diff options
| author | Tom Rini <[email protected]> | 2021-10-06 12:26:33 -0400 |
|---|---|---|
| committer | Tom Rini <[email protected]> | 2021-10-06 13:46:31 -0400 |
| commit | ea67f467a43e4c8852bd1ce1bb75f5dc6c3788d1 (patch) | |
| tree | 1bbf310f2b22ad465d5698bfdf71347129834561 /doc | |
| parent | 7240e1b8f94a56db88a2af688cad27e2e6545302 (diff) | |
| parent | 6115f1c4fe81015369e110ea9830a6e36710677c (diff) | |
Merge branch '2021-10-06-assorted-improvements'
- Use better values for ACPI OEM_VERSION
- Assorted NAND related Kconifg migrations and another dependency fix
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.nand | 71 | ||||
| -rw-r--r-- | doc/develop/version.rst | 1 |
2 files changed, 0 insertions, 72 deletions
diff --git a/doc/README.nand b/doc/README.nand index ec461b2dc93..ffcea907999 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -175,11 +175,6 @@ Configuration Options: flexibility, so that one day we can eliminate the old mechanism. - CONFIG_SYS_NAND_ONFI_DETECTION - Enables detection of ONFI compliant devices during probe. - And fetching device parameters flashed on device, by parsing - ONFI parameter page. - Platform specific options ========================= CONFIG_NAND_OMAP_GPMC @@ -205,72 +200,6 @@ Platform specific options so those platforms should use CONFIG_SPL_NAND_SIMPLE for enabling SPL-NAND driver with software ECC correction support. - CONFIG_NAND_OMAP_ECCSCHEME - On OMAP platforms, this CONFIG specifies NAND ECC scheme. - It can take following values: - OMAP_ECC_HAM1_CODE_SW - 1-bit Hamming code using software lib. - (for legacy devices only) - OMAP_ECC_HAM1_CODE_HW - 1-bit Hamming code using GPMC hardware. - (for legacy devices only) - OMAP_ECC_BCH4_CODE_HW_DETECTION_SW - 4-bit BCH code (unsupported) - OMAP_ECC_BCH4_CODE_HW - 4-bit BCH code (unsupported) - OMAP_ECC_BCH8_CODE_HW_DETECTION_SW - 8-bit BCH code with - - ecc calculation using GPMC hardware engine, - - error detection using software library. - - requires CONFIG_BCH to enable software BCH library - (For legacy device which do not have ELM h/w engine) - OMAP_ECC_BCH8_CODE_HW - 8-bit BCH code with - - ecc calculation using GPMC hardware engine, - - error detection using ELM hardware engine. - OMAP_ECC_BCH16_CODE_HW - 16-bit BCH code with - - ecc calculation using GPMC hardware engine, - - error detection using ELM hardware engine. - - How to select ECC scheme on OMAP and AMxx platforms ? - ----------------------------------------------------- - Though higher ECC schemes have more capability to detect and correct - bit-flips, but still selection of ECC scheme is dependent on following - - hardware engines present in SoC. - Some legacy OMAP SoC do not have ELM h/w engine thus such - SoC cannot support BCHx_HW ECC schemes. - - size of OOB/Spare region - With higher ECC schemes, more OOB/Spare area is required to - store ECC. So choice of ECC scheme is limited by NAND oobsize. - - In general following expression can help: - NAND_OOBSIZE >= 2 + (NAND_PAGESIZE / 512) * ECC_BYTES - where - NAND_OOBSIZE = number of bytes available in - OOB/spare area per NAND page. - NAND_PAGESIZE = bytes in main-area of NAND page. - ECC_BYTES = number of ECC bytes generated to - protect 512 bytes of data, which is: - 3 for HAM1_xx ecc schemes - 7 for BCH4_xx ecc schemes - 14 for BCH8_xx ecc schemes - 26 for BCH16_xx ecc schemes - - example to check for BCH16 on 2K page NAND - NAND_PAGESIZE = 2048 - NAND_OOBSIZE = 64 - 2 + (2048 / 512) * 26 = 106 > NAND_OOBSIZE - Thus BCH16 cannot be supported on 2K page NAND. - - However, for 4K pagesize NAND - NAND_PAGESIZE = 4096 - NAND_OOBSIZE = 224 - ECC_BYTES = 26 - 2 + (4096 / 512) * 26 = 210 < NAND_OOBSIZE - Thus BCH16 can be supported on 4K page NAND. - - CONFIG_NAND_OMAP_GPMC_PREFETCH On OMAP platforms that use the GPMC controller (CONFIG_NAND_OMAP_GPMC_PREFETCH), this options enables the code that diff --git a/doc/develop/version.rst b/doc/develop/version.rst index 8f3231b7611..5c9046aa17a 100644 --- a/doc/develop/version.rst +++ b/doc/develop/version.rst @@ -87,7 +87,6 @@ fields. For example:: #define U_BOOT_DATE "Jan 06 2021" (US format only) #define U_BOOT_TIME "08:50:36" (24-hour clock) #define U_BOOT_TZ "-0700" (Time zone in hours) - #define U_BOOT_BUILD_DATE 0x20210106 (hex yyyymmdd format) #define U_BOOT_EPOCH 1609948236 The Epoch is the number of seconds since midnight on 1/1/70. You can convert |
