--- a/loadtools/flamdsec.c	Fri Dec 01 08:05:31 2023 +0000
+++ b/loadtools/flamdsec.c	Sat Dec 02 04:21:59 2023 +0000
@@ -1,12 +1,14 @@
 /*
- * This module is a place to implement commands that are specific to
- * security features (OTP, sector locking) of AMD-style flash chips.
+ * This module is a place to implement commands and functions for
+ * sector write-protection (locking and unlocking, checking current
+ * lock state) on AMD-style flash chips.
  */
 
 #include <sys/types.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include "flash.h"
 
 extern struct flash_bank_info flash_bank_info[2];
@@ -168,3 +170,140 @@
 	}
 	return(0);
 }
+
+static
+plj_ppb_write_op(base_addr, is_erase, retp)
+	uint32_t base_addr;
+	uint16_t *retp;
+{
+	if (do_w16(base_addr + 0xAAA, 0xAA)) {
+bad_w16:	fprintf(stderr,
+	"unexpected response to w16 in PPB command sequence - aborting\n");
+		return(-1);
+	}
+	if (do_w16(base_addr + 0x554, 0x55))
+		goto bad_w16;
+	if (do_w16(base_addr + 0xAAA, 0x60))
+		goto bad_w16;
+	if (do_w16(base_addr + 4, is_erase ? 0x60 : 0x68))
+		goto bad_w16;
+	usleep(1200);			/* per S29PL-J datasheet */
+	if (do_w16(base_addr + 4, is_erase ? 0x40 : 0x48))
+		goto bad_w16;
+	if (do_r16(base_addr + 4, retp) < 0)
+		return(-1);
+	return(0);
+}
+
+plj_ppb_program_one(bi, sector_addr)
+	struct flash_bank_info *bi;
+	uint32_t sector_addr;
+{
+	uint16_t stat;
+	unsigned pulsecnt;
+	int rc;
+
+	for (pulsecnt = 0; pulsecnt < 25; ) {
+		rc = plj_ppb_write_op(bi->base_addr + sector_addr, 0, &stat);
+		if (rc < 0)
+			return(rc);
+		pulsecnt++;
+		if (!(stat & 1))
+			continue;
+		printf("PPB 0x%X programmed with %u pulse%s\n", sector_addr,
+			pulsecnt, pulsecnt > 1 ? "s" : "");
+		return(0);
+	}
+	printf("PPB 0x%X programming FAILED, tried %u pulses\n", sector_addr,
+		pulsecnt);
+	return(-1);
+}
+
+plj_ppb_program_all_single(bank)
+{
+	struct flash_bank_info *bi = flash_bank_info + bank;
+	struct amd_lock_info *li = bi->amd_lock;
+	struct lock_group_desc *grp;
+	uint32_t offset;
+	unsigned ng, nb;
+	int rc;
+
+	offset = 0;
+	for (ng = 0; ng < li->ngroups; ng++) {
+		grp = li->groups + ng;
+		for (nb = 0; nb < grp->nblocks; nb++) {
+			rc = plj_ppb_program_one(bi, offset);
+			if (rc < 0)
+				return(rc);
+			offset += grp->block_size;
+		}
+	}
+	return(0);
+}
+
+plj_ppb_program_all_dualbank(reqbank)
+{
+	int altbank = !reqbank;
+	int rc;
+
+	if (flash_detect(altbank, 0) < 0)
+		return(-1);
+	if (flash_bank_info[0].device != flash_bank_info[1].device) {
+		fprintf(stderr, "error: mismatch between two flash banks\n");
+		return(-1);
+	}
+	printf("Programming all PPBs in flash bank 0\n");
+	rc = plj_ppb_program_all_single(0);
+	if (rc < 0)
+		return(-1);
+	printf("Programming all PPBs in flash bank 1\n");
+	rc = plj_ppb_program_all_single(1);
+	if (rc < 0)
+		return(-1);
+	return(0);
+}
+
+static
+plj_ppb_erase_cycle(bank)
+{
+	struct flash_bank_info *bi = flash_bank_info + bank;
+	uint16_t stat;
+	unsigned pulsecnt;
+	int rc;
+
+	printf("Performing PPB erase cycle\n");
+	for (pulsecnt = 0; pulsecnt < 1000; ) {
+		rc = plj_ppb_write_op(bi->base_addr, 1, &stat);
+		if (rc < 0)
+			return(rc);
+		pulsecnt++;
+		if (stat & 1)
+			continue;
+		printf("PPB erase cycle succeeded after %u pulse%s\n",
+			pulsecnt, pulsecnt > 1 ? "s" : "");
+		return(0);
+	}
+	printf("PPB erase cycle FAILED, tried %u pulses\n", pulsecnt);
+	return(-1);
+}
+
+plj_ppb_erase_all_single(bank)
+{
+	int rc;
+
+	printf("Programming all PPBs before erase cycle\n");
+	rc = plj_ppb_program_all_single(bank);
+	if (rc < 0)
+		return(-1);
+	return plj_ppb_erase_cycle(bank);
+}
+
+plj_ppb_erase_all_dualbank(reqbank)
+{
+	int rc;
+
+	rc = plj_ppb_program_all_dualbank(reqbank);
+	if (rc < 0)
+		return(-1);
+	return plj_ppb_erase_cycle(reqbank);
+}