On 28 August 2014 17:28, Michal Simek michal.simek@xilinx.com wrote:
On 08/28/2014 01:02 PM, Peter Crosthwaite wrote:
Ping!
On Wed, Aug 20, 2014 at 10:14 PM, Peter Crosthwaite crosthwaitepeter@gmail.com wrote:
To better enable debug of u-boot itself (in particular SPL). To debug u-boot you want to put your board in JTAG boot mode for quick recompile and elf downloads via the JTAG debugger. Yet you may still want to boot from a persistent storage media (SD or QSPI). Allow override of the boot mode pins to facilitate this.
Signed-off-by: Peter Crosthwaite crosthwaite.peter@gmail.com
arch/arm/cpu/armv7/zynq/slcr.c | 4 ++++ doc/README.zynq | 6 ++++++ 2 files changed, 10 insertions(+)
diff --git a/arch/arm/cpu/armv7/zynq/slcr.c b/arch/arm/cpu/armv7/zynq/slcr.c index 934ccc3..26e02b8 100644 --- a/arch/arm/cpu/armv7/zynq/slcr.c +++ b/arch/arm/cpu/armv7/zynq/slcr.c @@ -155,8 +155,12 @@ void zynq_slcr_devcfg_enable(void)
u32 zynq_slcr_get_boot_mode(void) { +#ifdef CONFIG_ZYNQ_BM_FORCE
return CONFIG_ZYNQ_BM_FORCE;+#else /* Get the bootmode register value */ return readl(&slcr_base->boot_mode); +#endif }
u32 zynq_slcr_get_idcode(void) diff --git a/doc/README.zynq b/doc/README.zynq index 043c970..70be7ae 100644 --- a/doc/README.zynq +++ b/doc/README.zynq @@ -52,6 +52,12 @@ board_late_init() will read the bootmode values using slcr bootmode register at runtime and assign the modeboot variable to specific bootmode string which is intern used in autoboot.
+This value can be overridden at compile time with the define +CONFIG_ZYNQ_BM_FORCE. This is useful for debugging a u-boot elf downloaded +over JTAG. E.g. The board will be jumpered for ZYNQ_BM_JTAG, but you can +force u-boot to attempt an SD or QSPI boot should that be what you want to +debug.
I understand the purpose of this patch but I don't think it is useful to add and support this option. Someone else could come with reading GPIO for this purpose, etc which is just the same case.
I am happy to add the patch which shows bootmode register content or any ? : logic around in debug() print but adding new CONFIG_ option is just too much. (Also every new config option should be properly documented).
The second option is to setup spl_boot_device in arch zynq as weak function and overwrite it. Then you can setup whatever you like in your board file.
Agreed with Michal, this looks hack to macro, where u can get different elf for with and without that macro.
May be we can add one env like "zynq_bm_force" on ENV_SETTINGS of our board file for selecting the respective bootmode at runtime.
thanks!