[okl4-developer] qemu crashes if lcdcon1 is set to (0x1) - s3c2410 - gta01

[Dennis Gessner]

Hello everyone,
hello Nelson,

is there any reason, why qemu crashes if I set the lcdcon1-register to
0x1 (reading doc - a value of 0x1 means to "enable" the output??)?

I'm using a emulated gta01 inside qemu.

Here is what I did (similar to the "Tutorial: Using A Virtual Device"):

----
static int init_fb(struct ig_fb * fb, struct ig_lcd * lcd) {

    struct lcd_control_block *ctrl = lcd->control;
    fb->size = ctrl->xres * ctrl->yres / 8;
		// size of fb in bytes

    fb->ms = memsection_create_dma
	     (
	        fb->size,
	    	&fb->vbase,
	    	&fb->pm,
	    	L4_WriteThroughMemory
	      );
/* If the following is executed - qemu closes... Why??*/
    L4_KDB_Enter("Entering virtual_lcd_set_fb");
	virtual_lcd_set_fb(lcd->server, lcd->obj, fb->vbase, NULL);

    return 0;
}
----

inside "virtual_lcd_set_fb" (nearly at the end of the file
(./iguana/vlcd/src/lcd_server.c) there is a
"fb_set_buffer(lcd->fb, new_paddr);"

The following two functions come from
./drivers/s3c2410_lcd/src/s3c2410_lcd.c

----
static void fb_set_buffer_impl(struct fb_interface *fbi, struct
s3c2410_lcd *device, uintptr_t buff)
{
	fb_set_buffer_base(device, buff);
}

----
static void fb_set_buffer_base(struct s3c2410_lcd * device, uint32_t addr)
{
    //uint32_t    offsize   = OFFSET_AFTER_LINE;
//    uint32_t    pagewidth = X_RES * BITS_PER_PIXEL / BITS_PER_HWORD;
    //uint32_t    lcdbank   = addr >> 22 & ((1 << 9) - 1);
//    uint32_t    lcdbaseu  = (addr & ((1 << 22) - 1)) >> 1;
   // uint32_t    lcdbasel  = lcdbaseu + (pagewidth + offsize) * Y_RES;

    /*
     * XXX: should read previous bit value and restore that, instead
     *      assuming it should be set afterwards - nt
     */
	lcdcon1_set_envid(0x0);     /* clear ENVID */

//    lcdsaddr1_set_lcdbank(lcdbank);
//    lcdsaddr1_set_lcdbaseu(lcdbaseu);

    lcdsaddr1_write(addr>>1);

	lcdsaddr2_set_lcdbasel(
            (lcdsaddr1_read() & 0x1fffff) + 640*480
             );
//      lcdsaddr2_set_lcdbasel(   (addr+648*480*2)>>1);

//    lcdsaddr3_set_offsize(offsize);
    lcdsaddr3_set_pagewidth(480);


// After the next line - qemu crashes... Why?
    lcdcon1_set_envid(0x1);     /* set ENVID */

}
------
I start qemu with the following command:

"arm-softmmu/qemu-system-arm -M gta01 -m 130 -mtdblock flash.image
-kernel image.boot -usb -show-cursor -serial
telnet:localhost:1200,server -std-vga"

My next step will be to try this in real hardware - but I think this
will produce the same crash...

Any help would be very welcome.

Best regards,
Dennis