util/amdfwtool: Clarify call to fletcher32

The fletcher32 algorithm generates a sum over a range of 16-bit
WORDs.  Change the function's interface to be more generic,
accepting a more intuitive size in BYTEs.  Don't require the
caller to understand the nature of the algorithm and convert to
WORDs prior to calling.

TEST=Verify no difference in amdfw.rom for google/grunt before
     and after the patch is applied

Change-Id: Iad70558347cbdb3c51bd598479ee4484219c0869
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31728
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Marshall Dawson 2019-02-24 07:18:44 -07:00 committed by Martin Roth
parent 239286ca44
commit 8a45a4dc3f
1 changed files with 14 additions and 9 deletions

View File

@ -121,12 +121,15 @@ typedef unsigned short uint16_t;
* inserted 8 bytes after the beginning of the file.
* stderr: Used to print out error messages.
*/
static uint32_t fletcher32(const uint16_t *pptr, int length)
static uint32_t fletcher32(const void *data, int length)
{
uint32_t c0;
uint32_t c1;
uint32_t checksum;
int index;
const uint16_t *pptr = data;
length /= 2;
c0 = 0xFFFF;
c1 = 0xFFFF;
@ -138,13 +141,15 @@ static uint32_t fletcher32(const uint16_t *pptr, int length)
c0 += *(pptr++);
c1 += c0;
if ((index % 360) == 0) {
c0 = (c0 & 0xFFFF) + (c0 >> 16); // Sum0 modulo 65535 + the overflow
c1 = (c1 & 0xFFFF) + (c1 >> 16); // Sum1 modulo 65535 + the overflow
/* Sums[0,1] mod 64K + overflow */
c0 = (c0 & 0xFFFF) + (c0 >> 16);
c1 = (c1 & 0xFFFF) + (c1 >> 16);
}
}
c0 = (c0 & 0xFFFF) + (c0 >> 16); // Sum0 modulo 65535 + the overflow
c1 = (c1 & 0xFFFF) + (c1 >> 16); // Sum1 modulo 65535 + the overflow
/* Sums[0,1] mod 64K + overflow */
c0 = (c0 & 0xFFFF) + (c0 >> 16);
c1 = (c1 & 0xFFFF) + (c1 >> 16);
checksum = (c1 << 16) | c0;
return checksum;
@ -331,9 +336,9 @@ static void fill_psp_head(psp_directory_table *pspdir, uint32_t count)
/* checksum everything that comes after the Checksum field */
pspdir->header.checksum = fletcher32(
(void *)&pspdir->header.num_entries,
(count * sizeof(psp_directory_entry)
count * sizeof(psp_directory_entry)
+ sizeof(pspdir->header.num_entries)
+ sizeof(pspdir->header.reserved)) / 2);
+ sizeof(pspdir->header.reserved));
}
static uint32_t integrate_firmwares(char *base, uint32_t pos,
@ -848,11 +853,11 @@ int main(int argc, char **argv)
combo_dir->header.reserved[1] = 0;
combo_dir->header.checksum = fletcher32(
(void *)&combo_dir->header.num_entries,
(1 * sizeof(psp_directory_entry)
1 * sizeof(psp_directory_entry)
+ sizeof(combo_dir->header.num_entries)
+ sizeof(combo_dir->header.lookup)
+ sizeof(combo_dir->header.reserved[0])
+ sizeof(combo_dir->header.reserved[1])) / 2);
+ sizeof(combo_dir->header.reserved[1]));
#else
current = integrate_psp_firmwares(rom, current, psp2dir,
amd_psp2_fw_table, rom_size);