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[v4,6/6] hw/ppc/epapr: Do not swap ePAPR magic value

Message ID 20241220213103.6314-7-philmd@linaro.org
State New
Headers show
Series hw/ppc: Remove tswap() calls | expand

Commit Message

Philippe Mathieu-Daudé Dec. 20, 2024, 9:31 p.m. UTC 
The ePAPR magic value in $r6 doesn't need to be byte swapped.

See ePAPR-v1.1.pdf chapter 5.4.1 "Boot CPU Initial Register State"
and the following mailing-list threads:
https://lore.kernel.org/qemu-devel/CAFEAcA_NR4XW5DNL4nq7vnH4XRH5UWbhQCxuLyKqYk6_FCBrAA@mail.gmail.com/
https://lore.kernel.org/qemu-devel/D6F93NM6OW2L.2FDO88L38PABR@gmail.com/

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 hw/ppc/sam460ex.c     | 2 +-
 hw/ppc/virtex_ml507.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Comments

BALATON Zoltan Dec. 22, 2024, 7:08 p.m. UTC | #1 
On Fri, 20 Dec 2024, Philippe Mathieu-Daudé wrote:
> The ePAPR magic value in $r6 doesn't need to be byte swapped.
>
> See ePAPR-v1.1.pdf chapter 5.4.1 "Boot CPU Initial Register State"
> and the following mailing-list threads:
> https://lore.kernel.org/qemu-devel/CAFEAcA_NR4XW5DNL4nq7vnH4XRH5UWbhQCxuLyKqYk6_FCBrAA@mail.gmail.com/
> https://lore.kernel.org/qemu-devel/D6F93NM6OW2L.2FDO88L38PABR@gmail.com/
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

The Linux image I have still seems to boot on sam460ex so

Tested-by: BALATON Zoltan <balaton@eik.bme.hu>

> ---
> hw/ppc/sam460ex.c     | 2 +-
> hw/ppc/virtex_ml507.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/ppc/sam460ex.c b/hw/ppc/sam460ex.c
> index 78e2a46e753..db9c8f3fa6e 100644
> --- a/hw/ppc/sam460ex.c
> +++ b/hw/ppc/sam460ex.c
> @@ -234,7 +234,7 @@ static void main_cpu_reset(void *opaque)
>
>         /* Create a mapping for the kernel.  */
>         booke_set_tlb(&env->tlb.tlbe[0], 0, 0, 1 << 31);
> -        env->gpr[6] = tswap32(EPAPR_MAGIC);
> +        env->gpr[6] = EPAPR_MAGIC;
>         env->gpr[7] = (16 * MiB) - 8; /* bi->ima_size; */
>
>     } else {
> diff --git a/hw/ppc/virtex_ml507.c b/hw/ppc/virtex_ml507.c
> index f378e5c4a90..6197d31d88f 100644
> --- a/hw/ppc/virtex_ml507.c
> +++ b/hw/ppc/virtex_ml507.c
> @@ -119,7 +119,7 @@ static void main_cpu_reset(void *opaque)
>     /* Create a mapping spanning the 32bit addr space. */
>     booke_set_tlb(&env->tlb.tlbe[0], 0, 0, 1U << 31);
>     booke_set_tlb(&env->tlb.tlbe[1], 0x80000000, 0x80000000, 1U << 31);
> -    env->gpr[6] = tswap32(EPAPR_MAGIC);
> +    env->gpr[6] = EPAPR_MAGIC;
>     env->gpr[7] = bi->ima_size;
> }
>
>
diff mbox series

Patch

diff --git a/hw/ppc/sam460ex.c b/hw/ppc/sam460ex.c
index 78e2a46e753..db9c8f3fa6e 100644
--- a/hw/ppc/sam460ex.c
+++ b/hw/ppc/sam460ex.c
@@ -234,7 +234,7 @@  static void main_cpu_reset(void *opaque)
 
         /* Create a mapping for the kernel.  */
         booke_set_tlb(&env->tlb.tlbe[0], 0, 0, 1 << 31);
-        env->gpr[6] = tswap32(EPAPR_MAGIC);
+        env->gpr[6] = EPAPR_MAGIC;
         env->gpr[7] = (16 * MiB) - 8; /* bi->ima_size; */
 
     } else {
diff --git a/hw/ppc/virtex_ml507.c b/hw/ppc/virtex_ml507.c
index f378e5c4a90..6197d31d88f 100644
--- a/hw/ppc/virtex_ml507.c
+++ b/hw/ppc/virtex_ml507.c
@@ -119,7 +119,7 @@  static void main_cpu_reset(void *opaque)
     /* Create a mapping spanning the 32bit addr space. */
     booke_set_tlb(&env->tlb.tlbe[0], 0, 0, 1U << 31);
     booke_set_tlb(&env->tlb.tlbe[1], 0x80000000, 0x80000000, 1U << 31);
-    env->gpr[6] = tswap32(EPAPR_MAGIC);
+    env->gpr[6] = EPAPR_MAGIC;
     env->gpr[7] = bi->ima_size;
 }