diff mbox series

[v4] m68k: write bootinfo as rom section and re-randomize on reboot

Message ID 20221017202952.60762-1-Jason@zx2c4.com
State New
Headers show
Series [v4] m68k: write bootinfo as rom section and re-randomize on reboot | expand

Commit Message

Jason A. Donenfeld Oct. 17, 2022, 8:29 p.m. UTC
Rather than poking directly into RAM, add the bootinfo block as a proper
ROM, so that it's restored when rebooting the system. This way, if the
guest corrupts any of the bootinfo items, but then tries to reboot,
it'll still be restored back to normal as expected.

Then, since the RNG seed needs to be fresh on each boot, regenerate the
RNG seed in the ROM when reseting the CPU.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 hw/m68k/bootinfo.h | 48 +++++++++++++++----------------
 hw/m68k/q800.c     | 71 +++++++++++++++++++++++++++++++++-------------
 hw/m68k/virt.c     | 51 +++++++++++++++++++++++----------
 3 files changed, 111 insertions(+), 59 deletions(-)

Comments

Laurent Vivier Oct. 21, 2022, 7:25 p.m. UTC | #1
Le 17/10/2022 à 22:29, Jason A. Donenfeld a écrit :
> Rather than poking directly into RAM, add the bootinfo block as a proper
> ROM, so that it's restored when rebooting the system. This way, if the
> guest corrupts any of the bootinfo items, but then tries to reboot,
> it'll still be restored back to normal as expected.
> 
> Then, since the RNG seed needs to be fresh on each boot, regenerate the
> RNG seed in the ROM when reseting the CPU.
> 
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Laurent Vivier <laurent@vivier.eu>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>   hw/m68k/bootinfo.h | 48 +++++++++++++++----------------
>   hw/m68k/q800.c     | 71 +++++++++++++++++++++++++++++++++-------------
>   hw/m68k/virt.c     | 51 +++++++++++++++++++++++----------
>   3 files changed, 111 insertions(+), 59 deletions(-)

Notes:
- don't send your patch as a reply to a previous version
- add an history:

v4: replace  (void *)(((unsigned long)base + 3) & ~3) by
              (void *)(((uintptr_t)base + 3) & ~3);

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Thanks,
Laurent

> diff --git a/hw/m68k/bootinfo.h b/hw/m68k/bootinfo.h
> index 897162b818..67e6b66b7d 100644
> --- a/hw/m68k/bootinfo.h
> +++ b/hw/m68k/bootinfo.h
> @@ -12,66 +12,66 @@
>   #ifndef HW_M68K_BOOTINFO_H
>   #define HW_M68K_BOOTINFO_H
>   
> -#define BOOTINFO0(as, base, id) \
> +#define BOOTINFO0(base, id) \
>       do { \
> -        stw_phys(as, base, id); \
> +        stw_p(base, id); \
>           base += 2; \
> -        stw_phys(as, base, sizeof(struct bi_record)); \
> +        stw_p(base, sizeof(struct bi_record)); \
>           base += 2; \
>       } while (0)
>   
> -#define BOOTINFO1(as, base, id, value) \
> +#define BOOTINFO1(base, id, value) \
>       do { \
> -        stw_phys(as, base, id); \
> +        stw_p(base, id); \
>           base += 2; \
> -        stw_phys(as, base, sizeof(struct bi_record) + 4); \
> +        stw_p(base, sizeof(struct bi_record) + 4); \
>           base += 2; \
> -        stl_phys(as, base, value); \
> +        stl_p(base, value); \
>           base += 4; \
>       } while (0)
>   
> -#define BOOTINFO2(as, base, id, value1, value2) \
> +#define BOOTINFO2(base, id, value1, value2) \
>       do { \
> -        stw_phys(as, base, id); \
> +        stw_p(base, id); \
>           base += 2; \
> -        stw_phys(as, base, sizeof(struct bi_record) + 8); \
> +        stw_p(base, sizeof(struct bi_record) + 8); \
>           base += 2; \
> -        stl_phys(as, base, value1); \
> +        stl_p(base, value1); \
>           base += 4; \
> -        stl_phys(as, base, value2); \
> +        stl_p(base, value2); \
>           base += 4; \
>       } while (0)
>   
> -#define BOOTINFOSTR(as, base, id, string) \
> +#define BOOTINFOSTR(base, id, string) \
>       do { \
>           int i; \
> -        stw_phys(as, base, id); \
> +        stw_p(base, id); \
>           base += 2; \
> -        stw_phys(as, base, \
> +        stw_p(base, \
>                    (sizeof(struct bi_record) + strlen(string) + \
>                     1 /* null termination */ + 3 /* padding */) & ~3); \
>           base += 2; \
>           for (i = 0; string[i]; i++) { \
> -            stb_phys(as, base++, string[i]); \
> +            stb_p(base++, string[i]); \
>           } \
> -        stb_phys(as, base++, 0); \
> -        base = (base + 3) & ~3; \
> +        stb_p(base++, 0); \
> +        base = (void *)(((uintptr_t)base + 3) & ~3); \
>       } while (0)
>   
> -#define BOOTINFODATA(as, base, id, data, len) \
> +#define BOOTINFODATA(base, id, data, len) \
>       do { \
>           int i; \
> -        stw_phys(as, base, id); \
> +        stw_p(base, id); \
>           base += 2; \
> -        stw_phys(as, base, \
> +        stw_p(base, \
>                    (sizeof(struct bi_record) + len + \
>                     2 /* length field */ + 3 /* padding */) & ~3); \
>           base += 2; \
> -        stw_phys(as, base, len); \
> +        stw_p(base, len); \
>           base += 2; \
>           for (i = 0; i < len; ++i) { \
> -            stb_phys(as, base++, data[i]); \
> +            stb_p(base++, data[i]); \
>           } \
> -        base = (base + 3) & ~3; \
> +        base = (void *)(((uintptr_t)base + 3) & ~3); \
>       } while (0)
>   #endif
> diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
> index a4590c2cb0..e09e244ddc 100644
> --- a/hw/m68k/q800.c
> +++ b/hw/m68k/q800.c
> @@ -321,11 +321,22 @@ static const TypeInfo glue_info = {
>       },
>   };
>   
> +typedef struct {
> +    M68kCPU *cpu;
> +    struct bi_record *rng_seed;
> +} ResetInfo;
> +
>   static void main_cpu_reset(void *opaque)
>   {
> -    M68kCPU *cpu = opaque;
> +    ResetInfo *reset_info = opaque;
> +    M68kCPU *cpu = reset_info->cpu;
>       CPUState *cs = CPU(cpu);
>   
> +    if (reset_info->rng_seed) {
> +        qemu_guest_getrandom_nofail((void *)reset_info->rng_seed->data + 2,
> +            be16_to_cpu(*(uint16_t *)reset_info->rng_seed->data));
> +    }
> +
>       cpu_reset(cs);
>       cpu->env.aregs[7] = ldl_phys(cs->as, 0);
>       cpu->env.pc = ldl_phys(cs->as, 4);
> @@ -386,6 +397,7 @@ static void q800_init(MachineState *machine)
>       NubusBus *nubus;
>       DeviceState *glue;
>       DriveInfo *dinfo;
> +    ResetInfo *reset_info;
>       uint8_t rng_seed[32];
>   
>       linux_boot = (kernel_filename != NULL);
> @@ -396,9 +408,12 @@ static void q800_init(MachineState *machine)
>           exit(1);
>       }
>   
> +    reset_info = g_new0(ResetInfo, 1);
> +
>       /* init CPUs */
>       cpu = M68K_CPU(cpu_create(machine->cpu_type));
> -    qemu_register_reset(main_cpu_reset, cpu);
> +    reset_info->cpu = cpu;
> +    qemu_register_reset(main_cpu_reset, reset_info);
>   
>       /* RAM */
>       memory_region_add_subregion(get_system_memory(), 0, machine->ram);
> @@ -598,6 +613,14 @@ static void q800_init(MachineState *machine)
>       cs = CPU(cpu);
>       if (linux_boot) {
>           uint64_t high;
> +        void *param_blob, *param_ptr, *param_rng_seed;
> +
> +        if (kernel_cmdline) {
> +            param_blob = g_malloc(strlen(kernel_cmdline) + 1024);
> +        } else {
> +            param_blob = g_malloc(1024);
> +        }
> +
>           kernel_size = load_elf(kernel_filename, NULL, NULL, NULL,
>                                  &elf_entry, NULL, &high, NULL, 1,
>                                  EM_68K, 0, 0);
> @@ -607,23 +630,24 @@ static void q800_init(MachineState *machine)
>           }
>           stl_phys(cs->as, 4, elf_entry); /* reset initial PC */
>           parameters_base = (high + 1) & ~1;
> -
> -        BOOTINFO1(cs->as, parameters_base, BI_MACHTYPE, MACH_MAC);
> -        BOOTINFO1(cs->as, parameters_base, BI_FPUTYPE, FPU_68040);
> -        BOOTINFO1(cs->as, parameters_base, BI_MMUTYPE, MMU_68040);
> -        BOOTINFO1(cs->as, parameters_base, BI_CPUTYPE, CPU_68040);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_CPUID, CPUB_68040);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_MODEL, MAC_MODEL_Q800);
> -        BOOTINFO1(cs->as, parameters_base,
> +        param_ptr = param_blob;
> +
> +        BOOTINFO1(param_ptr, BI_MACHTYPE, MACH_MAC);
> +        BOOTINFO1(param_ptr, BI_FPUTYPE, FPU_68040);
> +        BOOTINFO1(param_ptr, BI_MMUTYPE, MMU_68040);
> +        BOOTINFO1(param_ptr, BI_CPUTYPE, CPU_68040);
> +        BOOTINFO1(param_ptr, BI_MAC_CPUID, CPUB_68040);
> +        BOOTINFO1(param_ptr, BI_MAC_MODEL, MAC_MODEL_Q800);
> +        BOOTINFO1(param_ptr,
>                     BI_MAC_MEMSIZE, ram_size >> 20); /* in MB */
> -        BOOTINFO2(cs->as, parameters_base, BI_MEMCHUNK, 0, ram_size);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_VADDR,
> +        BOOTINFO2(param_ptr, BI_MEMCHUNK, 0, ram_size);
> +        BOOTINFO1(param_ptr, BI_MAC_VADDR,
>                     VIDEO_BASE + macfb_mode->offset);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_VDEPTH, graphic_depth);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_VDIM,
> +        BOOTINFO1(param_ptr, BI_MAC_VDEPTH, graphic_depth);
> +        BOOTINFO1(param_ptr, BI_MAC_VDIM,
>                     (graphic_height << 16) | graphic_width);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_VROW, macfb_mode->stride);
> -        BOOTINFO1(cs->as, parameters_base, BI_MAC_SCCBASE, SCC_BASE);
> +        BOOTINFO1(param_ptr, BI_MAC_VROW, macfb_mode->stride);
> +        BOOTINFO1(param_ptr, BI_MAC_SCCBASE, SCC_BASE);
>   
>           rom = g_malloc(sizeof(*rom));
>           memory_region_init_ram_ptr(rom, NULL, "m68k_fake_mac.rom",
> @@ -632,13 +656,14 @@ static void q800_init(MachineState *machine)
>           memory_region_add_subregion(get_system_memory(), MACROM_ADDR, rom);
>   
>           if (kernel_cmdline) {
> -            BOOTINFOSTR(cs->as, parameters_base, BI_COMMAND_LINE,
> +            BOOTINFOSTR(param_ptr, BI_COMMAND_LINE,
>                           kernel_cmdline);
>           }
>   
>           /* Pass seed to RNG. */
> +        param_rng_seed = param_ptr;
>           qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
> -        BOOTINFODATA(cs->as, parameters_base, BI_RNG_SEED,
> +        BOOTINFODATA(param_ptr, BI_RNG_SEED,
>                        rng_seed, sizeof(rng_seed));
>   
>           /* load initrd */
> @@ -653,13 +678,19 @@ static void q800_init(MachineState *machine)
>               initrd_base = (ram_size - initrd_size) & TARGET_PAGE_MASK;
>               load_image_targphys(initrd_filename, initrd_base,
>                                   ram_size - initrd_base);
> -            BOOTINFO2(cs->as, parameters_base, BI_RAMDISK, initrd_base,
> +            BOOTINFO2(param_ptr, BI_RAMDISK, initrd_base,
>                         initrd_size);
>           } else {
>               initrd_base = 0;
>               initrd_size = 0;
>           }
> -        BOOTINFO0(cs->as, parameters_base, BI_LAST);
> +        BOOTINFO0(param_ptr, BI_LAST);
> +        rom_add_blob_fixed_as("bootinfo", param_blob, param_ptr - param_blob,
> +                              parameters_base, cs->as);
> +        reset_info->rng_seed = rom_ptr_for_as(cs->as, parameters_base,
> +                                              param_ptr - param_blob) +
> +                               (param_rng_seed - param_blob);
> +        g_free(param_blob);
>       } else {
>           uint8_t *ptr;
>           /* allocate and load BIOS */
> diff --git a/hw/m68k/virt.c b/hw/m68k/virt.c
> index f7b903ea1b..89c4108eb5 100644
> --- a/hw/m68k/virt.c
> +++ b/hw/m68k/virt.c
> @@ -89,6 +89,7 @@ typedef struct {
>       M68kCPU *cpu;
>       hwaddr initial_pc;
>       hwaddr initial_stack;
> +    struct bi_record *rng_seed;
>   } ResetInfo;
>   
>   static void main_cpu_reset(void *opaque)
> @@ -97,6 +98,11 @@ static void main_cpu_reset(void *opaque)
>       M68kCPU *cpu = reset_info->cpu;
>       CPUState *cs = CPU(cpu);
>   
> +    if (reset_info->rng_seed) {
> +        qemu_guest_getrandom_nofail((void *)reset_info->rng_seed->data + 2,
> +            be16_to_cpu(*(uint16_t *)reset_info->rng_seed->data));
> +    }
> +
>       cpu_reset(cs);
>       cpu->env.aregs[7] = reset_info->initial_stack;
>       cpu->env.pc = reset_info->initial_pc;
> @@ -212,6 +218,13 @@ static void virt_init(MachineState *machine)
>       if (kernel_filename) {
>           CPUState *cs = CPU(cpu);
>           uint64_t high;
> +        void *param_blob, *param_ptr, *param_rng_seed;
> +
> +        if (kernel_cmdline) {
> +            param_blob = g_malloc(strlen(kernel_cmdline) + 1024);
> +        } else {
> +            param_blob = g_malloc(1024);
> +        }
>   
>           kernel_size = load_elf(kernel_filename, NULL, NULL, NULL,
>                                  &elf_entry, NULL, &high, NULL, 1,
> @@ -222,35 +235,37 @@ static void virt_init(MachineState *machine)
>           }
>           reset_info->initial_pc = elf_entry;
>           parameters_base = (high + 1) & ~1;
> +        param_ptr = param_blob;
>   
> -        BOOTINFO1(cs->as, parameters_base, BI_MACHTYPE, MACH_VIRT);
> -        BOOTINFO1(cs->as, parameters_base, BI_FPUTYPE, FPU_68040);
> -        BOOTINFO1(cs->as, parameters_base, BI_MMUTYPE, MMU_68040);
> -        BOOTINFO1(cs->as, parameters_base, BI_CPUTYPE, CPU_68040);
> -        BOOTINFO2(cs->as, parameters_base, BI_MEMCHUNK, 0, ram_size);
> +        BOOTINFO1(param_ptr, BI_MACHTYPE, MACH_VIRT);
> +        BOOTINFO1(param_ptr, BI_FPUTYPE, FPU_68040);
> +        BOOTINFO1(param_ptr, BI_MMUTYPE, MMU_68040);
> +        BOOTINFO1(param_ptr, BI_CPUTYPE, CPU_68040);
> +        BOOTINFO2(param_ptr, BI_MEMCHUNK, 0, ram_size);
>   
> -        BOOTINFO1(cs->as, parameters_base, BI_VIRT_QEMU_VERSION,
> +        BOOTINFO1(param_ptr, BI_VIRT_QEMU_VERSION,
>                     ((QEMU_VERSION_MAJOR << 24) | (QEMU_VERSION_MINOR << 16) |
>                      (QEMU_VERSION_MICRO << 8)));
> -        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_PIC_BASE,
> +        BOOTINFO2(param_ptr, BI_VIRT_GF_PIC_BASE,
>                     VIRT_GF_PIC_MMIO_BASE, VIRT_GF_PIC_IRQ_BASE);
> -        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_RTC_BASE,
> +        BOOTINFO2(param_ptr, BI_VIRT_GF_RTC_BASE,
>                     VIRT_GF_RTC_MMIO_BASE, VIRT_GF_RTC_IRQ_BASE);
> -        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_TTY_BASE,
> +        BOOTINFO2(param_ptr, BI_VIRT_GF_TTY_BASE,
>                     VIRT_GF_TTY_MMIO_BASE, VIRT_GF_TTY_IRQ_BASE);
> -        BOOTINFO2(cs->as, parameters_base, BI_VIRT_CTRL_BASE,
> +        BOOTINFO2(param_ptr, BI_VIRT_CTRL_BASE,
>                     VIRT_CTRL_MMIO_BASE, VIRT_CTRL_IRQ_BASE);
> -        BOOTINFO2(cs->as, parameters_base, BI_VIRT_VIRTIO_BASE,
> +        BOOTINFO2(param_ptr, BI_VIRT_VIRTIO_BASE,
>                     VIRT_VIRTIO_MMIO_BASE, VIRT_VIRTIO_IRQ_BASE);
>   
>           if (kernel_cmdline) {
> -            BOOTINFOSTR(cs->as, parameters_base, BI_COMMAND_LINE,
> +            BOOTINFOSTR(param_ptr, BI_COMMAND_LINE,
>                           kernel_cmdline);
>           }
>   
>           /* Pass seed to RNG. */
> +        param_rng_seed = param_ptr;
>           qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
> -        BOOTINFODATA(cs->as, parameters_base, BI_RNG_SEED,
> +        BOOTINFODATA(param_ptr, BI_RNG_SEED,
>                        rng_seed, sizeof(rng_seed));
>   
>           /* load initrd */
> @@ -265,13 +280,19 @@ static void virt_init(MachineState *machine)
>               initrd_base = (ram_size - initrd_size) & TARGET_PAGE_MASK;
>               load_image_targphys(initrd_filename, initrd_base,
>                                   ram_size - initrd_base);
> -            BOOTINFO2(cs->as, parameters_base, BI_RAMDISK, initrd_base,
> +            BOOTINFO2(param_ptr, BI_RAMDISK, initrd_base,
>                         initrd_size);
>           } else {
>               initrd_base = 0;
>               initrd_size = 0;
>           }
> -        BOOTINFO0(cs->as, parameters_base, BI_LAST);
> +        BOOTINFO0(param_ptr, BI_LAST);
> +        rom_add_blob_fixed_as("bootinfo", param_blob, param_ptr - param_blob,
> +                              parameters_base, cs->as);
> +        reset_info->rng_seed = rom_ptr_for_as(cs->as, parameters_base,
> +                                              param_ptr - param_blob) +
> +                               (param_rng_seed - param_blob);
> +        g_free(param_blob);
>       }
>   }
>
Richard Henderson Oct. 22, 2022, 6:41 a.m. UTC | #2
On Sat, 22 Oct 2022, 08:33 Laurent Vivier, <laurent@vivier.eu> wrote:

> Le 17/10/2022 à 22:29, Jason A. Donenfeld a écrit :
>
>
> Notes:
> - don't send your patch as a reply to a previous version
> - add an history:
>
> v4: replace  (void *)(((unsigned long)base + 3) & ~3) by
>               (void *)(((uintptr_t)base + 3) & ~3);
>


QEMU_ALIGN_PTR_UP.


r~
Jason A. Donenfeld Oct. 23, 2022, 7:09 p.m. UTC | #3
On Sat, Oct 22, 2022 at 8:41 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On Sat, 22 Oct 2022, 08:33 Laurent Vivier, <laurent@vivier.eu> wrote:
>>
>> Le 17/10/2022 à 22:29, Jason A. Donenfeld a écrit :
>>
>>
>> Notes:
>> - don't send your patch as a reply to a previous version
>> - add an history:
>>
>> v4: replace  (void *)(((unsigned long)base + 3) & ~3) by
>>               (void *)(((uintptr_t)base + 3) & ~3);
>
>
>
> QEMU_ALIGN_PTR_UP.

Will do. v5 on its way.
diff mbox series

Patch

diff --git a/hw/m68k/bootinfo.h b/hw/m68k/bootinfo.h
index 897162b818..67e6b66b7d 100644
--- a/hw/m68k/bootinfo.h
+++ b/hw/m68k/bootinfo.h
@@ -12,66 +12,66 @@ 
 #ifndef HW_M68K_BOOTINFO_H
 #define HW_M68K_BOOTINFO_H
 
-#define BOOTINFO0(as, base, id) \
+#define BOOTINFO0(base, id) \
     do { \
-        stw_phys(as, base, id); \
+        stw_p(base, id); \
         base += 2; \
-        stw_phys(as, base, sizeof(struct bi_record)); \
+        stw_p(base, sizeof(struct bi_record)); \
         base += 2; \
     } while (0)
 
-#define BOOTINFO1(as, base, id, value) \
+#define BOOTINFO1(base, id, value) \
     do { \
-        stw_phys(as, base, id); \
+        stw_p(base, id); \
         base += 2; \
-        stw_phys(as, base, sizeof(struct bi_record) + 4); \
+        stw_p(base, sizeof(struct bi_record) + 4); \
         base += 2; \
-        stl_phys(as, base, value); \
+        stl_p(base, value); \
         base += 4; \
     } while (0)
 
-#define BOOTINFO2(as, base, id, value1, value2) \
+#define BOOTINFO2(base, id, value1, value2) \
     do { \
-        stw_phys(as, base, id); \
+        stw_p(base, id); \
         base += 2; \
-        stw_phys(as, base, sizeof(struct bi_record) + 8); \
+        stw_p(base, sizeof(struct bi_record) + 8); \
         base += 2; \
-        stl_phys(as, base, value1); \
+        stl_p(base, value1); \
         base += 4; \
-        stl_phys(as, base, value2); \
+        stl_p(base, value2); \
         base += 4; \
     } while (0)
 
-#define BOOTINFOSTR(as, base, id, string) \
+#define BOOTINFOSTR(base, id, string) \
     do { \
         int i; \
-        stw_phys(as, base, id); \
+        stw_p(base, id); \
         base += 2; \
-        stw_phys(as, base, \
+        stw_p(base, \
                  (sizeof(struct bi_record) + strlen(string) + \
                   1 /* null termination */ + 3 /* padding */) & ~3); \
         base += 2; \
         for (i = 0; string[i]; i++) { \
-            stb_phys(as, base++, string[i]); \
+            stb_p(base++, string[i]); \
         } \
-        stb_phys(as, base++, 0); \
-        base = (base + 3) & ~3; \
+        stb_p(base++, 0); \
+        base = (void *)(((uintptr_t)base + 3) & ~3); \
     } while (0)
 
-#define BOOTINFODATA(as, base, id, data, len) \
+#define BOOTINFODATA(base, id, data, len) \
     do { \
         int i; \
-        stw_phys(as, base, id); \
+        stw_p(base, id); \
         base += 2; \
-        stw_phys(as, base, \
+        stw_p(base, \
                  (sizeof(struct bi_record) + len + \
                   2 /* length field */ + 3 /* padding */) & ~3); \
         base += 2; \
-        stw_phys(as, base, len); \
+        stw_p(base, len); \
         base += 2; \
         for (i = 0; i < len; ++i) { \
-            stb_phys(as, base++, data[i]); \
+            stb_p(base++, data[i]); \
         } \
-        base = (base + 3) & ~3; \
+        base = (void *)(((uintptr_t)base + 3) & ~3); \
     } while (0)
 #endif
diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
index a4590c2cb0..e09e244ddc 100644
--- a/hw/m68k/q800.c
+++ b/hw/m68k/q800.c
@@ -321,11 +321,22 @@  static const TypeInfo glue_info = {
     },
 };
 
+typedef struct {
+    M68kCPU *cpu;
+    struct bi_record *rng_seed;
+} ResetInfo;
+
 static void main_cpu_reset(void *opaque)
 {
-    M68kCPU *cpu = opaque;
+    ResetInfo *reset_info = opaque;
+    M68kCPU *cpu = reset_info->cpu;
     CPUState *cs = CPU(cpu);
 
+    if (reset_info->rng_seed) {
+        qemu_guest_getrandom_nofail((void *)reset_info->rng_seed->data + 2,
+            be16_to_cpu(*(uint16_t *)reset_info->rng_seed->data));
+    }
+
     cpu_reset(cs);
     cpu->env.aregs[7] = ldl_phys(cs->as, 0);
     cpu->env.pc = ldl_phys(cs->as, 4);
@@ -386,6 +397,7 @@  static void q800_init(MachineState *machine)
     NubusBus *nubus;
     DeviceState *glue;
     DriveInfo *dinfo;
+    ResetInfo *reset_info;
     uint8_t rng_seed[32];
 
     linux_boot = (kernel_filename != NULL);
@@ -396,9 +408,12 @@  static void q800_init(MachineState *machine)
         exit(1);
     }
 
+    reset_info = g_new0(ResetInfo, 1);
+
     /* init CPUs */
     cpu = M68K_CPU(cpu_create(machine->cpu_type));
-    qemu_register_reset(main_cpu_reset, cpu);
+    reset_info->cpu = cpu;
+    qemu_register_reset(main_cpu_reset, reset_info);
 
     /* RAM */
     memory_region_add_subregion(get_system_memory(), 0, machine->ram);
@@ -598,6 +613,14 @@  static void q800_init(MachineState *machine)
     cs = CPU(cpu);
     if (linux_boot) {
         uint64_t high;
+        void *param_blob, *param_ptr, *param_rng_seed;
+
+        if (kernel_cmdline) {
+            param_blob = g_malloc(strlen(kernel_cmdline) + 1024);
+        } else {
+            param_blob = g_malloc(1024);
+        }
+
         kernel_size = load_elf(kernel_filename, NULL, NULL, NULL,
                                &elf_entry, NULL, &high, NULL, 1,
                                EM_68K, 0, 0);
@@ -607,23 +630,24 @@  static void q800_init(MachineState *machine)
         }
         stl_phys(cs->as, 4, elf_entry); /* reset initial PC */
         parameters_base = (high + 1) & ~1;
-
-        BOOTINFO1(cs->as, parameters_base, BI_MACHTYPE, MACH_MAC);
-        BOOTINFO1(cs->as, parameters_base, BI_FPUTYPE, FPU_68040);
-        BOOTINFO1(cs->as, parameters_base, BI_MMUTYPE, MMU_68040);
-        BOOTINFO1(cs->as, parameters_base, BI_CPUTYPE, CPU_68040);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_CPUID, CPUB_68040);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_MODEL, MAC_MODEL_Q800);
-        BOOTINFO1(cs->as, parameters_base,
+        param_ptr = param_blob;
+
+        BOOTINFO1(param_ptr, BI_MACHTYPE, MACH_MAC);
+        BOOTINFO1(param_ptr, BI_FPUTYPE, FPU_68040);
+        BOOTINFO1(param_ptr, BI_MMUTYPE, MMU_68040);
+        BOOTINFO1(param_ptr, BI_CPUTYPE, CPU_68040);
+        BOOTINFO1(param_ptr, BI_MAC_CPUID, CPUB_68040);
+        BOOTINFO1(param_ptr, BI_MAC_MODEL, MAC_MODEL_Q800);
+        BOOTINFO1(param_ptr,
                   BI_MAC_MEMSIZE, ram_size >> 20); /* in MB */
-        BOOTINFO2(cs->as, parameters_base, BI_MEMCHUNK, 0, ram_size);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_VADDR,
+        BOOTINFO2(param_ptr, BI_MEMCHUNK, 0, ram_size);
+        BOOTINFO1(param_ptr, BI_MAC_VADDR,
                   VIDEO_BASE + macfb_mode->offset);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_VDEPTH, graphic_depth);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_VDIM,
+        BOOTINFO1(param_ptr, BI_MAC_VDEPTH, graphic_depth);
+        BOOTINFO1(param_ptr, BI_MAC_VDIM,
                   (graphic_height << 16) | graphic_width);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_VROW, macfb_mode->stride);
-        BOOTINFO1(cs->as, parameters_base, BI_MAC_SCCBASE, SCC_BASE);
+        BOOTINFO1(param_ptr, BI_MAC_VROW, macfb_mode->stride);
+        BOOTINFO1(param_ptr, BI_MAC_SCCBASE, SCC_BASE);
 
         rom = g_malloc(sizeof(*rom));
         memory_region_init_ram_ptr(rom, NULL, "m68k_fake_mac.rom",
@@ -632,13 +656,14 @@  static void q800_init(MachineState *machine)
         memory_region_add_subregion(get_system_memory(), MACROM_ADDR, rom);
 
         if (kernel_cmdline) {
-            BOOTINFOSTR(cs->as, parameters_base, BI_COMMAND_LINE,
+            BOOTINFOSTR(param_ptr, BI_COMMAND_LINE,
                         kernel_cmdline);
         }
 
         /* Pass seed to RNG. */
+        param_rng_seed = param_ptr;
         qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
-        BOOTINFODATA(cs->as, parameters_base, BI_RNG_SEED,
+        BOOTINFODATA(param_ptr, BI_RNG_SEED,
                      rng_seed, sizeof(rng_seed));
 
         /* load initrd */
@@ -653,13 +678,19 @@  static void q800_init(MachineState *machine)
             initrd_base = (ram_size - initrd_size) & TARGET_PAGE_MASK;
             load_image_targphys(initrd_filename, initrd_base,
                                 ram_size - initrd_base);
-            BOOTINFO2(cs->as, parameters_base, BI_RAMDISK, initrd_base,
+            BOOTINFO2(param_ptr, BI_RAMDISK, initrd_base,
                       initrd_size);
         } else {
             initrd_base = 0;
             initrd_size = 0;
         }
-        BOOTINFO0(cs->as, parameters_base, BI_LAST);
+        BOOTINFO0(param_ptr, BI_LAST);
+        rom_add_blob_fixed_as("bootinfo", param_blob, param_ptr - param_blob,
+                              parameters_base, cs->as);
+        reset_info->rng_seed = rom_ptr_for_as(cs->as, parameters_base,
+                                              param_ptr - param_blob) +
+                               (param_rng_seed - param_blob);
+        g_free(param_blob);
     } else {
         uint8_t *ptr;
         /* allocate and load BIOS */
diff --git a/hw/m68k/virt.c b/hw/m68k/virt.c
index f7b903ea1b..89c4108eb5 100644
--- a/hw/m68k/virt.c
+++ b/hw/m68k/virt.c
@@ -89,6 +89,7 @@  typedef struct {
     M68kCPU *cpu;
     hwaddr initial_pc;
     hwaddr initial_stack;
+    struct bi_record *rng_seed;
 } ResetInfo;
 
 static void main_cpu_reset(void *opaque)
@@ -97,6 +98,11 @@  static void main_cpu_reset(void *opaque)
     M68kCPU *cpu = reset_info->cpu;
     CPUState *cs = CPU(cpu);
 
+    if (reset_info->rng_seed) {
+        qemu_guest_getrandom_nofail((void *)reset_info->rng_seed->data + 2,
+            be16_to_cpu(*(uint16_t *)reset_info->rng_seed->data));
+    }
+
     cpu_reset(cs);
     cpu->env.aregs[7] = reset_info->initial_stack;
     cpu->env.pc = reset_info->initial_pc;
@@ -212,6 +218,13 @@  static void virt_init(MachineState *machine)
     if (kernel_filename) {
         CPUState *cs = CPU(cpu);
         uint64_t high;
+        void *param_blob, *param_ptr, *param_rng_seed;
+
+        if (kernel_cmdline) {
+            param_blob = g_malloc(strlen(kernel_cmdline) + 1024);
+        } else {
+            param_blob = g_malloc(1024);
+        }
 
         kernel_size = load_elf(kernel_filename, NULL, NULL, NULL,
                                &elf_entry, NULL, &high, NULL, 1,
@@ -222,35 +235,37 @@  static void virt_init(MachineState *machine)
         }
         reset_info->initial_pc = elf_entry;
         parameters_base = (high + 1) & ~1;
+        param_ptr = param_blob;
 
-        BOOTINFO1(cs->as, parameters_base, BI_MACHTYPE, MACH_VIRT);
-        BOOTINFO1(cs->as, parameters_base, BI_FPUTYPE, FPU_68040);
-        BOOTINFO1(cs->as, parameters_base, BI_MMUTYPE, MMU_68040);
-        BOOTINFO1(cs->as, parameters_base, BI_CPUTYPE, CPU_68040);
-        BOOTINFO2(cs->as, parameters_base, BI_MEMCHUNK, 0, ram_size);
+        BOOTINFO1(param_ptr, BI_MACHTYPE, MACH_VIRT);
+        BOOTINFO1(param_ptr, BI_FPUTYPE, FPU_68040);
+        BOOTINFO1(param_ptr, BI_MMUTYPE, MMU_68040);
+        BOOTINFO1(param_ptr, BI_CPUTYPE, CPU_68040);
+        BOOTINFO2(param_ptr, BI_MEMCHUNK, 0, ram_size);
 
-        BOOTINFO1(cs->as, parameters_base, BI_VIRT_QEMU_VERSION,
+        BOOTINFO1(param_ptr, BI_VIRT_QEMU_VERSION,
                   ((QEMU_VERSION_MAJOR << 24) | (QEMU_VERSION_MINOR << 16) |
                    (QEMU_VERSION_MICRO << 8)));
-        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_PIC_BASE,
+        BOOTINFO2(param_ptr, BI_VIRT_GF_PIC_BASE,
                   VIRT_GF_PIC_MMIO_BASE, VIRT_GF_PIC_IRQ_BASE);
-        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_RTC_BASE,
+        BOOTINFO2(param_ptr, BI_VIRT_GF_RTC_BASE,
                   VIRT_GF_RTC_MMIO_BASE, VIRT_GF_RTC_IRQ_BASE);
-        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_TTY_BASE,
+        BOOTINFO2(param_ptr, BI_VIRT_GF_TTY_BASE,
                   VIRT_GF_TTY_MMIO_BASE, VIRT_GF_TTY_IRQ_BASE);
-        BOOTINFO2(cs->as, parameters_base, BI_VIRT_CTRL_BASE,
+        BOOTINFO2(param_ptr, BI_VIRT_CTRL_BASE,
                   VIRT_CTRL_MMIO_BASE, VIRT_CTRL_IRQ_BASE);
-        BOOTINFO2(cs->as, parameters_base, BI_VIRT_VIRTIO_BASE,
+        BOOTINFO2(param_ptr, BI_VIRT_VIRTIO_BASE,
                   VIRT_VIRTIO_MMIO_BASE, VIRT_VIRTIO_IRQ_BASE);
 
         if (kernel_cmdline) {
-            BOOTINFOSTR(cs->as, parameters_base, BI_COMMAND_LINE,
+            BOOTINFOSTR(param_ptr, BI_COMMAND_LINE,
                         kernel_cmdline);
         }
 
         /* Pass seed to RNG. */
+        param_rng_seed = param_ptr;
         qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
-        BOOTINFODATA(cs->as, parameters_base, BI_RNG_SEED,
+        BOOTINFODATA(param_ptr, BI_RNG_SEED,
                      rng_seed, sizeof(rng_seed));
 
         /* load initrd */
@@ -265,13 +280,19 @@  static void virt_init(MachineState *machine)
             initrd_base = (ram_size - initrd_size) & TARGET_PAGE_MASK;
             load_image_targphys(initrd_filename, initrd_base,
                                 ram_size - initrd_base);
-            BOOTINFO2(cs->as, parameters_base, BI_RAMDISK, initrd_base,
+            BOOTINFO2(param_ptr, BI_RAMDISK, initrd_base,
                       initrd_size);
         } else {
             initrd_base = 0;
             initrd_size = 0;
         }
-        BOOTINFO0(cs->as, parameters_base, BI_LAST);
+        BOOTINFO0(param_ptr, BI_LAST);
+        rom_add_blob_fixed_as("bootinfo", param_blob, param_ptr - param_blob,
+                              parameters_base, cs->as);
+        reset_info->rng_seed = rom_ptr_for_as(cs->as, parameters_base,
+                                              param_ptr - param_blob) +
+                               (param_rng_seed - param_blob);
+        g_free(param_blob);
     }
 }