[PATCH v2] mmc: fsl_esdhc_spl: Add support for loading proper U-Boot from unaligned location

Pali Rohár
2022-06-20T10:54:58Z

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

Signed-off-by: Pali Rohár <pali@kernel.org>
---
Changes in v2:
* Rebased on top of the U-Boot next branch, commit 98c4828740f4944462b7d9608b95d5b73850c7b0
---
drivers/mmc/fsl_esdhc_spl.c | 27 +++++++++++++++++++++++----
1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/fsl_esdhc_spl.c b/drivers/mmc/fsl_esdhc_spl.c
index 760f13d24018..54bf8152ca7a 100644
--- a/drivers/mmc/fsl_esdhc_spl.c
+++ b/drivers/mmc/fsl_esdhc_spl.c
@@ -58,10 +58,10 @@ void __noreturn mmc_boot(void)
{
__attribute__((noreturn)) void (*uboot)(void);
uint blk_start, blk_cnt, err;
+ u32 blk_off;
#ifndef CONFIG_FSL_CORENET
uchar *tmp_buf;
u32 blklen;
- u32 blk_off;
uchar val;
#ifndef CONFIG_SPL_FSL_PBL
u32 val32;
@@ -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