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authorSean Anderson <[email protected]>2024-02-22 15:05:11 -0500
committerMichal Simek <[email protected]>2024-03-01 08:32:51 +0100
commit2768a769a2634eb477915a3eb08cc381e8c05c5b (patch)
tree3483da5a0c465d71f4f829bad009b4c9d9d70300
parentabd4fb5ac13215733569925a06991e0a182ede14 (diff)
arm64: zynqmp: Support semihosting boot method
Currently, when we boot from JTAG we try to boot U-Boot from RAM. However, this is a bit tricky to time, since the debugger has to wait for SPL to initialize RAM before it can load U-Boot. This can result in long waits, since occasionally initializing RAM (and other things in psu_init) takes a long time to complete and the debugger must wait for this worst case. Support semihosting if it is enabled, as it lets U-Boot tell the debugger when we are ready for the image. This means we don't have to wait any more than necessary. We don't change the default config to ensure we don't break compatibility with existing debuggers that don't expect us to hit semihosting breakpoints. Signed-off-by: Sean Anderson <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Michal Simek <[email protected]>
-rw-r--r--arch/arm/mach-zynqmp/spl.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/arm/mach-zynqmp/spl.c b/arch/arm/mach-zynqmp/spl.c
index a0f35f36faa..5af735aa5ce 100644
--- a/arch/arm/mach-zynqmp/spl.c
+++ b/arch/arm/mach-zynqmp/spl.c
@@ -9,6 +9,7 @@
#include <image.h>
#include <init.h>
#include <log.h>
+#include <semihosting.h>
#include <spl.h>
#include <linux/delay.h>
@@ -66,6 +67,11 @@ void spl_board_init(void)
}
#endif
+static u32 jtag_boot_device(void)
+{
+ return semihosting_enabled() ? BOOT_DEVICE_SMH : BOOT_DEVICE_RAM;
+}
+
void board_boot_order(u32 *spl_boot_list)
{
spl_boot_list[0] = spl_boot_device();
@@ -75,7 +81,7 @@ void board_boot_order(u32 *spl_boot_list)
if (spl_boot_list[0] == BOOT_DEVICE_MMC2)
spl_boot_list[1] = BOOT_DEVICE_MMC1;
- spl_boot_list[2] = BOOT_DEVICE_RAM;
+ spl_boot_list[2] = jtag_boot_device();
}
u32 spl_boot_device(void)
@@ -97,7 +103,7 @@ u32 spl_boot_device(void)
switch (bootmode) {
case JTAG_MODE:
- return BOOT_DEVICE_RAM;
+ return jtag_boot_device();
#ifdef CONFIG_SPL_MMC
case SD_MODE1:
case SD1_LSHFT_MODE: /* not working on silicon v1 */