[U-Boot] [PATCH v4 4/5] arm: socfpga: fix SPL booting from fpga OnChip RAM

[Simon Goldschmidt]

To boot from fpga OnChip RAM, some changes are required in SPL
to ensure the code is linked to the correct address (in contrast
to QSPI and MMC boot, FPGA boot executes SPL in place instead of
copying it to SRAM) and that fpga OnChip RAM stays accessible while
SPL runs (don't disable fpga bridges).

This adds a new config option (CONFIG_SPL_SOCFPGA_BOOT_FROM_FPGA)
for socfpga gen5 boards.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
---

Changes in v4: Adapted to changed previous patch
Changes in v3: this patch is new in v3
Changes in v2: None

 arch/arm/mach-socfpga/Kconfig     | 12 ++++++++++++
 arch/arm/mach-socfpga/misc_gen5.c | 11 +++++++++--
 arch/arm/mach-socfpga/spl_gen5.c  |  6 ++++--
 include/configs/socfpga_common.h  |  5 +++++
 4 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 5c1df2cf1f..a909395aac 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -132,3 +132,15 @@ config SYS_CONFIG_NAME
 	default "socfpga_vining_fpga" if TARGET_SOCFPGA_SAMTEC_VINING_FPGA
 
 endif
+
+if TARGET_SOCFPGA_GEN5
+
+config SPL_SOCFPGA_BOOT_FROM_FPGA
+	bool "Allow booting SPL from FPGA OnChip RAM"
+	default n
+	help
+	  Boot from FPGA: this changes the linker address for SPL code to run
+	  from FPGA OnChip memory instead of SRAM and ensures FPGA OnChip RAM
+	  stays accessible while SPL runs.
+
+endif
diff --git a/arch/arm/mach-socfpga/misc_gen5.c b/arch/arm/mach-socfpga/misc_gen5.c
index 429c3d6cd5..c82c3584dc 100644
--- a/arch/arm/mach-socfpga/misc_gen5.c
+++ b/arch/arm/mach-socfpga/misc_gen5.c
@@ -187,7 +187,13 @@ void socfpga_sdram_remap_zero(void)
 	setbits_le32(&scu_regs->sacr, 0xfff);
 
 	/* Configure the L2 controller to make SDRAM start at 0 */
-	writel(0x1, &nic301_regs->remap);	/* remap.mpuzero */
+	if (CONFIG_IS_ENABLED(SOCFPGA_BOOT_FROM_FPGA)) {
+		/* remap.mpuzero, keep fpga bridge enabled */
+		writel(0x9, &nic301_regs->remap);
+	} else {
+		/* remap.mpuzero */
+		writel(0x1, &nic301_regs->remap);
+	}
 	writel(0x1, &pl310->pl310_addr_filter_start);
 }
 
@@ -209,7 +215,8 @@ int arch_early_init_r(void)
 	for (i = 0; i < 8; i++)	/* Cache initial SW setting regs */
 		iswgrp_handoff[i] = readl(&sysmgr_regs->iswgrp_handoff[i]);
 
-	socfpga_bridges_reset(1);
+	if (!CONFIG_IS_ENABLED(SOCFPGA_BOOT_FROM_FPGA))
+		socfpga_bridges_reset(1);
 
 	socfpga_sdram_remap_zero();
 
diff --git a/arch/arm/mach-socfpga/spl_gen5.c b/arch/arm/mach-socfpga/spl_gen5.c
index be318cc0d9..0c7f6a8c84 100644
--- a/arch/arm/mach-socfpga/spl_gen5.c
+++ b/arch/arm/mach-socfpga/spl_gen5.c
@@ -93,7 +93,8 @@ void board_init_f(ulong dummy)
 	/* Put everything into reset but L4WD0. */
 	socfpga_per_reset_all();
 	/* Put FPGA bridges into reset too. */
-	socfpga_bridges_reset(1);
+	if (!CONFIG_IS_ENABLED(SOCFPGA_BOOT_FROM_FPGA))
+		socfpga_bridges_reset(1);
 
 	socfpga_per_reset(SOCFPGA_RESET(SDR), 0);
 	socfpga_per_reset(SOCFPGA_RESET(UART0), 0);
@@ -163,5 +164,6 @@ void board_init_f(ulong dummy)
 		hang();
 	}
 
-	socfpga_bridges_reset(1);
+	if (!CONFIG_IS_ENABLED(SOCFPGA_BOOT_FROM_FPGA))
+		socfpga_bridges_reset(1);
 }
diff --git a/include/configs/socfpga_common.h b/include/configs/socfpga_common.h
index d1148b838b..99c5e39086 100644
--- a/include/configs/socfpga_common.h
+++ b/include/configs/socfpga_common.h
@@ -239,7 +239,12 @@ unsigned int cm_get_qspi_controller_clk_hz(void);
  * 0xFFEz_zzzz ...... Malloc area (grows up to top)
  * 0xFFE3_FFFF ...... End of SRAM (top)
  */
+#if CONFIG_SPL_SOCFPGA_BOOT_FROM_FPGA
+/* SPL executed from FPGA */
+#define CONFIG_SPL_TEXT_BASE		0xC0000000
+#else
 #define CONFIG_SPL_TEXT_BASE		CONFIG_SYS_INIT_RAM_ADDR
+#endif
 #define CONFIG_SPL_MAX_SIZE		CONFIG_SYS_INIT_RAM_SIZE
 
 #if defined(CONFIG_TARGET_SOCFPGA_ARRIA10)
-- 
2.17.1