Re: [U-Boot] [RFC PATCH] fpga: zynq: Add encrypted bitstream support with auto detect

11 Jun 2018

Hi Stefan,
Interesting, I got your point. First of all,  Could you please let me know on how do you created the encrypted bitstream?
I hope this is not the Xilinx bootgen flow(may be through other Xilinx flow) because, I don't think bootgen will update these fields while creating encrypted bitstream( need to re confirm on this) and my flow targets the Xilinx bootgen flow. 
Please let know your comments on this, based on which, will try to review and test your patch.
Thanks,
Siva
...
-----Original Message-----
From: stefan@herbrechtsmeier.net [mailto:stefan@herbrechtsmeier.net]
Sent: Friday, June 08, 2018 5:29 PM
To: Siva Durga Prasad Paladugu sivadur@xilinx.com
Cc: Stefan Herbrechtsmeier stefan.herbrechtsmeier@weidmueller.com;
u-boot@lists.denx.de; Michal Simek michal.simek@xilinx.com;
monstr@monstr.eu
Subject: [RFC PATCH] fpga: zynq: Add encrypted bitstream support with
auto detect
From: Stefan Herbrechtsmeier
stefan.herbrechtsmeier@weidmueller.com
Signed-off-by: Stefan Herbrechtsmeier
stefan.herbrechtsmeier@weidmueller.com

drivers/fpga/zynqpl.c | 73
++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 57 insertions(+), 16 deletions(-)

diff --git a/drivers/fpga/zynqpl.c b/drivers/fpga/zynqpl.c index
fd37d18..6622750 100644
--- a/drivers/fpga/zynqpl.c
+++ b/drivers/fpga/zynqpl.c
@@ -17,6 +17,7 @@
#define DEVCFG_CTRL_PCFG_PROG_B		0x40000000
 #define DEVCFG_CTRL_PCFG_AES_EFUSE_MASK	0x00001000
+#define DEVCFG_CTRL_PCAP_RATE_EN_MASK	0x02000000
 #define DEVCFG_ISR_FATAL_ERROR_MASK	0x00740040
 #define DEVCFG_ISR_ERROR_FLAGS_MASK	0x00340840
 #define DEVCFG_ISR_RX_FIFO_OV		0x00040000
@@ -38,18 +39,16 @@
 #define CONFIG_SYS_FPGA_PROG_TIME	(CONFIG_SYS_HZ * 4) /* 4 s
*/
 #endif
+#define NOP_WORD	0x20000000
+#define CTRL0_WORD	0x3000a001
+#define MASK_WORD	0x3000c001
 #define DUMMY_WORD	0xffffffff
+#define CTRL0_DEC_MASK	BIT(6)



/* Xilinx binary format header */
+#define MAX_DUMMY_WORD_COUNT	8
 static const u32 bin_format[] = {

DUMMY_WORD, /* Dummy words */
DUMMY_WORD,
DUMMY_WORD,
DUMMY_WORD,
DUMMY_WORD,
DUMMY_WORD,
DUMMY_WORD,
DUMMY_WORD,
0x000000bb, /* Sync word */
0x11220044, /* Sync word */
DUMMY_WORD,

@@ -85,7 +84,23 @@ static u32 load_word(const void *buf, u32 swap)
   return word;
 }
-static u32 check_header(const void *buf)
+static void *skip_dummy_words(const void *buf) {

u32 *test = (u32 *)buf;
u32 i;

for (i = 0; i < MAX_DUMMY_WORD_COUNT; i++) {
if (load_word(&test[i], SWAP_NO) != DUMMY_WORD) {


	debug("%s: Found no dummy word at position



%d/%x\n",

	      __func__, i, (u32)&test[i]);


	return &test[i];


}


}

return &test[i];

+}



+static u32 check_header(const void *buf, bool *encrypted)
 {
   u32 i, pattern;
   int swap = SWAP_NO;
@@ -93,6 +108,8 @@ static u32 check_header(const void *buf)
debug("%s: Let's check bitstream header\n", __func__);

test = (u32 *)skip_dummy_words(buf);
/* Checking that passing bin is not a bitstream */
 for (i = 0; i < ARRAY_SIZE(bin_format); i++) {
  pattern = load_word(&test[i], swap);

@@ -112,18 +129,34 @@ static u32 check_header(const void *buf)
debug("%s: %d/%x: pattern %x/%x bin_format\n",

__func__, i,
   	      (u32)&test[i], pattern, bin_format[i]);

if (pattern != bin_format[i]) {
  	debug("%s: Bitstream is not recognized\n",

__func__);
   		return 0;
   	}
   }

debug("%s: Found bitstream header at %x %s swapinng\n",

__func__,

     (u32)buf, swap == SWAP_NO ? "without" : "with");





test = &test[i];

/* Checking if passing bin is an encrypted bitstream */
if ((load_word(&test[0], swap) == NOP_WORD) &&
   (load_word(&test[1], swap) == MASK_WORD) &&


   (load_word(&test[2], swap) & CTRL0_DEC_MASK) &&


   (load_word(&test[3], swap) == CTRL0_WORD) &&


   (load_word(&test[4], swap) & CTRL0_DEC_MASK) &&


   (load_word(&test[5], swap) == NOP_WORD))


*encrypted = true;


else
*encrypted = false;



debug("%s: Found %sencrypted bitstream header at %x %s

swapping\n",

     __func__, *encrypted ? "" : "un", (u32)buf,


     swap == SWAP_NO ? "without" : "with");


return swap;


}
-static void *check_data(u8 *buf, size_t bsize, u32 *swap)
+static void *check_data(u8 *buf, size_t bsize, u32 *swap, bool
+*encrypted)
 {
   u32 word, p = 0; /* possition */
@@ -136,7 +169,7 @@ static void *check_data(u8 *buf, size_t bsize, u32
*swap)
   	if (word == DUMMY_WORD) {
   		debug("%s: Found dummy word at position
%x/%x\n",
   		      __func__, p, (u32)&buf[p]);

	*swap = check_header(&buf[p]);




	*swap = check_header(&buf[p], encrypted);
if (*swap) {
	/* FIXME add full bitstream checking here */
	return &buf[p];



@@ -191,7 +224,7 @@ static int zynq_dma_transfer(u32 srcbuf, u32
srclen, u32 dstbuf, u32 dstlen)
   return FPGA_SUCCESS;
 }
-static int zynq_dma_xfer_init(bitstream_type bstype)
+static int zynq_dma_xfer_init(bitstream_type bstype, bool encrypted)
 {
   u32 status, control, isr_status;
   unsigned long ts;
@@ -291,6 +324,13 @@ static int zynq_dma_xfer_init(bitstream_type
bstype)
   	writel(DEVCFG_STATUS_DMA_DONE_CNT_MASK,
&devcfg_base->status);
   }

control = readl(&devcfg_base->ctrl);
if (encrypted)
control |= DEVCFG_CTRL_PCAP_RATE_EN_MASK;


else
control &= ~DEVCFG_CTRL_PCAP_RATE_EN_MASK;


writel(control, &devcfg_base->ctrl);
return FPGA_SUCCESS;

}
@@ -336,10 +376,11 @@ static int zynq_validate_bitstream(xilinx_desc
*desc, const void *buf,
   			   size_t bsize, u32 blocksize, u32 *swap,
   			   bitstream_type *bstype)
 {

bool encrypted = false;
u32 *buf_start;
u32 diff;


buf_start = check_data((u8 *)buf, blocksize, swap);


buf_start = check_data((u8 *)buf, blocksize, swap, &encrypted);
if (!buf_start)
return FPGA_FAIL;


@@ -358,7 +399,7 @@ static int zynq_validate_bitstream(xilinx_desc
*desc, const void *buf,
   	return FPGA_FAIL;
   }

if (zynq_dma_xfer_init(*bstype))


if (zynq_dma_xfer_init(*bstype, encrypted))
return FPGA_FAIL;
return 0;


--
2.7.4

    