xilinx: versal: add firmware access to PMC multi Boot mode register
Added extended support for retrieving the PMC muti boot mode
register via the firmware interface, which is preferred when
U-Boot runs in EL2 and cannot directly access PMC registers
via raw reads. Ideally, all secure registers should be accessed
via xilinx_pm_request(). Introduced the secure
zynqmp_pm_get_pmc_multi_boot_reg() call, which uses
xilinx_pm_request() to read the PMC multi boot mode register.
BootROM increments the MultiBoot register (PMC_MULTI_BOOT) read
address offset by 32 KB and retries. For SD and eMMC boot modes,
it can search up to 8191 FAT files for the identification string.
A 13-bit mask (0x1FFF) is applied to PMC_MULTI_BOOT_MASK to obtain
the correct values in BootROM.
Signed-off-by: Prasad Kummari <prasad.kummari@amd.com>
Link: https://lore.kernel.org/r/20250305134845.3182193-1-prasad.kummari@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/board/xilinx/versal/board.c b/board/xilinx/versal/board.c
index f6cf3c2..8ea9eee 100644
--- a/board/xilinx/versal/board.c
+++ b/board/xilinx/versal/board.c
@@ -61,12 +61,18 @@
static u32 versal_multi_boot(void)
{
u8 bootmode = versal_get_bootmode();
+ u32 reg = 0;
/* Mostly workaround for QEMU CI pipeline */
if (bootmode == JTAG_MODE)
return 0;
- return readl(0xF1110004);
+ if (IS_ENABLED(CONFIG_ZYNQMP_FIRMWARE) && current_el() != 3)
+ reg = zynqmp_pm_get_pmc_multi_boot_reg();
+ else
+ reg = readl(PMC_MULTI_BOOT_REG);
+
+ return reg & PMC_MULTI_BOOT_MASK;
}
int board_init(void)