m68k: rework BI_VIRT_RNG_SEED as BI_RNG_SEED
Following a change on the kernel side (see link), pass BI_RNG_SEED
instead of BI_VIRT_RNG_SEED. This should have no impact on
compatibility, as there will simply be no effect if it's an old kernel,
which is how things have always been. We then use this as an opportunity
to add this to q800, since now we can, which is a nice improvement.
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Laurent Vivier <laurent@vivier.eu>
Link: https://lore.kernel.org/lkml/20220923170340.4099226-3-Jason@zx2c4.com/
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220926113900.1256630-1-Jason@zx2c4.com>
[lv: s/^I/ /g]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
index 101ab0f..a4590c2 100644
--- a/hw/m68k/q800.c
+++ b/hw/m68k/q800.c
@@ -23,6 +23,7 @@
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "qemu/datadir.h"
+#include "qemu/guest-random.h"
#include "sysemu/sysemu.h"
#include "cpu.h"
#include "hw/boards.h"
@@ -385,6 +386,7 @@
NubusBus *nubus;
DeviceState *glue;
DriveInfo *dinfo;
+ uint8_t rng_seed[32];
linux_boot = (kernel_filename != NULL);
@@ -634,6 +636,11 @@
kernel_cmdline);
}
+ /* Pass seed to RNG. */
+ qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
+ BOOTINFODATA(cs->as, parameters_base, BI_RNG_SEED,
+ rng_seed, sizeof(rng_seed));
+
/* load initrd */
if (initrd_filename) {
initrd_size = get_image_size(initrd_filename);
diff --git a/hw/m68k/virt.c b/hw/m68k/virt.c
index 2f3ffc0..f7b903e 100644
--- a/hw/m68k/virt.c
+++ b/hw/m68k/virt.c
@@ -248,10 +248,10 @@
kernel_cmdline);
}
- /* Pass seed to RNG. */
- qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
- BOOTINFODATA(cs->as, parameters_base, BI_VIRT_RNG_SEED,
- rng_seed, sizeof(rng_seed));
+ /* Pass seed to RNG. */
+ qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
+ BOOTINFODATA(cs->as, parameters_base, BI_RNG_SEED,
+ rng_seed, sizeof(rng_seed));
/* load initrd */
if (initrd_filename) {
diff --git a/include/standard-headers/asm-m68k/bootinfo-virt.h b/include/standard-headers/asm-m68k/bootinfo-virt.h
index 1b1ffd4..75ac6bb 100644
--- a/include/standard-headers/asm-m68k/bootinfo-virt.h
+++ b/include/standard-headers/asm-m68k/bootinfo-virt.h
@@ -12,7 +12,9 @@
#define BI_VIRT_GF_TTY_BASE 0x8003
#define BI_VIRT_VIRTIO_BASE 0x8004
#define BI_VIRT_CTRL_BASE 0x8005
-#define BI_VIRT_RNG_SEED 0x8006
+
+/* No longer used -- replaced with BI_RNG_SEED -- but don't reuse this index:
+ * #define BI_VIRT_RNG_SEED 0x8006 */
#define VIRT_BOOTI_VERSION MK_BI_VERSION(2, 0)
diff --git a/include/standard-headers/asm-m68k/bootinfo.h b/include/standard-headers/asm-m68k/bootinfo.h
index 7b790e8..b7a8dd2 100644
--- a/include/standard-headers/asm-m68k/bootinfo.h
+++ b/include/standard-headers/asm-m68k/bootinfo.h
@@ -57,7 +57,13 @@
/* (struct mem_info) */
#define BI_COMMAND_LINE 0x0007 /* kernel command line parameters */
/* (string) */
-
+/*
+ * A random seed used to initialize the RNG. Record format:
+ *
+ * - length [ 2 bytes, 16-bit big endian ]
+ * - seed data [ `length` bytes, padded to preserve 4-byte struct alignment ]
+ */
+#define BI_RNG_SEED 0x0008
/*
* Linux/m68k Architectures (BI_MACHTYPE)
