Hi Pali,
On Sun, 11 Sept 2022 at 03:39, Pali Rohár pali@kernel.org wrote:
32-bit U-Boot builds cannot use more than around 2 GB of DDR memory. But on some platforms/boards it is possible to connect also 4 GB SODIMM DDR memory. U-Boot currently prints only effective size of RAM which can use, which may be misleading as somebody would expect that this line prints total size of connected DDR modules. So change show_dram_config code to prints both real and effective DRAM size if they are different. If they are same then print just one number like before. It is possible that effective size is just few bytes smaller than the real size, so print both numbers only in case function print_size() prints formats them differently.
Signed-off-by: Pali Rohár pali@kernel.org
common/board_f.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/common/board_f.c b/common/board_f.c index 9e34fbee147e..3131a06db940 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -54,6 +54,7 @@ #include <asm/sections.h> #include <dm/root.h> #include <linux/errno.h> +#include <linux/log2.h>
/*
- Pointer to initial global data area
@@ -213,6 +214,30 @@ static int announce_dram_init(void) return 0; }
+/*
- Check if the sizes in their natural units written in decimal format with
- one fraction number are same.
- */
+static int sizes_near(unsigned long long size1, unsigned long long size2) +{
unsigned int size1_scale = ilog2(size1) / 10 * 10;unsigned int size1_val = (10 * size1 + ((1ULL << size1_scale) >> 1)) >> size1_scale;unsigned int size2_scale = ilog2(size2) / 10 * 10;unsigned int size2_val = (10 * size2 + ((1ULL << size2_scale) >> 1)) >> size2_scale;
Can you put that expression into a function with a comment, etc.? It is a bit hard to understand.
if (size1_val == 10240) {size1_val = 10;size1_scale += 10;}if (size2_val == 10240) {size2_val = 10;size2_scale += 10;}
If you are doing the same thing to each, why bother? It should not affect the expression below, should it? :
return size1_scale == size2_scale && size1_val == size2_val;+}
static int show_dram_config(void) { unsigned long long size; @@ -229,7 +254,11 @@ static int show_dram_config(void) } debug("\nDRAM: ");
print_size(size, "");
print_size(gd->ram_size, "");if (!sizes_near(gd->ram_size, size)) {printf(" (effective ");print_size(size, ")");} board_add_ram_info(0); putc('\n');-- 2.20.1
Can we make this testable somehow? You could put the new code into a lib/ function, perhaps, and call it from a C unit test in test/lib ?
Regards, Simon