On Fri, Mar 22, 2019 at 05:01:55PM +0800, Ley Foon Tan wrote:
On Fri, Mar 22, 2019 at 9:31 AM Tom Rini trini@konsulko.com wrote:
On Fri, Mar 22, 2019 at 09:28:21AM +0800, Ley Foon Tan wrote:
On Thu, Mar 21, 2019 at 7:22 PM Tom Rini trini@konsulko.com wrote:
On Fri, Mar 22, 2019 at 01:12:14AM +0800, Ley Foon Tan wrote:
Add "%ll" modifier support for tiny printf.
- Tested on ARM32 and ARM64 systems.
- Tested "%lld", "%llu", "%llx" and "%p" format with minimum and maximum ranges. Compared tiny printf output with full printf.
Signed-off-by: Ley Foon Tan ley.foon.tan@intel.com
lib/tiny-printf.c | 42 +++++++++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 13 deletions(-)
What's the use case for this, how much does it grow the size, and can the code in question be changed to use a different format modifier or be debug() instead? Tiny printf isn't intended to cover all formats but rather still allow some amount of printf on constrained systems. Thanks!
-- Tom
This is to support printf %lld, %llu and %llx and 64-bit %p when CONFIG_USE_TINY_PRINTF=y is enabled. In 64-bit system, phys_size_t and phys_addr_t are unsigned long long. Printf these variables will see rubbish in existing tiny printf.
Example %ll printf; printf("9223372036854775807 ==> %lld \n", (long long)9223372036854775807); printf("0xffffffffffffffff ==> 0x%llx \n", (unsigned long long)0xffffffffffffffff);
There are few issues I've noticed with original tiny printf:
- Some common codes use %ll format
- %p in tiny printf only support 32-bit, it can't support 64-bit address.
If DEBUG is defined and with tiny printf. You can see all rubbish x for %llx printf. The most serious issue is it cause system hang at line below (printf from common code). addr=x level=0 idx=x PTE at level 16384: x Creating table for virt 0xx Setting 4000 to addr=5000 addr=x level=0 idx=x PTE at level 16384: x idx=x PTE at level 20480: x Checking if pte fits for virt=x size=x blocksize=x Setting PTE 5000 to block virt=x addr=x level=1073741824 idx=x PTE at level 16384: x addr=x level=1073741824 idx=x PTE at level 16384: x idx=x PTE 1 at level 20488: x Checking if pte fits for virt=x size=x blocksize=x Setting PTE 5008 to block virt=x addr=x level=
Example output after apply this patch: idx=0 PTE 8000 at level 0: 9003 idx=3 PTE 9018 at level 1: a003 Checking if pte fits for virt=c0600000 size=1fa00000 blocksize=40000000 addr=c0600000 level=2 idx=0 PTE 8000 at level 0: 9003 idx=3 PTE 9018 at level 1: a003
ARM64:
It increase 200 bytes.
Before: text data bss dec hex filename 69618 5296 232 75146 1258a spl/u-boot-spl
After: text data bss dec hex filename 69818 5296 232 75346 12652 spl/u-boot-spl
ARM32:
It increase 644 bytes.
Before: text data bss dec hex filename 31825 2968 132 34925 886d spl/u-boot-spl
After: text data bss dec hex filename 32469 2968 132 35569 8af1 spl/u-boot-spl
That's a lot, especially since we have tiny printf platforms that are really on the edge. Can you just not use TINY_PRINTF when using DEBUG?
Yes, we can. Our platform still have space for this.
OK, then lets just defer this, thanks!