[PATCH 1/3] mmc: fsl_esdhc_spl: Add support for loading proper U-Boot from unaligned location

Pali Rohár
2022-05-11T19:33:11Z

This allows to concatenate SPL and proper U-Boot without extra alignment.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
drivers/mmc/fsl_esdhc_spl.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/fsl_esdhc_spl.c b/drivers/mmc/fsl_esdhc_spl.c
index 760f13d24018..e3175de16bab 100644
--- a/drivers/mmc/fsl_esdhc_spl.c
+++ b/drivers/mmc/fsl_esdhc_spl.c
@@ -155,10 +155,21 @@ again:
* Load U-Boot image from mmc into RAM
*/
code_len = CONFIG_SYS_MMC_U_BOOT_SIZE;
- blk_start = ALIGN(offset, mmc->read_bl_len) / mmc->read_bl_len;
- blk_cnt = ALIGN(code_len, mmc->read_bl_len) / mmc->read_bl_len;
+ blk_start = offset / mmc->read_bl_len;
+ blk_off = offset % mmc->read_bl_len;
+ blk_cnt = ALIGN(code_len, mmc->read_bl_len) / mmc->read_bl_len + 1;
+ if (blk_off) {
+ err = mmc->block_dev.block_read(&mmc->block_dev,
+ blk_start, 1, tmp_buf);
+ if (err != 1) {
+ puts("spl: mmc read failed!!\n");
+ hang();
+ }
+ blk_start++;
+ }
err = mmc->block_dev.block_read(&mmc->block_dev, blk_start, blk_cnt,
- (uchar *)CONFIG_SYS_MMC_U_BOOT_DST);
+ (uchar *)CONFIG_SYS_MMC_U_BOOT_DST +
+ (blk_off ? (mmc->read_bl_len - blk_off) : 0));
if (err != blk_cnt) {
puts("spl: mmc read failed!!\n");
#ifndef CONFIG_FSL_CORENET
@@ -166,6 +177,14 @@ again:
#endif
hang();
}
+ /*
+ * SDHC DMA may erase bytes at dst + bl_len - blk_off - 8
+ * due to unaligned access. So copy leading bytes from tmp_buf
+ * after SDHC DMA transfer.
+ */
+ if (blk_off)
+ memcpy((uchar *)CONFIG_SYS_MMC_U_BOOT_DST,
+ tmp_buf + blk_off, mmc->read_bl_len - blk_off);

/*
* Clean d-cache and invalidate i-cache, to
--
2.20.1