[PATCH 4/4] arm/raspberrypi: add VideoCore framebuffer without initialization

Alan Cudmore alan.cudmore at gmail.com
Sat Apr 30 15:30:14 UTC 2016


I applied the 4 patches ( I had to use the “patch” command, I could not get “git apply” to work for some reason ) 
It runs on the Raspberry Pi A+ ( 256MB RAM, single core ) , but it did not boot on the Raspberry Pi 2. I commented out the calls to rpi_init_cmdline() and it booted on the Pi 2 again.

I will try to troubleshoot more as soon as I can.

Alan

> On Apr 28, 2016, at 7:29 AM, Pavel Pisa <ppisa4lists at pikron.com> wrote:
> 
> From: YANG Qiao <yangqiao0505 at me.com>
> Date: Thu, 13 Aug 2015 00:06:10 +0200
> 
> ---
> c/src/lib/libbsp/arm/raspberrypi/Makefile.am  |   1 +
> c/src/lib/libbsp/arm/raspberrypi/console/fb.c | 331 ++++++++++++++++++++++++++
> 2 files changed, 332 insertions(+)
> create mode 100644 c/src/lib/libbsp/arm/raspberrypi/console/fb.c
> 
> diff --git a/c/src/lib/libbsp/arm/raspberrypi/Makefile.am b/c/src/lib/libbsp/arm/raspberrypi/Makefile.am
> index 258f8a0..77935dc 100644
> --- a/c/src/lib/libbsp/arm/raspberrypi/Makefile.am
> +++ b/c/src/lib/libbsp/arm/raspberrypi/Makefile.am
> @@ -114,6 +114,7 @@ libbsp_a_SOURCES += ../../shared/console_select.c
> libbsp_a_SOURCES += ../../shared/console_write.c
> libbsp_a_SOURCES += console/console-config.c
> libbsp_a_SOURCES += console/usart.c
> +libbsp_a_SOURCES += console/fb.c
> 
> # Mailbox
> libbsp_a_SOURCES += misc/mailbox.c
> diff --git a/c/src/lib/libbsp/arm/raspberrypi/console/fb.c b/c/src/lib/libbsp/arm/raspberrypi/console/fb.c
> new file mode 100644
> index 0000000..a83d560
> --- /dev/null
> +++ b/c/src/lib/libbsp/arm/raspberrypi/console/fb.c
> @@ -0,0 +1,331 @@
> +/**
> + * @file
> + *
> + * @ingroup raspberrypi
> + *
> + * @brief framebuffer support.
> + */
> +
> +/*
> + * Copyright (c) 2015 Yang Qiao
> + *
> + *  The license and distribution terms for this file may be
> + *  found in the file LICENSE in this distribution or at
> + *
> + *  http://www.rtems.org/license/LICENSE
> + *
> + */
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <errno.h>
> +#include <sys/types.h>
> +
> +#include <bsp.h>
> +#include <bsp/raspberrypi.h>
> +#include <bsp/mailbox.h>
> +#include <bsp/vc.h>
> +
> +#include <rtems.h>
> +#include <rtems/libio.h>
> +#include <rtems/fb.h>
> +#include <rtems/framebuffer.h>
> +#include <rtems/score/atomic.h>
> +
> +#define SCREEN_WIDTH 1024
> +#define SCREEN_HEIGHT 768
> +#define BPP 32
> +#define BUFFER_SIZE (SCREEN_WIDTH*SCREEN_HEIGHT*BPP/8)
> +
> +/* flag to limit driver to protect against multiple opens */
> +static Atomic_Flag driver_mutex;
> +
> +/*
> + * screen information for the driver (fb0).
> + */
> +
> +static struct fb_var_screeninfo fb_var_info = {
> +  .xres                = SCREEN_WIDTH,
> +  .yres                = SCREEN_HEIGHT,
> +  .bits_per_pixel      = BPP
> +};
> +
> +static struct fb_fix_screeninfo fb_fix_info = {
> +  .smem_start          = (void *) NULL,
> +  .smem_len            = 0,
> +  .type                = FB_TYPE_PACKED_PIXELS,
> +  .visual              = FB_VISUAL_TRUECOLOR,
> +  .line_length         = 0
> +};
> +
> +int raspberrypi_get_fix_screen_info( struct fb_fix_screeninfo *info )
> +{
> +  *info = fb_fix_info;
> +  return 0;
> +}
> +
> +int raspberrypi_get_var_screen_info( struct fb_var_screeninfo *info )
> +{
> +  *info = fb_var_info;
> +  return 0;
> +}
> +
> +static int
> +find_mode_from_cmdline(void)
> +{
> +  const char* opt;
> +  char* endptr;
> +  uint32_t width;
> +  uint32_t height;
> +  uint32_t bpp;
> +  opt = rpi_cmdline_arg("--video=");
> +  if (opt)
> +  {
> +      opt += sizeof("--video=")-1;
> +      width = strtol(opt, &endptr, 10);
> +      if (*endptr != 'x')
> +      {
> +          return -2;
> +      }
> +      opt = endptr+1;
> +      height = strtol(opt, &endptr, 10);
> +      switch (*endptr)
> +      {
> +          case '-':
> +              opt = endptr+1;
> +              if (strlen(opt) <= 2)
> +                  bpp = strtol(opt, &endptr, 10);
> +              else
> +              {
> +                  bpp = strtol(opt, &endptr, 10);
> +                  if (*endptr != ' ')
> +                  {
> +                      return -4;
> +                  }
> +              }
> +          case ' ':
> +          case 0:
> +              break;
> +          default:
> +              return -3;
> +      }
> +  }
> +  else
> +    return -1;
> +
> +  fb_var_info.xres    = width;
> +  fb_var_info.yres    = height;
> +
> +  return 0;
> +}
> +
> +static int
> +find_mode_from_vc(void)
> +{
> +  bcm2835_get_display_size_entries entries;
> +  bcm2835_mailbox_get_display_size(&entries);
> +  unsigned int width = entries.width;
> +  unsigned int height = entries.height;
> +
> +  if (width == 0 || height == 0)
> +  {
> +    fb_var_info.xres    = SCREEN_WIDTH;
> +    fb_var_info.yres    = SCREEN_HEIGHT;
> +  }
> +  else
> +  {
> +    fb_var_info.xres     = width;
> +    fb_var_info.yres     = height;
> +  }
> +
> +  return 0;
> +}
> +
> +static bool
> +hdmi_is_present(void)
> +{
> +  bcm2835_get_display_size_entries entries;
> +  bcm2835_mailbox_get_display_size(&entries);
> +  if(entries.width == 0x290 && entries.height ==0x1A0 )
> +  {
> +    return false;
> +  }
> +  else
> +  {
> +    return true;
> +  }
> +}
> +
> +int
> +fb_init(void)
> +{
> +  if (fb_fix_info.smem_start != NULL)
> +  {
> +    return -2;
> +  }
> +
> +  if (hdmi_is_present() == false)
> +  {
> +    return -3;
> +  }
> +
> +  if (find_mode_from_cmdline())
> +  {
> +    if(find_mode_from_vc())
> +      return -1;
> +  }
> +
> +  bcm2835_init_frame_buffer_entries  init_frame_buffer_entries;
> +  init_frame_buffer_entries.xres = fb_var_info.xres;
> +  init_frame_buffer_entries.yres = fb_var_info.yres;
> +  init_frame_buffer_entries.xvirt = fb_var_info.xres;
> +  init_frame_buffer_entries.yvirt = fb_var_info.yres;
> +  init_frame_buffer_entries.depth = fb_var_info.bits_per_pixel;
> +  init_frame_buffer_entries.pixel_order = bcm2835_mailbox_pixel_order_rgb;
> +  init_frame_buffer_entries.alpha_mode = bcm2835_mailbox_alpha_mode_0_opaque;
> +  init_frame_buffer_entries.voffset_x = 0;
> +  init_frame_buffer_entries.voffset_y = 0;
> +  init_frame_buffer_entries.overscan_left = 0;
> +  init_frame_buffer_entries.overscan_right = 0;
> +  init_frame_buffer_entries.overscan_top = 0;
> +  init_frame_buffer_entries.overscan_bottom = 0;
> +  bcm2835_mailbox_init_frame_buffer(&init_frame_buffer_entries);
> +
> +  bcm2835_get_pitch_entries get_pitch_entries;
> +  bcm2835_mailbox_get_pitch(&get_pitch_entries);
> +
> +  fb_var_info.xres = init_frame_buffer_entries.xres;
> +  fb_var_info.yres = init_frame_buffer_entries.yres;
> +  fb_var_info.bits_per_pixel = init_frame_buffer_entries.depth;
> +  fb_fix_info.smem_start = init_frame_buffer_entries.base;
> +  fb_fix_info.smem_len = init_frame_buffer_entries.size;
> +  fb_fix_info.line_length = get_pitch_entries.pitch;
> +
> +  return 0;
> +}
> +
> +
> +/*
> + * fbds device driver initialize entry point.
> + */
> +
> +rtems_device_driver
> +frame_buffer_initialize (rtems_device_major_number major,
> +                 rtems_device_minor_number minor, void *arg)
> +{
> +  rtems_status_code status;
> +
> +  /* register the devices */
> +  status = rtems_io_register_name (FRAMEBUFFER_DEVICE_0_NAME, major, 0);
> +  if (status != RTEMS_SUCCESSFUL) {
> +    printk ("[!] error registering framebuffer\n");
> +    rtems_fatal_error_occurred (status);
> +  }
> +  _Atomic_Flag_clear(&driver_mutex, ATOMIC_ORDER_RELEASE);
> +  return RTEMS_SUCCESSFUL;
> +}
> +
> +/*
> + * fbds device driver open operation.
> + */
> +
> +rtems_device_driver
> +frame_buffer_open (rtems_device_major_number major,
> +           rtems_device_minor_number minor, void *arg)
> +{
> +  if (_Atomic_Flag_test_and_set(&driver_mutex, ATOMIC_ORDER_ACQUIRE) != 0 ) {
> +    printk( "FB_CIRRUS could not lock driver_mutex\n" );
> +    return RTEMS_UNSATISFIED;
> +  }
> +
> +  memset ((void *)fb_fix_info.smem_start, 0, fb_fix_info.smem_len);
> +  return RTEMS_SUCCESSFUL;
> +}
> +
> +/*
> + * fbds device driver close operation.
> + */
> +
> +rtems_device_driver
> +frame_buffer_close (rtems_device_major_number major,
> +            rtems_device_minor_number minor, void *arg)
> +{
> +  /* restore previous state.  for VGA this means return to text mode.
> +   * leave out if graphics hardware has been initialized in
> +   * frame_buffer_initialize() */
> +  _Atomic_Flag_clear(&driver_mutex, ATOMIC_ORDER_RELEASE);
> +  memset ((void *)fb_fix_info.smem_start, 0, fb_fix_info.smem_len);
> +  return RTEMS_SUCCESSFUL;
> +}
> +
> +/*
> + * fbds device driver read operation.
> + */
> +
> +rtems_device_driver
> +frame_buffer_read (rtems_device_major_number major,
> +           rtems_device_minor_number minor, void *arg)
> +{
> +  rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
> +  rw_args->bytes_moved =
> +    ((rw_args->offset + rw_args->count) > fb_fix_info.smem_len ) ?
> +    (fb_fix_info.smem_len - rw_args->offset) :rw_args->count;
> +  memcpy( rw_args->buffer,
> +          (const void *) (fb_fix_info.smem_start + rw_args->offset),
> +          rw_args->bytes_moved);
> +  return RTEMS_SUCCESSFUL;
> +}
> +
> +/*
> + * fbds device driver write operation.
> + */
> +
> +rtems_device_driver
> +frame_buffer_write (rtems_device_major_number major,
> +            rtems_device_minor_number minor, void *arg)
> +{
> +  rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
> +  rw_args->bytes_moved =
> +    ((rw_args->offset + rw_args->count) > fb_fix_info.smem_len ) ?
> +    (fb_fix_info.smem_len - rw_args->offset) : rw_args->count;
> +  memcpy( (void *) (fb_fix_info.smem_start + rw_args->offset),
> +          rw_args->buffer,
> +          rw_args->bytes_moved);
> +  return RTEMS_SUCCESSFUL;
> +}
> +
> +/*
> + * ioctl entry point.
> + */
> +
> +rtems_device_driver
> +frame_buffer_control (rtems_device_major_number major,
> +              rtems_device_minor_number minor, void *arg)
> +{
> +  rtems_libio_ioctl_args_t *args = arg;
> +
> +  /* XXX check minor */
> +
> +  switch (args->command) {
> +  case FBIOGET_VSCREENINFO:
> +    memcpy (args->buffer, &fb_var_info, sizeof (fb_var_info));
> +    args->ioctl_return = 0;
> +    break;
> +  case FBIOGET_FSCREENINFO:
> +    memcpy (args->buffer, &fb_fix_info, sizeof (fb_fix_info));
> +    args->ioctl_return = 0;
> +    break;
> +  case FBIOGETCMAP:
> +    args->ioctl_return = 0;
> +    break;
> +  case FBIOPUTCMAP:
> +    args->ioctl_return = 0;
> +    break;
> +
> +  default:
> +    args->ioctl_return = 0;
> +    break;
> +
> +  }
> +  return RTEMS_SUCCESSFUL;
> +}
> -- 
> 1.9.1
> 



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