize = fdt_totalsize(s->fdt); > > + > > + if (fdtsize <= 0) { > > + error_report("invalid device-tree"); > > + exit(1); > > + } > > + > > + /* We should put fdt right after the kernel */ > > You change this comment in patch 4 -- I think you might as well > just use that text in this patch to start with. OK, I had that at first but I did this to be more techincally correct. I will simplify as you suggest. > > + fdt_addr = ROUND_UP(load_start, 4); > > + > > + fdt_pack(s->fdt); > > fdt_pack() returns an error code -- you should check it. OK. > > + /* copy in the device tree */ > > + qemu_fdt_dumpdtb(s->fdt, fdtsize); > > + > > + rom_add_blob_fixed_as("fdt", s->fdt, fdtsize, fdt_addr, > > + &address_space_memory); > > + > > + return fdt_addr; > > +} > > + > > +static void openrisc_create_fdt(Or1ksimState *s, > > + const struct MemmapEntry *memmap, int num_cpus, uint64_t mem_size, > > + const char *cmdline) > > Indentation. Right, fixed. > > +{ > > + void *fdt; > > + int cpu; > > + char *nodename; > > + int pic_ph; > > + > > + fdt = s->fdt = create_device_tree(&s->fdt_size); > > + if (!fdt) { > > + error_report("create_device_tree() failed"); > > + exit(1); > > + } > > + > > + qemu_fdt_setprop_string(fdt, "/", "compatible", "opencores,or1ksim"); > > + qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x1); > > + qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x1); > > + > > + nodename = g_strdup_printf("/memory@%lx", > > + (long)memmap[OR1KSIM_DRAM].base); > > Use the appropriate format string macro for the type, rather than > casting to long (here and below). Right good point. > > + qemu_fdt_add_subnode(fdt, nodename); > > + qemu_fdt_setprop_cells(fdt, nodename, "reg", > > + memmap[OR1KSIM_DRAM].base, mem_size); > > + qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory"); > > + g_free(nodename); > > + > > + qemu_fdt_add_subnode(fdt, "/cpus"); > > + qemu_fdt_setprop_cell(fdt, "/cpus", "#size-cells", 0x0); > > + qemu_fdt_setprop_cell(fdt, "/cpus", "#address-cells", 0x1); > > + > > + for (cpu = 0; cpu < num_cpus; cpu++) { > > + nodename = g_strdup_printf("/cpus/cpu@%d", cpu); > > + qemu_fdt_add_subnode(fdt, nodename); > > + qemu_fdt_setprop_string(fdt, nodename, "compatible", > > + "opencores,or1200-rtlsvn481"); > > + qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu); > > + qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", > > + OR1KSIM_CLK_MHZ); > > + g_free(nodename); > > + } > > + > > + if (num_cpus > 0) { > > + nodename = g_strdup_printf("/ompic@%lx", > > + (long)memmap[OR1KSIM_OMPIC].base); > > + qemu_fdt_add_subnode(fdt, nodename); > > + qemu_fdt_setprop_string(fdt, nodename, "compatible", > > "openrisc,ompic"); > > + qemu_fdt_setprop_cells(fdt, nodename, "reg", > > + memmap[OR1KSIM_OMPIC].base, > > + memmap[OR1KSIM_OMPIC].size); > > + qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0); > > + qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 0); > > + qemu_fdt_setprop_cell(fdt, nodename, "interrupts", > > OR1KSIM_OMPIC_IRQ); > > + g_free(nodename); > > } > > + > > + nodename = (char *)"/pic"; > > + qemu_fdt_add_subnode(fdt, nodename); > > + pic_ph = qemu_fdt_alloc_phandle(fdt); > > + qemu_fdt_setprop_string(fdt, nodename, "compatible", > > + "opencores,or1k-pic-level"); > > + qemu_fdt_setprop_cell(fdt, nodename, "#interrupt-cells", 1); > > + qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0); > > + qemu_fdt_setprop_cell(fdt, nodename, "phandle", pic_ph); > > + > > + qemu_fdt_setprop_cell(fdt, "/", "interrupt-parent", pic_ph); > > + > > + if (nd_table[0].used) { > > + nodename = g_strdup_printf("/ethoc@%lx", > > + (long)memmap[OR1KSIM_ETHOC].base); > > + qemu_fdt_add_subnode(fdt, nodename); > > + qemu_fdt_setprop_string(fdt, nodename, "compatible", > > "opencores,ethoc"); > > + qemu_fdt_setprop_cells(fdt, nodename, "reg", > > + memmap[OR1KSIM_ETHOC].base, > > + memmap[OR1KSIM_ETHOC].size); > > + qemu_fdt_setprop_cell(fdt, nodename, "interrupts", > > OR1KSIM_ETHOC_IRQ); > > + qemu_fdt_setprop(fdt, nodename, "big-endian", NULL, 0); > > + > > + qemu_fdt_add_subnode(fdt, "/aliases"); > > + qemu_fdt_setprop_string(fdt, "/aliases", "enet0", nodename); > > + g_free(nodename); > > + } > > + > > + nodename = g_strdup_printf("/serial@%lx", > > + (long)memmap[OR1KSIM_UART].base); > > + qemu_fdt_add_subnode(fdt, nodename); > > + qemu_fdt_setprop_string(fdt, nodename, "compatible", "ns16550a"); > > + qemu_fdt_setprop_cells(fdt, nodename, "reg", > > + memmap[OR1KSIM_UART].base, > > + memmap[OR1KSIM_UART].size); > > + qemu_fdt_setprop_cell(fdt, nodename, "interrupts", OR1KSIM_UART_IRQ); > > + qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", > > OR1KSIM_CLK_MHZ); > > + qemu_fdt_setprop(fdt, nodename, "big-endian", NULL, 0); > > + > > + qemu_fdt_add_subnode(fdt, "/chosen"); > > + qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename); > > + if (cmdline) { > > + qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline); > > + } > > + > > + qemu_fdt_setprop_string(fdt, "/aliases", "uart0", nodename); > > I think the pattern the hw/arm/virt.c code uses, where the board > code functions that create the UART, interrupt controller, etc > devices on the board also have the code to add FDT nodes for them. > Especially as the board gets new devices added over time, it's easier > to check that the FDT nodes and the devices match up, and you don't > have to awkwardly duplicate control-flow logic like "we only have > an ethernet device if nd_table[0].used". But I won't insist that > you rewrite this. Right, this makes sense. I might as well split it out. I did it that way for initrd. I it may make sense to do for UART, OMPIC and Ethernet here. > > + g_free(nodename); > > } > > > > static void openrisc_sim_init(MachineState *machine) > > @@ -178,6 +323,7 @@ static void openrisc_sim_init(MachineState *machine) > > OpenRISCCPU *cpus[2] = {}; > > Or1ksimState *s = OR1KSIM_MACHINE(machine); > > MemoryRegion *ram; > > + hwaddr load_addr; > > qemu_irq serial_irq; > > int n; > > unsigned int smp_cpus = machine->smp.cpus; > > @@ -219,7 +365,11 @@ static void openrisc_sim_init(MachineState *machine) > > serial_mm_init(get_system_memory(), or1ksim_memmap[OR1KSIM_UART].base, > > 0, > > serial_irq, 115200, serial_hd(0), DEVICE_NATIVE_ENDIAN); > > > > - openrisc_load_kernel(ram_size, kernel_filename); > > + openrisc_create_fdt(s, or1ksim_memmap, smp_cpus, machine->ram_size, > > + machine->kernel_cmdline); > > + > > + load_addr = openrisc_load_kernel(ram_size, kernel_filename); > > + boot_info.fdt_addr = openrisc_load_fdt(s, load_addr, > > machine->ram_size); > > } > > If the user doesn't specify a kernel file, we'll still load the FDT, > at address zero. Is that sensible/intended behaviour ? Good point, I guess we can add some space to not override the interrupt vectors. The system booting with no kernel will probably not very useful anyway. But I imaging one could connect a debugger and load some binary into memory and having the FDT in memory would be helpful. So moving the fdt offset to 0 + 1-page would give enough space. Does this sound OK? -Stafford