Re: [Qemu-devel] [PATCH v4] hw/pc: Support system flash memory with -pflash parameter

[Jordan Justen]

On Sat, Jul 23, 2011 at 08:51, Anthony Liguori <address@hidden> wrote:
> On 07/08/2011 02:37 PM, Jordan Justen wrote:
>>
>> If -pflash is specified and -bios is specified then pflash will
>> be mapped just below the system rom using hw/pflash_cfi01.c.
>>
>> If -pflash is specified on the command line, but -bios is
>> not specified, then 'bios.bin' will NOT be loaded, and
>> instead the -pflash flash image will be mapped just below
>> 4GB in place of the normal rom image.
>
> This is way too tied to the pc platform to be this generic.
>
> I think a better approach would be to default to having unit=0 of IF_PFLASH
> default to a read-only BDS that points to bios.bin.  -bios would just be a
> short cut to use a different file name but you should be able to override
> with -drive too.
>
> And to really simplify things, you could add a readonly flag to -bios such
> that you could do:
>
> -bios foo.img,readonly=off
>
> Which is what I think you're looking for semantically.

There seemed to be some feedback on the list interested in preserving
a read-only firmware, and just adding a flash region.

So, for example, the firmware could be read from a common system
location like is generally done with bios.bin today, and VM instance
specific flash region could still be added.

If the entire firmware is moved to a separate VM instance specific
flash, then firmware update also gets complicated.  It is no longer
just a matter of updating the qemu firmware package in your distro's
package management system.

What about taking your idea, but adding a second drive that would be
mapped just below the 1st if it is specified with -drive?

Thanks,

-Jordan

>
> Regards,
>
> Anthony Liguori
>
>>
>> Signed-off-by: Jordan Justen<address@hidden>
>> Reviewed-by: Aurelien Jarno<address@hidden>
>
>
>
>> ---
>>  default-configs/i386-softmmu.mak   |    1 +
>>  default-configs/x86_64-softmmu.mak |    1 +
>>  hw/pc.c                            |  161
>> +++++++++++++++++++++++++++---------
>>  3 files changed, 125 insertions(+), 38 deletions(-)
>>
>> diff --git a/default-configs/i386-softmmu.mak
>> b/default-configs/i386-softmmu.mak
>> index 55589fa..8697cd4 100644
>> --- a/default-configs/i386-softmmu.mak
>> +++ b/default-configs/i386-softmmu.mak
>> @@ -21,3 +21,4 @@ CONFIG_PIIX_PCI=y
>>  CONFIG_SOUND=y
>>  CONFIG_HPET=y
>>  CONFIG_APPLESMC=y
>> +CONFIG_PFLASH_CFI01=y
>> diff --git a/default-configs/x86_64-softmmu.mak
>> b/default-configs/x86_64-softmmu.mak
>> index 8895028..eca9284 100644
>> --- a/default-configs/x86_64-softmmu.mak
>> +++ b/default-configs/x86_64-softmmu.mak
>> @@ -21,3 +21,4 @@ CONFIG_PIIX_PCI=y
>>  CONFIG_SOUND=y
>>  CONFIG_HPET=y
>>  CONFIG_APPLESMC=y
>> +CONFIG_PFLASH_CFI01=y
>> diff --git a/hw/pc.c b/hw/pc.c
>> index a3e8539..e25354f 100644
>> --- a/hw/pc.c
>> +++ b/hw/pc.c
>> @@ -41,6 +41,7 @@
>>  #include "sysemu.h"
>>  #include "blockdev.h"
>>  #include "ui/qemu-spice.h"
>> +#include "flash.h"
>>
>>  /* output Bochs bios info messages */
>>  //#define DEBUG_BIOS
>> @@ -957,70 +958,154 @@ void pc_cpus_init(const char *cpu_model)
>>      }
>>  }
>>
>> -void pc_memory_init(const char *kernel_filename,
>> -                    const char *kernel_cmdline,
>> -                    const char *initrd_filename,
>> -                    ram_addr_t below_4g_mem_size,
>> -                    ram_addr_t above_4g_mem_size)
>> +static void pc_isa_bios_init(ram_addr_t ram_offset, int ram_size)
>>  {
>> -    char *filename;
>> -    int ret, linux_boot, i;
>> -    ram_addr_t ram_addr, bios_offset, option_rom_offset;
>> -    int bios_size, isa_bios_size;
>> -    void *fw_cfg;
>> -
>> -    linux_boot = (kernel_filename != NULL);
>> +    int isa_bios_size;
>>
>> -    /* allocate RAM */
>> -    ram_addr = qemu_ram_alloc(NULL, "pc.ram",
>> -                              below_4g_mem_size + above_4g_mem_size);
>> -    cpu_register_physical_memory(0, 0xa0000, ram_addr);
>> -    cpu_register_physical_memory(0x100000,
>> -                 below_4g_mem_size - 0x100000,
>> -                 ram_addr + 0x100000);
>> -    if (above_4g_mem_size>  0) {
>> -        cpu_register_physical_memory(0x100000000ULL, above_4g_mem_size,
>> -                                     ram_addr + below_4g_mem_size);
>> +    /* map the last 128KB of the BIOS in ISA space */
>> +    isa_bios_size = ram_size;
>> +    if (isa_bios_size>  (128 * 1024)) {
>> +        isa_bios_size = 128 * 1024;
>>      }
>> +    ram_offset = ram_offset + ram_size - isa_bios_size;
>> +    cpu_register_physical_memory(0x100000 - isa_bios_size,
>> +                                 isa_bios_size,
>> +                                 ram_offset | IO_MEM_ROM);
>> +}
>> +
>> +static int pc_system_rom_init(void)
>> +{
>> +    int ret;
>> +    int bios_size;
>> +    ram_addr_t bios_offset;
>> +    char *filename;
>>
>>      /* BIOS load */
>> -    if (bios_name == NULL)
>> +    if (bios_name == NULL) {
>>          bios_name = BIOS_FILENAME;
>> +    }
>>      filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
>>      if (filename) {
>>          bios_size = get_image_size(filename);
>>      } else {
>>          bios_size = -1;
>>      }
>> -    if (bios_size<= 0 ||
>> -        (bios_size % 65536) != 0) {
>> -        goto bios_error;
>> +
>> +    if (bios_size<= 0 || (bios_size % 65536) != 0) {
>> +        ret = -1;
>> +    } else {
>> +        bios_offset = qemu_ram_alloc(NULL, "pc.bios", bios_size);
>> +        ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
>>      }
>> -    bios_offset = qemu_ram_alloc(NULL, "pc.bios", bios_size);
>> -    ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
>> +
>>      if (ret != 0) {
>> -    bios_error:
>>          fprintf(stderr, "qemu: could not load PC BIOS '%s'\n",
>> bios_name);
>>          exit(1);
>>      }
>> +
>>      if (filename) {
>>          qemu_free(filename);
>>      }
>> -    /* map the last 128KB of the BIOS in ISA space */
>> -    isa_bios_size = bios_size;
>> -    if (isa_bios_size>  (128 * 1024))
>> -        isa_bios_size = 128 * 1024;
>> -    cpu_register_physical_memory(0x100000 - isa_bios_size,
>> -                                 isa_bios_size,
>> -                                 (bios_offset + bios_size -
>> isa_bios_size) | IO_MEM_ROM);
>>
>> -    option_rom_offset = qemu_ram_alloc(NULL, "pc.rom", PC_ROM_SIZE);
>> -    cpu_register_physical_memory(PC_ROM_MIN_VGA, PC_ROM_SIZE,
>> option_rom_offset);
>> +    pc_isa_bios_init(bios_offset, bios_size);
>>
>>      /* map all the bios at the top of memory */
>>      cpu_register_physical_memory((uint32_t)(-bios_size),
>>                                   bios_size, bios_offset | IO_MEM_ROM);
>>
>> +    return bios_size;
>> +}
>> +
>> +static void pc_system_flash_init(DriveInfo *pflash_drv, int rom_size)
>> +{
>> +    BlockDriverState *bdrv;
>> +    int64_t size;
>> +    target_phys_addr_t phys_addr;
>> +    ram_addr_t addr;
>> +    int sector_bits, sector_size;
>> +
>> +    bdrv = NULL;
>> +
>> +    bdrv = pflash_drv->bdrv;
>> +    size = bdrv_getlength(pflash_drv->bdrv);
>> +    sector_bits = 12;
>> +    sector_size = 1<<  sector_bits;
>> +
>> +    if ((size % sector_size) != 0) {
>> +        fprintf(stderr,
>> +                "qemu: -pflash size must be a multiple of 0x%x\n",
>> +                sector_size);
>> +        exit(1);
>> +    }
>> +
>> +    phys_addr = 0x100000000ULL - rom_size - size;
>> +    addr = qemu_ram_alloc(NULL, "system.flash", size);
>> +    DPRINTF("flash addr: 0x%lx\n", (int64_t)phys_addr);
>> +    pflash_cfi01_register(phys_addr, addr, bdrv,
>> +                          sector_size, size>>  sector_bits,
>> +                          4, 0x0000, 0x0000, 0x0000, 0x0000, 0);
>> +
>> +    if (rom_size == 0) {
>> +        pc_isa_bios_init(addr, size);
>> +    }
>> +}
>> +
>> +static void pc_system_firmware_init(void)
>> +{
>> +    int flash_present, rom_present;
>> +    int rom_size;
>> +    DriveInfo *pflash_drv;
>> +
>> +    pflash_drv = drive_get(IF_PFLASH, 0, 0);
>> +    flash_present = (pflash_drv != NULL);
>> +
>> +    /* Load rom if -bios is used or if -pflash is not used */
>> +    rom_present = ((bios_name != NULL) || !flash_present);
>> +
>> +    /* If rom is present, then it is mapped just below 4GB */
>> +    if (rom_present) {
>> +        rom_size = pc_system_rom_init();
>> +    } else {
>> +        rom_size = 0;
>> +    }
>> +
>> +    /* If flash is present, then it is mapped just below the rom, or
>> +     * just below 4GB when rom is not present. */
>> +    if (flash_present) {
>> +        pc_system_flash_init(pflash_drv, rom_size);
>> +    }
>> +}
>> +
>> +void pc_memory_init(const char *kernel_filename,
>> +                    const char *kernel_cmdline,
>> +                    const char *initrd_filename,
>> +                    ram_addr_t below_4g_mem_size,
>> +                    ram_addr_t above_4g_mem_size)
>> +{
>> +    int linux_boot, i;
>> +    ram_addr_t ram_addr, option_rom_offset;
>> +    void *fw_cfg;
>> +
>> +    linux_boot = (kernel_filename != NULL);
>> +
>> +    /* allocate RAM */
>> +    ram_addr = qemu_ram_alloc(NULL, "pc.ram",
>> +                              below_4g_mem_size + above_4g_mem_size);
>> +    cpu_register_physical_memory(0, 0xa0000, ram_addr);
>> +    cpu_register_physical_memory(0x100000,
>> +                 below_4g_mem_size - 0x100000,
>> +                 ram_addr + 0x100000);
>> +    if (above_4g_mem_size>  0) {
>> +        cpu_register_physical_memory(0x100000000ULL, above_4g_mem_size,
>> +                                     ram_addr + below_4g_mem_size);
>> +    }
>> +
>> +    /* Initialize ROM or flash ranges for PC firmware */
>> +    pc_system_firmware_init();
>> +
>> +    option_rom_offset = qemu_ram_alloc(NULL, "pc.rom", PC_ROM_SIZE);
>> +    cpu_register_physical_memory(PC_ROM_MIN_VGA, PC_ROM_SIZE,
>> option_rom_offset);
>> +
>>      fw_cfg = bochs_bios_init();
>>      rom_set_fw(fw_cfg);
>>
>
>
>