video/fb: kernel build framebuffer support

This supports running fb demo app in kernel build with new
config `rv-virt/kfb64`. The demo shows colored rectangles
in graphic window with the following console logs:

```
nsh> cat /proc/version
NuttX version 12.4.0 1ea10ddacc-dirty May  3 2024 07:03:59 rv-virt/kfb64
nsh> fb
VideoInfo:
      fmt: 13
     xres: 640
     yres: 480
  nplanes: 1
PlaneInfo (plane 0):
    fbmem: 0x80218010
    fblen: 1228800
   stride: 2560
  display: 0
      bpp: 32
Mapped FB: 0xc2000010
 0: (  0,  0) (640,480)
 1: ( 58, 43) (524,394)
 2: (116, 86) (408,308)
 3: (174,129) (292,222)
 4: (232,172) (176,136)
 5: (290,215) ( 60, 50)
Test finished
```

Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>

boards/risc-v/qemu-rv/rv-virt/configs/kfb64/defconfig

@@ -0,0 +1,109 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_DISABLE_OS_API is not set
+# CONFIG_NSH_DISABLE_LOSMART is not set
+CONFIG_16550_ADDRWIDTH=0
+CONFIG_16550_UART0=y
+CONFIG_16550_UART0_BASE=0x10000000
+CONFIG_16550_UART0_CLOCK=3686400
+CONFIG_16550_UART0_IRQ=35
+CONFIG_16550_UART0_SERIAL_CONSOLE=y
+CONFIG_16550_UART=y
+CONFIG_ALLOW_BSD_COMPONENTS=y
+CONFIG_ARCH="risc-v"
+CONFIG_ARCH_ADDRENV=y
+CONFIG_ARCH_BOARD="rv-virt"
+CONFIG_ARCH_BOARD_QEMU_RV_VIRT=y
+CONFIG_ARCH_CHIP="qemu-rv"
+CONFIG_ARCH_CHIP_QEMU_RV64=y
+CONFIG_ARCH_CHIP_QEMU_RV=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_A=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_C=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_M=y
+CONFIG_ARCH_DATA_NPAGES=128
+CONFIG_ARCH_DATA_VBASE=0xC0100000
+CONFIG_ARCH_HEAP_NPAGES=128
+CONFIG_ARCH_HEAP_VBASE=0xC0200000
+CONFIG_ARCH_INTERRUPTSTACK=2048
+CONFIG_ARCH_KERNEL_STACKSIZE=3072
+CONFIG_ARCH_PGPOOL_MAPPING=y
+CONFIG_ARCH_PGPOOL_PBASE=0x80400000
+CONFIG_ARCH_PGPOOL_SIZE=4194304
+CONFIG_ARCH_PGPOOL_VBASE=0x80400000
+CONFIG_ARCH_RISCV=y
+CONFIG_ARCH_SHM_NPAGES=512
+CONFIG_ARCH_SHM_VBASE=0xC2000000
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_ARCH_TEXT_NPAGES=128
+CONFIG_ARCH_TEXT_VBASE=0xC0000000
+CONFIG_ARCH_USE_MMU=y
+CONFIG_ARCH_USE_MPU=y
+CONFIG_ARCH_USE_S_MODE=y
+CONFIG_BINFMT_ELF_EXECUTABLE=y
+CONFIG_BOARD_LOOPSPERMSEC=6366
+CONFIG_BUILD_KERNEL=y
+CONFIG_DEBUG_ASSERTIONS=y
+CONFIG_DEBUG_FEATURES=y
+CONFIG_DEBUG_FULLOPT=y
+CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DEV_SIMPLE_ADDRENV=y
+CONFIG_DEV_ZERO=y
+CONFIG_DRIVERS_VIDEO=y
+CONFIG_DRIVERS_VIRTIO=y
+CONFIG_DRIVERS_VIRTIO_GPU=y
+CONFIG_DRIVERS_VIRTIO_MMIO=y
+CONFIG_DRIVERS_VIRTIO_SERIAL=y
+CONFIG_ELF=y
+CONFIG_EXAMPLES_FB=y
+CONFIG_EXAMPLES_HELLO=y
+CONFIG_FS_HOSTFS=y
+CONFIG_FS_LARGEFILE=y
+CONFIG_FS_PROCFS=y
+CONFIG_IDLETHREAD_STACKSIZE=3072
+CONFIG_INIT_FILEPATH="/system/bin/init"
+CONFIG_INIT_MOUNT=y
+CONFIG_INIT_MOUNT_DATA="fs=../apps"
+CONFIG_INIT_MOUNT_FLAGS=0x1
+CONFIG_INIT_MOUNT_FSTYPE="hostfs"
+CONFIG_INIT_MOUNT_SOURCE=""
+CONFIG_INIT_MOUNT_TARGET="/system"
+CONFIG_INIT_STACKSIZE=3072
+CONFIG_LIBC_ENVPATH=y
+CONFIG_LIBC_EXECFUNCS=y
+CONFIG_LIBC_PERROR_STDOUT=y
+CONFIG_LIBC_STRERROR=y
+CONFIG_LIBM=y
+CONFIG_MEMSET_64BIT=y
+CONFIG_MEMSET_OPTSPEED=y
+CONFIG_MM_PGALLOC=y
+CONFIG_NFILE_DESCRIPTORS_PER_BLOCK=6
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_FILE_APPS=y
+CONFIG_NSH_READLINE=y
+CONFIG_PATH_INITIAL="/system/bin"
+CONFIG_RAM_SIZE=33554432
+CONFIG_RAM_START=0x80000000
+CONFIG_RAM_VSTART=0x80000000
+CONFIG_READLINE_CMD_HISTORY=y
+CONFIG_RISCV_SEMIHOSTING_HOSTFS=y
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_HPWORK=y
+CONFIG_SCHED_LPWORK=y
+CONFIG_SCHED_WAITPID=y
+CONFIG_SERIAL_UART_ARCH_MMIO=y
+CONFIG_STACK_COLORATION=y
+CONFIG_START_DAY=2
+CONFIG_START_MONTH=11
+CONFIG_START_YEAR=2022
+CONFIG_SYMTAB_ORDEREDBYNAME=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_SYSTEM_NSH_PROGNAME="init"
+CONFIG_TESTING_GETPRIME=y
+CONFIG_TESTING_OSTEST=y
+CONFIG_VIDEO_FB=y

drivers/video/Kconfig

@@ -49,6 +49,7 @@ if DRIVERS_VIDEO
 config VIDEO_FB
 	bool "Framebuffer character driver"
 	default n
+	select ARCH_VMA_MAPPING if BUILD_KERNEL
 
 config VIDEO_FB_NPOLLWAITERS
 	int "Video fb poll count of each open structure"

drivers/video/fb.c

@@ -1032,7 +1032,12 @@ static int fb_mmap(FAR struct file *filep, FAR struct mm_map_entry_s *map)
   if (map->offset >= 0 && map->offset < panelinfo.fblen &&
       map->length && map->offset + map->length <= panelinfo.fblen)
     {
+#ifdef CONFIG_BUILD_KERNEL
+      map->vaddr = vm_map_region((uintptr_t)panelinfo.fbmem + map->offset,
+                                 panelinfo.fblen);
+#else
       map->vaddr = (FAR char *)panelinfo.fbmem + map->offset;
+#endif
       return OK;
     }