Re: [Qemu-devel] [Patch v2 4/8] target_arm: Remove memory region init from armv7m_init

[Peter Crosthwaite]

On Fri, Sep 19, 2014 at 2:54 PM, Alistair Francis <address@hidden> wrote:
> This patch moves the memory region init code from the
> armv7m_init function to the stellaris_init function
>
> Signed-off-by: Alistair Francis <address@hidden>
> ---
> V2:
>  - Change the memory region names to match the machine
>
>  hw/arm/armv7m.c    | 15 +--------------
>  hw/arm/stellaris.c | 23 +++++++++++++++++++----
>  2 files changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c
> index aedef13..5c1f7b3 100644
> --- a/hw/arm/armv7m.c
> +++ b/hw/arm/armv7m.c
> @@ -163,7 +163,7 @@ static void armv7m_reset(void *opaque)
>  }
>
>  /* Init CPU and memory for a v7-M based board.
> -   flash_size and sram_size are in kb.
> +   flash_size and sram_size are in bytes.
>     Returns the NVIC array.  */
>
>  qemu_irq *armv7m_init(MemoryRegion *system_memory,
> @@ -180,13 +180,8 @@ qemu_irq *armv7m_init(MemoryRegion *system_memory,
>      uint64_t lowaddr;
>      int i;
>      int big_endian;
> -    MemoryRegion *sram = g_new(MemoryRegion, 1);
> -    MemoryRegion *flash = g_new(MemoryRegion, 1);
>      MemoryRegion *hack = g_new(MemoryRegion, 1);
>
> -    flash_size *= 1024;
> -    sram_size *= 1024;
> -
>      if (cpu_model == NULL) {
>         cpu_model = "cortex-m3";
>      }
> @@ -209,14 +204,6 @@ qemu_irq *armv7m_init(MemoryRegion *system_memory,
>      code_size = ram_size - sram_size;
>  #endif
>
> -    /* Flash programming is done via the SCU, so pretend it is ROM.  */
> -    memory_region_init_ram(flash, NULL, "armv7m.flash", flash_size);
> -    vmstate_register_ram_global(flash);
> -    memory_region_set_readonly(flash, true);
> -    memory_region_add_subregion(system_memory, 0, flash);
> -    memory_region_init_ram(sram, NULL, "armv7m.sram", sram_size);
> -    vmstate_register_ram_global(sram);
> -    memory_region_add_subregion(system_memory, 0x20000000, sram);
>      armv7m_bitband_init();
>
>      nvic = qdev_create(NULL, "armv7m_nvic");
> diff --git a/hw/arm/stellaris.c b/hw/arm/stellaris.c
> index 64bd4b4..9738722 100644
> --- a/hw/arm/stellaris.c
> +++ b/hw/arm/stellaris.c
> @@ -1220,10 +1220,25 @@ static void stellaris_init(const char 
> *kernel_filename, const char *cpu_model,
>      int i;
>      int j;
>
> -    flash_size = ((board->dc0 & 0xffff) + 1) << 1;
> -    sram_size = (board->dc0 >> 18) + 1;
> -    pic = armv7m_init(get_system_memory(),
> -                      flash_size, sram_size, kernel_filename, cpu_model);
> +    MemoryRegion *sram = g_new(MemoryRegion, 1);
> +    MemoryRegion *flash = g_new(MemoryRegion, 1);
> +    MemoryRegion *system_memory = get_system_memory();
> +
> +    flash_size = (((board->dc0 & 0xffff) + 1) << 1) * 1024;
> +    sram_size = ((board->dc0 >> 18) + 1) * 1024;
> +
> +    /* Flash programming is done via the SCU, so pretend it is ROM.  */
> +    memory_region_init_ram(flash, NULL, "stellaris.flash", flash_size);
> +    vmstate_register_ram_global(flash);
> +    memory_region_set_readonly(flash, true);
> +    memory_region_add_subregion(system_memory, 0, flash);
> +
> +    memory_region_init_ram(sram, NULL, "stellaris.sram", sram_size);
> +    vmstate_register_ram_global(sram);
> +    memory_region_add_subregion(system_memory, 0x20000000, sram);
> +
> +    pic = armv7m_init(system_memory, flash_size, sram_size,
> +                      kernel_filename, cpu_model);

So I can see why flash_size is needed by armv7m_init for the sake of
capping the loaded image size. While touching the code you could
change this to a better name "mem_size" or something to indicate that
the arg is now the size of an implementation independent memory region
at 0.

sram_size should be unneeded. There some ancient (pre 2007) #if 0 code
that refs it aside from the stuff you delete but I think we can safely
ignore that (or patch to delete it).

Regards,
Peter

>
>      if (board->dc1 & (1 << 16)) {
>          dev = sysbus_create_varargs(TYPE_STELLARIS_ADC, 0x40038000,
> --
> 1.9.1
>
>