[PATCH v3 3/3] mmc: fsl_esdhc_spl: Add support for builds without CONFIG_SYS_MMC_U_BOOT_OFFS

Pali Rohár
2022-08-05T20:10:53Z

When fixed offset via CONFIG_SYS_MMC_U_BOOT_OFFS is not specified then
expects that U-Boot proper is placed immediately after SPL without any
additional padding.

This allows to generate smaller SPL+U-Boot final binary as it is not
required to specify fixed offset to U-Boot proper at SPL compile time.

In this case offset to U-Boot proper is calculated at SPL compile time in
linker script.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
arch/powerpc/cpu/mpc85xx/u-boot-spl.lds | 10 ++++++++++
drivers/mmc/fsl_esdhc_spl.c | 8 ++++++++
2 files changed, 18 insertions(+)

diff --git a/arch/powerpc/cpu/mpc85xx/u-boot-spl.lds b/arch/powerpc/cpu/mpc85xx/u-boot-spl.lds
index 89df4b5f6f07..f775f6bc4d06 100644
--- a/arch/powerpc/cpu/mpc85xx/u-boot-spl.lds
+++ b/arch/powerpc/cpu/mpc85xx/u-boot-spl.lds
@@ -62,6 +62,13 @@ SECTIONS
__init_begin = .;
__init_end = .;
_end = .;
+
+#ifdef CONFIG_SYS_MPC85XX_NO_RESETVEC
+#if defined(CONFIG_SDCARD) && !defined(CONFIG_SYS_MMC_U_BOOT_OFFS)
+ mmc_u_boot_offs = .;
+#endif
+#endif
+
#ifdef CONFIG_SPL_SKIP_RELOCATE
. = ALIGN(4);
__bss_start = .;
@@ -94,6 +101,9 @@ SECTIONS
.resetvec IMAGE_TEXT_BASE + RESET_VECTOR_OFFSET : {
KEEP(*(.resetvec))
} = 0xffff
+#if defined(CONFIG_SDCARD) && !defined(CONFIG_SYS_MMC_U_BOOT_OFFS)
+ mmc_u_boot_offs = .;
+#endif
#endif

#ifndef CONFIG_SPL_SKIP_RELOCATE
diff --git a/drivers/mmc/fsl_esdhc_spl.c b/drivers/mmc/fsl_esdhc_spl.c
index dd6d5fa81ea6..aa00d7e2014d 100644
--- a/drivers/mmc/fsl_esdhc_spl.c
+++ b/drivers/mmc/fsl_esdhc_spl.c
@@ -9,6 +9,10 @@
#include <mmc.h>
#include <malloc.h>

+#ifndef CONFIG_SYS_MMC_U_BOOT_OFFS
+extern uchar mmc_u_boot_offs[];
+#endif
+
/*
* The environment variables are written to just after the u-boot image
* on SDCard, so we must read the MBR to get the start address and code
@@ -149,7 +153,11 @@ again:
val = *(tmp_buf + blk_off + ESDHC_BOOT_IMAGE_ADDR + i);
offset = (offset << 8) + val;
}
+#ifndef CONFIG_SYS_MMC_U_BOOT_OFFS
+ offset += (ulong)&mmc_u_boot_offs - CONFIG_SPL_TEXT_BASE;
+#else
offset += CONFIG_SYS_MMC_U_BOOT_OFFS;
+#endif
#endif
/*
* Load U-Boot image from mmc into RAM
--
2.20.1