diff --git a/README b/README index 1e2d4d3..6a601d2 100644 --- a/README +++ b/README @@ -3305,6 +3305,15 @@ List of environment variables (most likely not complete): This can be used to load and uncompress arbitrary data. + fdt_high - if set this restricts the maximum address that the + flattened device tree will be copied into upon boot. + If this is set to the special value 0xFFFFFFFF then + the fdt will not be copied at all on boot. For this + to work it must reside in writable memory, have + sufficient padding on the end of it for u-boot to + add the information it needs into it, and the memory + must be accessible by the kernel. + i2cfast - (PPC405GP|PPC405EP only) if set to 'y' configures Linux I2C driver for fast mode (400kHZ). This environment variable is used in diff --git a/common/image.c b/common/image.c index e542a57..c6cd85e 100644 --- a/common/image.c +++ b/common/image.c @@ -1234,8 +1234,10 @@ int boot_relocate_fdt (struct lmb *lmb, char **of_flat_tree, ulong *of_size) { void *fdt_blob = *of_flat_tree; void *of_start = 0; + char *fdt_high; ulong of_len = 0; int err; + int disable_relocation = 0; /* nothing to do */ if (*of_size == 0) @@ -1249,26 +1251,62 @@ int boot_relocate_fdt (struct lmb *lmb, char **of_flat_tree, ulong *of_size) /* position on a 4K boundary before the alloc_current */ /* Pad the FDT by a specified amount */ of_len = *of_size + CONFIG_SYS_FDT_PAD; - of_start = (void *)(unsigned long)lmb_alloc_base(lmb, of_len, 0x1000, - getenv_bootm_mapsize() + getenv_bootm_low()); + + /* If fdt_high is set use it to select the relocation address */ + fdt_high = getenv("fdt_high"); + if (fdt_high) { + void *desired_addr = (void *)simple_strtoul(fdt_high, NULL, 16); + + if (((ulong) desired_addr) == ~0UL) { + /* All ones means use fdt in place */ + desired_addr = fdt_blob; + disable_relocation = 1; + } + if (desired_addr) { + of_start = + (void *)(ulong) lmb_alloc_base(lmb, of_len, 0x1000, + ((ulong) + desired_addr) + + of_len); + if (desired_addr && of_start != desired_addr) { + puts("Failed using fdt_high value for Device Tree"); + goto error; + } + } else { + of_start = + (void *)(ulong) mb_alloc(lmb, of_len, 0x1000); + } + } else { + of_start = + (void *)(ulong) lmb_alloc_base(lmb, of_len, 0x1000, + getenv_bootm_mapsize() + + getenv_bootm_low()); + } if (of_start == 0) { puts("device tree - allocation error\n"); goto error; } - debug ("## device tree at %p ... %p (len=%ld [0x%lX])\n", - fdt_blob, fdt_blob + *of_size - 1, of_len, of_len); + if (disable_relocation) { + /* We assume there is space after the existing fdt to use for padding */ + fdt_set_totalsize(of_start, of_len); + printf(" Using Device Tree in place at %p, end %p\n", + of_start, of_start + of_len - 1); + } else { + debug ("## device tree at %p ... %p (len=%ld [0x%lX])\n", + fdt_blob, fdt_blob + *of_size - 1, of_len, of_len); - printf (" Loading Device Tree to %p, end %p ... ", - of_start, of_start + of_len - 1); + printf (" Loading Device Tree to %p, end %p ... ", + of_start, of_start + of_len - 1); - err = fdt_open_into (fdt_blob, of_start, of_len); - if (err != 0) { - fdt_error ("fdt move failed"); - goto error; + err = fdt_open_into (fdt_blob, of_start, of_len); + if (err != 0) { + fdt_error ("fdt move failed"); + goto error; + } + puts ("OK\n"); } - puts ("OK\n"); *of_flat_tree = of_start; *of_size = of_len;