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.pe...@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.
+
SLCR bootmode register Bit[3:0] values
#define ZYNQ_BM_NOR 0x02
#define ZYNQ_BM_SD 0x05
--
1.9.1
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