Re: [Qemu-devel] [PATCH] hw/vexpress.c: Add NOR flash model

[Peter Maydell]

On 20 March 2012 16:00, walimis <address@hidden> wrote:
> On Tue, Mar 20, 2012 at 03:13:33PM +0000, Peter Maydell wrote:
>>On 20 March 2012 14:57, Liming Wang <address@hidden> wrote:
>>> Vexpress motherboard has two 2x16 NOR flash, but pflash_cfi01
>>> doesn't support interleaving, so here only models two 1x32 flash.
>>> Although it's not exactly modeled, it works fine for running linux.
>>>
>>> Signed-off-by: Liming Wang <address@hidden>
>>> ---
>>>  hw/vexpress.c |   19 +++++++++++++++++--
>>>  1 files changed, 17 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/hw/vexpress.c b/hw/vexpress.c
>>> index b9aafec..921b01b 100644
>>> --- a/hw/vexpress.c
>>> +++ b/hw/vexpress.c
>>> @@ -29,9 +29,13 @@
>>>  #include "sysemu.h"
>>>  #include "boards.h"
>>>  #include "exec-memory.h"
>>> +#include "flash.h"
>>> +#include "blockdev.h"
>>>
>>>  #define VEXPRESS_BOARD_ID 0x8e0
>>>
>>> +#define VEXPRESS_FLASH_SIZE 0x04000000
>>> +
>>>  static struct arm_boot_info vexpress_binfo;
>>>
>>>  /* Address maps for peripherals:
>>> @@ -355,6 +359,9 @@ static void vexpress_common_init(const VEDBoardInfo 
>>> *daughterboard,
>>>     MemoryRegion *vram = g_new(MemoryRegion, 1);
>>>     MemoryRegion *sram = g_new(MemoryRegion, 1);
>>>     const target_phys_addr_t *map = daughterboard->motherboard_map;
>>> +    DriveInfo *dinfo = NULL;
>>> +    uint32_t sector_len = 256 * 1024;
>>> +    int i = 0;
>>>
>>>     daughterboard->init(daughterboard, ram_size, cpu_model, pic, &proc_id);
>>>
>>> @@ -405,9 +412,17 @@ static void vexpress_common_init(const VEDBoardInfo 
>>> *daughterboard,
>>>
>>>     sysbus_create_simple("pl111", map[VE_CLCD], pic[14]);
>>>
>>> -    /* VE_NORFLASH0: not modelled */
>>> +    for(i = 0; i < 2; i++) {
>>> +       dinfo = drive_get(IF_PFLASH, 0, i);
>>> +        if (dinfo) {
>>> +           pflash_cfi01_register(((i == 0) ? map[VE_NORFLASH0] : 
>>> map[VE_NORFLASH1]), NULL,
>>> +                           ((i == 0) ? "vexpress.flash0" : 
>>> "vexpress:flash1"),
>>> +                           VEXPRESS_FLASH_SIZE, dinfo->bdrv, sector_len,
>>> +                           VEXPRESS_FLASH_SIZE / sector_len, 4,
>>> +                           0, 0x89, 0x89, 0x19, 0);
>>> +       }
>>> +    }
>>
>>As it stands this will stick flash0 over the top of RAM at address
>>zero on the vexpress-a15, since there VE_NORFLASH0 is 0. I think
>>that was a mistake, and we should have it in line with the legacy
> Sorry, I don't notice the situation for vexpress-a15. It seems to be
> fixed to fit both vexpress-a9 and vexpress-a15. Unfortunately, I have
> no infomation about memory map for vexpress-a15.

The docs are publicly available:
http://infocenter.arm.com/help/topic/com.arm.doc.dui0604a/ch03s02s01.html

As I say basically you just want to change the a15's value of
NORFLASH0 to 0x0800000 and delete all references to NORFLASH0ALIAS.

>>memory map, ie NORFLASH0 at 0x0800000 (and drop NORFLASH0ALIAS).
>>
>>What's your use case for this? Do we need to/want to implement
>>the memory remapping so you can have flash at address 0 and
>>boot out of it?
> I don't want to boot from flash, but only to model flash to erase/mount
> on linux guest os. We know that on vexpress-a9 board, u-boot is loaded
> by the board's monitor, not by itself.

Mmm, you'd need a boot monitor in the flash too. I have vague
plans to have a go at trying the UEFI for vexpress-a9 here...

-- PMM