Hi Sascha, I've been playing with passing some data from first to second stage using Jan's patches. It worked fine, but in my case I want to store this data on a global variable, which is cleared as it's in the BSS. There is a clean workarround to this issue?
Thanks, Vicente. On Wed, Sep 26, 2012 at 9:45 AM, Sascha Hauer <s.ha...@pengutronix.de>wrote: > On Wed, Sep 26, 2012 at 12:59:51AM +0200, vj wrote: > > --- > > arch/arm/cpu/cpu.c | 1 + > > arch/arm/lib/barebox.lds.S | 10 + > > arch/arm/mach-omap/Kconfig | 21 + > > arch/arm/mach-omap/Makefile | 1 + > > arch/arm/mach-omap/include/mach/omap4_rom_usb.h | 146 +++++ > > arch/arm/mach-omap/omap4_generic.c | 2 + > > arch/arm/mach-omap/omap4_rom_usb.c | 189 ++++++ > > arch/arm/mach-omap/xload.c | 26 + > > scripts/.gitignore | 1 + > > scripts/Makefile | 3 + > > scripts/usbboot.c | 797 > ++++++++++++++++++++++++ > > 11 files changed, 1197 insertions(+) > > create mode 100644 arch/arm/mach-omap/include/mach/omap4_rom_usb.h > > create mode 100644 arch/arm/mach-omap/omap4_rom_usb.c > > create mode 100644 scripts/usbboot.c > > > > diff --git a/arch/arm/cpu/cpu.c b/arch/arm/cpu/cpu.c > > index 71ef8c0..05343de 100644 > > --- a/arch/arm/cpu/cpu.c > > +++ b/arch/arm/cpu/cpu.c > > @@ -89,6 +89,7 @@ void arch_shutdown(void) > > : "r0", "r1", "r2", "r3", "r6", "r10", "r12", "lr", "cc", > "memory" > > ); > > #endif > > + __asm__ __volatile__ ("cpsid i\n"); > > } > > > > #ifdef CONFIG_THUMB2_BAREBOX > > diff --git a/arch/arm/lib/barebox.lds.S b/arch/arm/lib/barebox.lds.S > > index a69013f..ff7b63d 100644 > > --- a/arch/arm/lib/barebox.lds.S > > +++ b/arch/arm/lib/barebox.lds.S > > @@ -97,6 +97,16 @@ SECTIONS > > __bss_start = .; > > .bss : { *(.bss*) } > > __bss_stop = .; > > +#ifdef CONFIG_SHARE_USB_HANDLE > > + /* > > + * Reserve space for the USB handle > > + */ > > + . = CONFIG_USB_HANDLE_HANDOVER; > > + . = ALIGN(4); > > + __usb_handle = .; > > + /* . += sizeof(struct usb); */ > > + . += 84; > > +#endif > > If I understand correctly the first stage loader puts some data here > where a second stage barebox (configured with the same value for > CONFIG_USB_HANDLE_HANDOVER) will pick it up. > > This seems to be a bit fragile. Fortunately Jan has posted a series > that gives the control of the reset vector to the boards, which means > that both stages do not have to agree on an addres, but instead a > pointer can be passed from the first to the second stage. > > > +int usb_open(void) > > So this uses the OMAP4 ROM to do USB communication, right? The functions > should have a omap_rom_* prefix then, otherwise it's not clear for a > reader which context these functions have. > > The calling of the ROM code btw explains why the setting of VBAR breaks > USB boot. The ROM probably uses the vectors. > > > + > > + n = rom_get_per_driver(&pusb->io, boot->device_type); > > + if (n) > > + return n; > > + > > + pusb->dread.xfer_mode = boot->xfer_mode; > > + pusb->dread.options = boot->options; > > + pusb->dread.device_type = boot->device_type; > > + > > + pusb->dwrite.xfer_mode = boot->xfer_mode; > > + pusb->dwrite.options = boot->options; > > + pusb->dwrite.device_type = boot->device_type; > > +#else > > +#ifdef CONFIG_MMU > > +#error USB communications not working under MMU > > You can add the following to CONFIG_OMAP4_USB_BOOT instead: > > depends on !MMU > > So that an invalid config is not allowed in the first place. > > > > diff --git a/scripts/usbboot.c b/scripts/usbboot.c > > This should also be named omap4-usbboot.c, or maybe, if the works on > other OMAPs, just omap-usboot.c > > Sascha > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >
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